Access to Space: The Future of U.S. Space

Transportation Systems

April 1990

OTA-ISC-415

NTIS order #PB90-253154
Recommended Citation:

U.S. Congress, Office of Technology Assessment, Access to Space: The Future of U.S. Space

Transportation Systems, OTA-ISC-415 (Washington, DC: U.S. Government Printing Office,

April 1990).

Library of Congress Catalog Card Number 89-600710

For sale by the Superintendent of Documents

U.S. Government Printing Office, Washington, DC 20402-9325

(order form can be found in the back of this report)
Foreword

The United States today possesses a capable fleet of cargo and crew-carrying launch

systems, managed by the National Aeronautics and Space Administration, the Department of

Defense, and the private sector. Emerging technologies offer the promise, by the turn of the

century, of new launch systems that may reduce cost while increasing performance, reliability,

and operability.

Continued exploration and exploitation of space will depend on a fleet of versatile and

reliable launch vehicles. Yet, uncertainty about the nature of U.S. space program goals and the

schedule for achieving them, as well as the stubbornly high cost of space transportation, makes

choosing among the many space transportation alternatives extremely difficult. Can existing

and potential future systems meet the demand for launching payloads in a timely, reliable, and

cost-effective manner? What investments should the Government make in future launch

systems and when? What new crew-carrying and cargo launchers are needed? Can the Nation

afford them?

This special report explores these and many other questions. It is the final, summarizing

report in a series of products from a broad assessment of space transportation technologies

undertaken by OTA for the Senate Committee on Commerce, Science, and Transportation,

and the House Committee on Science, Space, and Technology. In the course of the assessment,

OTA has published the special reports, Launch Options for the Future: A Buyer’s Guide and

Round Trip to Orbit: Human Spaceflight Alternatives; the technical memorandum, Reducing

Launch Operations Costs: New Technologies and Practices; and the background papers, Big

Dumb Boosters: A Low-Cost Space Transportation Option? and Affordable Spacecraft:

Design and Launch Alternatives.

In undertaking this effort, OTA sought the contributions of a wide spectrum of

knowledgeable individuals and organizations. Some provided information, others reviewed

drafts. OTA gratefully acknowledges their contributions of time and intellectual effort. OTA

also appreciates the help and cooperation of NASA and the Air Force. As with all OTA reports,

the content of this special report is the sole responsibility of the Office of Technology

Assessment and does not necessarily represent the views of our advisors or reviewers.

Directo r

. . .

Ill
Advisory Panel on

Access to Space: The Future of U.S. Space Transportation Systems

M. Granger Morgan, Chair

Head, Department of Engineering and Public Policy

Carnegie-Mellon University

I.M. Bernstein

Provost and Academic Vice President

Illinois Institute of Technology

Michael A. Berta

Assistant Division Manager

Space and Communications Group

Hughes Aircraft Co.

Richard E. Brackeen

President & CEO

Matra Aero Space, Inc.

Edward T. Gerry

President

W. J. Schafer Associates, Inc.

Jerry Grey

Director, Science and Technology Policy

American Institute of Aeronautics and Astronautics

William H. Heiser

Consultant

Otto W. Hoernig, Jr.

Vice President

Contel/American Satellite Corp.

Donald B. Jacobs

Vice President, Space Systems Division

Boeing Aerospace Co.

John Logsdon

Director, Graduate Program in Science,

Technology, and Public Policy

George Washington University

Hugh F. Loweth

Consultant

Anthony J. Macina

Program Manager

IBM Federal Systems Division

George B. Merrick

Vice President

North American Space Operations

Rockwell International Corp.

Alan Parker

Consultant

Gerard Piel

Chairman Emeritus

Scientific American

Bryce Poe, 11

General, USAF (retired)

Consultant

Ben R. Rich

Vice President and General Manager

Lockheed Corp.

Sally K. Ride

Director

California Space Institute

Tom Rogers

President

The Sophron Foundation

Richard G. Smith

Senior Vice President

JLC Aerospace Corp.

William Zersen

Consultant

NOTE: OTA appreciates the valuable assistance and thoughtful critiques provided by the advisory panel members. The views

expressed in this OTA report, however, are the sole responsibility of the Office of Technology Assessment. Participation on

the advisory panel does not imply endorsement of the report.
OTA Project Staff

Access to Orbit: The Future of U.S. Space Transportation Systems

Lionel S. Johns, Assistant Director, OTA

Energy, Materials, and International Security Division

Alan Shaw, International Security and Commerce Program Manager

Ray A. Williamson, Project Director (from January 16, 1989)

Richard DalBello, Project Director (until January 16, 1989)

Steven W. Altes (through September 1988)

Eric O. Basques (through August 1989)

Michael B. Callaham

Arthur Charo

Gordon Law

Contractors

Trudy E. Bell

Leonard David

Henry Hertzfeld

Administrative Staff

Jannie Home (through November 1988)

Cecile Parker (through March 1989)

Donna Reynolds

Jackie Robinson

Louise Staley
Acknowledgments

The following organizations generously provided OTA with information and suggestions:

Aerospace Corp. NASA Johnson Space Center

Boeing Aerospace Operations Co. NASA Kennedy Space Center

General Dynamics NASA Langley Research Center

Lockheed Space Operations Co. NASA Marshall Space Flight Center

Martin Marietta DoD Strategic Defense Initiative Organization

McDonnell Douglas U.S. Air Force Directorate of Space Systems

NASA Headquarters U.S. Air Force Space Division

This report has also benefited from the advice of many space transportation experts from the Government and the

private sector. OTA especially would like to thank the following individuals for their assistance and support. The views

expressed in this report however, are the sole responsibility of the Office of Technology Assessment.

Jim Bain Ron Harris Rand Simberg

NASA Headquarters NASA Headquarters Rockwell International

Peter Banks Capt. David Hart Maj. Jess Sponable

Stanford University U.S. Navy U.S. Air Force

James Bennett Lynn Heninger Charles Teixeira

American Rocket Corp. NASA Headquarters Johnson Space Center, NASA

Darrell Branscome Max Henrion L.O. Wear

NASA Headquarters Rockwell International Corp. Marshall Space Flight Center, NASA

Radford Byerly David Moore Barbara Zedina

University of Colorado Congressional Budget Office Orbital Sciences Corp.

H.J. Dinenno Lt. Col. Kenneth E. Murphy Lowell Zoeller

Rockwell International Strategic Defense Initiative Marshall Space Flight Center, NASA

Jerry Fitts Organization

NASA Headquarters Lt. Col. Robert B. Preston

John Fredericks U.S. Air Force

McDonnell Douglas Corp. William Rock

Daniel L. Gregory Kennedy Space Center, NASA

Boeing Aerospace Co.
Related OTA Reports

Civilian Space

Advanced Space Transportation Technologies Assessment

Affordable Spacecraft: Design and Launch Alternatives. OTA-BP-ISC-60, January 1990. GPO stock #052-003-01 174-

3;$2.25 .

Round Trip to Orbit: Human Spaceflight Alternatives. OTA-ISC-419, August 1989, GPO stock #052-003-01 155-7;

$5.50.

Launch Options for the Future: A Buyer’s Guide. OTA-ISC-383, July 1988. NTIS order #PB 89-1 142681AS.

Reducing Launch Operations Costs: New Technologies and Practices. OTA-TM-EC-28, September 1988. GPO stock

#052-003-01 118-2; $4.50.

Big Dumb Boosters: A Low-Cost Space Transportation Option? OTA Background Paper, February 1989. (available

from OTA’s International Security-and Commerce Program)

Other Reports

Commercial Newsgathering From Space. OTA-TM-ISC-40, May 1987. NTIS order #PB 87-235 396/XAB.

Space Stations and the Law: Selected Legal issues. OTA-BP-ISC-41, September 1986. NTIS order #PB 87-118

220/AS.

International Cooperation and Competition in Civilian Space Activities. OTA-ISC-239, July 1985. NTIS order #PB

87-136 842/AS.

U.S.-Soviet Cooperation in Space. OTA-TM-STI-27, July 1985. NTIS order #PB 86-114 758/AS.

Civilian Space Stations and the U.S. Future in Space. OTA-STI-241, November 1984. GPO stock #052-003-00969-2;

$7.50.

Remote Sensing and the Private Sector: Issues for Discussion. OTA-TM-ISC-20, March 1984. NTIS order #PB 84-180

‘777.

Salyut: Soviet Steps Toward Permanent Human Presence in Space. OTA-TM-STI- 14, December 1983. NTIS order #PB

84-181 437/AS.

UNISPACE ’82: A Context for International Cooperation and Competition. OTA-TM-MC-26, March 1983. NTIS

order #PB 83-201848.

Space Science Research in the United States. OTA-TM-STI-19, September 1982. NTIS order #PB 83-166512.

Civilian Space Policy and Applications. OTA-STI-177, June 1982. NTIS order #PB 82-234444.

Radio frequency Use and Management: Impacts From the World Administrative Radio Conference of 1979.

OTA-CIT-163, January 1982. NTIS order #PB 82-177536.

Solar Power Satellite Systems and Issues. OTA-E-144, August 1981. NTIS order #PB 82-108846.

Military Space

SDI: Technology, Survivability, and Softwre. OTA-ISC-353, May 1988. GPO stock #052-003-01084-4; $12.00.

Anti-Satellite Weapons, Countermeasures, and Arms Control. OTA-ISC-281, September 1985. NTIS order #PB

86-182 953/AS.

Ballistic Missile Defense Technologies. OTA-ISC-254, September, 1985. NTIS order #PB 86-182 961/AS.

Arms Control in Space. OTA-BP-ISC-28, May 1984. NTIS order #PB 84-198 209/AS.

Directed Energy Missile Defense in Space. OTA-BP-ISC-26, April 1984. NTIS order #PB 84-21011 I/AS.

NOTE: Reports are available through the GPO (U.S. Government Printing Office), Superintendent of Documents, Dept. 36-B M,

Washington, DC 20402 (202) 783-3238; and the NTIS (National Technical Information Service), 5285 Port Royal Road,

Spxingfleld, VA 22161, (703) 487-4650.

vii
Legislative Options for Space Transportation

Space Program Futures

Congress could choose to support the development of one or more of many different types of space

transportation systems. To determine which of these alternatives is most appropriate, Congress must first make

some broad decisions about the future of the United States in space. A commitment to key space program goals

will entail a similar commitment to one or more launch systems.

[f Congress wishes to:

Limit the expansion of

NASA and DoD space

programs:

Develop the capability to

launch small- and intermediate-size payloads

quickly and efficiently to

support DoD and civilian

needs:

Deploy Space Station Freedom by the end of the

century, while maintaining an aggressive NASA

science program:

Continue trend of launching heavier communications, navigation, and surveillance satellites and/or

pursue an aggressive Strategic Defensive Initiative

test program:

Deploy a full-scale spacebased ballistic missile defense system and/or dramatically increase the number and kind of other military space activities:

Establish a permanent

base on the Moon or send

humans to Mars:

Then it should:

Maintain existing launch systems and limit expenditures on future development options. Current capabilities are adequate to supply both NASA and

DoD if the present level of U.S. space activities is maintained.

Continue to support the development of small and intermediate capacity

launch systems. The U.S. private sector has the financial and technical

capacity to develop such systems on its own if a market for launching

small payloads exists.

Continue funding improvements to the Space Shuttle and other existing space

transportation systems and/or begin developing Shuttle-C: The existing

Space Shuttle can launch the Space Station, but will do so more

effectively with improvements or the assistance of a Shuttle-C. Although

Shuttle-C might not be as economical as other new cargo vehicles at high

launch rates, it would be competitive if only a few heavy-lift missions are

required each year.

Commit to the development of a new cargo vehicle for use early in the 21st

century. Although existing launch systems could be expanded to meet

such growth in payload weight, if demand is high, new, advanced systems

would be more reliable and cost-effective.

Commit to the development of a new cargo vehicle such as the Advanced

Launch System. Current launch systems are neither sufficiently economical to support full-scale space-based ballistic missile defense deployment,

nor reliable enough to support a dramatically increased military space

program.

Commit to the development of a new cargo vehicle(s) (Shuttle-C, Advanced

Launch System, or other system) and continue funding advanced, crewcarrying launch systems. Any major initiative beyond the Space Station

involving humans in space will require new launch systems.

.,. VIII
Improving U.S. Space Transportation Systems

Whichever broad program goals are selected, if Congress wishes to continue to improve the safety,

reliability, performance, and/or economy of U.S. launch systems, it has a number of possibilities from which

to choose. Several are listed below; they are not mutually exclusive, nor is the list exhaustive. Congress could

decide to proceed with one or more from each list of options. Because of the long lead times for the

development of space transportation systems, some decisions will have to be made in the next year or two.

Others can wait until the middle of this decade or later.

If Congress wishes to:

Improve cargo launch

system reliability or

performance:

Improve Space Shuttle system safety, reliability:

Maintain a sustainable Shuttle launch rate of 9 to 11

launches per year:

Reduce risks to successful

Space Station assembly:

Develop the technology base

and plan for building new

crew-carrying launch

systems:

Provide for emergency crew

return from the Space

Station:

If Congress wishes to:

Build safer, more reliable

crew-carrying launch

systems:

Improve cargo launch

system reliability and

reduce costs:

Increase operability:

Near-Term Decisions

Then it could:

● Fund development of technologies in the Advanced Launch System and

other programs.

. Fund development of Liquid-fueled Rocket Boosters (LRBs).

. Fund continued development and improvement of Advanced Solid Rocket

Motors (ASRMs) and alternate turbopumps for the Space Shuttle Main

Engines.

. Fund installation of built-in test equipment in the Shuttle and more

automated test equipment in launch facilities.

● Fund the purchase of at least one additional orbiter to be delivered as soon

as possible (1996), and direct NASA to reduce the number of Shuttle flights

planned per year. NASA could reduce Shuttle flights by:

a. postponing or canceling some planned Shuttle launches; or

b. relying more on cargo-only launch vehicles, such as Titan IVs.

. Direct NASA to develop and use Shuttle-C to carry some Space Station

elements to orbit. (This would reduce the total number of flights required.)

● Continue to fund planning and technology development and test efforts

such as:

a. the Advanced Manned Launch System studies;

b. the National Aero-Space Plane program (NASP); or

c. the Advanced Launch System (ALS) program.

● Fund a program to develop a U.S. crew emergency return vehicle.

● Support joint development with Space Station partners of vehicle for

emergency return.

Far-Term Decisions

Then it could:

● Fund development of safer, more reliable launch systems to augment or

succeed the Shuttle. These might include:

a. a Personnel Launch System (PLS), or

b. an Advanced Manned Launch System (AMLS), or

c. vehicles derived from the National Aero-Space Plane (NASP) program.

. Fund development of launch vehicles or systems (e.g., ALS engines) that

could be manufactured, integrated, and launched by highly automated

methods with improved process control.

● Fund development of vehicles designed for quick turnaround, such as those

considered for an Advanced Manned Launch System or possible successors to the proposed National Aero-Space Plane test vehicle (X-30).

ix
Major Launch Systems Discussed in This Report:

Existing Systems

Delta II Expendable Launch Vehicle

Douglas, it is capable of lifting over

11,000 pounds to low Earth orbit (LEO).

Developed for the U.S. Air Force from

earlier Delta versions, the Delta II is also

available commercially from McDonnell

Douglas. Its first launch took place in

August, 1989.

Atlas II ELV---capable of lifting about

14,500 pounds to LEO. Manufactured by

General Dynamics under contract to the

Air Force, the Atlas is also available in a

commercial version from General Dynamics. Its first commercial launch is

scheduled for summer, 1990.

Titan III ELV—a commercial launch

vehicle capable of lifting up to 32,500

pounds to LEO, manufactured by Martin

Marietta. Its first commercial launch

occurred on December 31, 1989.

Titan IV ELV—manufactured by Martin Marietta under contract to the U.S.

Air Force, it is capable of lifting about

39,000 pounds to LEO. It was first

launched on June 14, 1989, and carried a

military payload.

Space Shuttle—a piloted, partially reusable launch vehicle capable of lifting

about 52,000 pounds to LEO. The Shuttle fleet now consists of three orbiters; a

fourth is being completed.

Potential Future Launch Systems

Shuttle-C-an unpiloted cargo vehicle,

derived from Shuttle systems, with a

heavy-lift capacity of up to 150,000

pounds to LEO. It would use the existing

expendable external tank and reusable

solid rocket boosters of the Shuttle, but

replace the orbiter with an expendable

cargo carrier.

Advanced Launch System (ALS)--a

totally new modular launch system under

study by the Air Force and NASA. ALS

would be capable of launching a range of

cargos at high launch rates and reduced

costs.

Crew Emergency Return Vehicle-a

vehicle that would provide for crew

escape and return from the Space Station,

independent of the Shuttle, in case of

crew medical emergencies or major Space

Station failures.

Personnel Launch System (PLS)--a

new concept for a crew-carrying vehicle

launched atop expendable launch vehicles. It would be less complex and less

expensive than the Shuttle. A PLS could

transport crew to and from space, and

might also serve as an emergency return

vehicle.

Advanced Manned Launch System

(AMLS)—an advanced successor to the

Shuttle, available after the year 2005.

System concepts vary from partially

reusable through fully reusable vehicles.

National Aero-Space Plane (NASP)

—a proposed reusable vehicle that could

be operated like an airplane from conventional runways, but fly to Earth orbit

powered by air-breathing, or air-breathing/

rocket engines. The Air Force and NASA

are working on designs for an experimental version of this vehicle, the X-30.
Contents

Page

Chapter 1. Executive Summary . . . . . . . . . . . . . . 3

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . 3

THE U.S. FUTURE IN SPACE . . . . . . . . . . . . . 3

Near-Term Space Transportation Options . . 6

Far-Term Space Transportation Options . . . 9

REDUCING SPACE TRANSPORTATION

COSTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

LIFE-CYCLE COSTS OF SPACE

TRANSPORTATION OPTIONS . . . . . . . . 14

INTERNATIONAL COMPETITION AND

COOPERATION . . . . . . . . . . . . . . . . . ● . . . . . 15

Chapter 2. Space Program Futures . . . . . . . . . 21

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 21

SPACE PROGRAM OPTIONS . . . . . . . . . . . . 21

PEOPLE IN SPACE . . . . . . . . . . . . . . . . . . . . . . 26

Chapter 3. Space Transportation Demand

and Costs ● ..*********.*****...********** 31

THE MOST ECONOMICAL OPTIONS . . . 31

Cost Estimation . . . . . . . . . . . . . . . . . . . . . . . . 35

AEROSPACE PLANES . . . . . . . . . . . . . . . . . . 37

Chapter 4. Existing Launch Systems . . . . . . . . 41

EXPENDABLE LAUNCHERS . . . . . . . . . . . . 41

THE SPACE SHUTTLE . . . . . . . . . . . . . . . . . . 41

Shortcomings of the Space Shuttle . . . . . . . 42

Options for Reducing the Risks of

Depending on the Shuttle . . . . . . . . . . . . . 43

A Shuttle Improvement Program . . . . . . . . 46

SMALL LAUNCH SYSTEMS . . . . . . . . . . . . 46

Chapter 5. Space Transportation and the

Space Station . 000...0..0.....0...000..000 53

SPACE SHUTTLE . . . . . . . . . . . . . . . . . . . . . . . 53

RESCUE OR ESCAPE VEHICLES . . . . . . . . 53

Chapter 6. Reducing Space System Costs . . . 59

SPACE TRANSPORTATION . . . . . . . . . . . . . 59

PAYLOADS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

INNOVATION AND THE U.S.

TECHNOLOGY BASE . . . . . . . . . . . . . . . . . 63

Government Programs . . . . . . . . . . . . . . . . . . 63

The Private Sector’s Role . . . . . . . . . . . . . . . 64

Chapter 7. Potential Future Launch

Systems ● . 0 . . ,0 . . . 0 . 00 . . . . . . . . . . . . . . . . . . . . 69

CARGO ONLY . . . . . . . . . . . . . . . . . . . . ......69

Shuttle-C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Advanced Launch System (ALS) . . . . . . . . 71

Unconventional Launch Systems . . . . . . . . 72

Page

CREW-CARRYING LAUNCH

SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

PERSONNEL CARRIER LAUNCHED ON

UNPILOTED LAUNCH VEHICLES . . . . 73

Advanced Manned Launch System

(AMLS) . . . . . . . . . . . . . . . . . . . . .........74

An Aerospace Plane . . . . . . . . . . . . . . . . . . . . 74

Additional Reusable Launch Concepts . . . 76

Chapter 8. International Competition and

Cooperation ● ... . . . . . . . . . . 79

COMPETITION . . . . . . . . . . . . . . . . . . . . . . . . . 79

COOPERATION . . . . . . . . . . . . . . . . . . . . . . . . . 79

Appendix A. The Sensitivity of Operational

Aerospace Plane Costs To Required

Confidence and Actual Reliability . . . . . . . . 85

Boxes

Box Page

l-A. OTA Space Transportation Publications . . 3

l-B. The Costs of Humans in Space . . . . . . . . . . 5

l-C. Coping With Launch Risks . . . . . . . . . . . . . . 7

l-D. Space Transportation and the Space

Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

l-E. Reducing Spacecraft Costs . . . . . . . . . . . . . 13

l-F. Airlines Operational Precepts . . . . . . . . . . . 13

l-G. Additional Information on Costs in

Other OTA Reports . . . . . . . . . . . . . . . . . . . . 15

2-A. Space Transportation and the Human

Exploration Initiative . . . . . . . . . . . . . . . . . . 24

3-A. Mixed Fleet Options . . . . . . . . . . . . . . . . . . . 32

3-B. Cost Components . . . . . . . . . . . . . . . . . . . . . . 34

3-C. Failure Costs . . . . . . . . . . . . . . . . . . . . . . . . . 34

4-A. U.S. Medium-Lift Expendable Launch

Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4-B. Maintaining and Improving the Current

Shuttle System . . . . . . . . . . . . . . . . . . . . . . . . 48

5-A. Escape Vehicles . . . . . . . . . . . . . . . . . . . . . . 55

6-A. The Big Dumb Booster Concept . . . . . . . . 60

6-B. Technology Development Programs . . . . 64

7-A. Potential Uses for Shuttle-C . . . . . . . . . . . . 69

7-B. The Advanced Mannned Launch

System (ALMS) . . . . . . . . . . . . . . . . . . . . . . . 75

7-C. The National Aero-Space Plane

Program (NASP) . . . . . . . . . . . . . . . . . . . . . . 75

A-A. Estimation of Reliability by Bayesian

Inference . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Figures

Figure Page

1-1. Primary Launch Vehicles of the World . . . 4

1-2. Discounted Life-Cycle Costs of Space

Transportation Options . . . . . . . . . . . . . . . . . 16

3-1. Discounted Life-Cycle Costs of Space

Transportation Options ... . . . . . . . . . . . . . 33

3-2. Sensitivity of Life-Cycle Costs to

Accounting Horizon . . . . . . . . . . . . . . . . . . . . 36

4-1. Probability of Retaining 3 or 4 Shuttle

Orbiters Over Time . . . . . . . . . . . . . . . . . . . . 45

7-1. Potential Shuttle-C Performance . . . . . . . . 70

7-2. Advanced Launch System: The ALS

Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

A-1. Probability That Test Vehicles Will

Demonstrate Acceptable Reliability If

Statistical Confidence Is Required . . . . . . 87

A-2. Expected Present Value of Mixed-Fleet

Life-Cycle Cost If Statistical Confidence

Is Required and NDV Costs Are As

Estimated by NASP JPO . . . . . . . . . . . . . . . 88

A-3. Expected Present Value of Mixed-Fleet

Life-Cycle Cost If Statistical Confidence

Is Required and NDV Costs May Be

2X NASP JPO Estimates . . . . . . . . . . . . . . 91

A-4. Probability That Test Vehicles Will

Demonstrate Acceptable Reliability

If Subjective Confidence Is Allowed . . . . 91

A-5. Expected Present Value of Mixed-Fleet

Life-Cycle Cost If Subjective Confidence

Is Allowed and NDV Costs Are As

Estimated by NASP JPO . . . . . . . . . . . . . . . 92

Figure Page

A-6. Expected Present Value of Mixed-Fleet

Life-Cycle Cost If Subjective Confidence

Is Allowed and NDV Costs May Be

2X NASP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Tables

Table Page

2-l. Maximum Lift Capability of U.S.

Launch Vehicles Using Existing

Manufacturing and Launch Facilities . . . . 22

2-2. Launch Vehicle Success Rate . . . . . . . . . . . 22

4-1. Selected Possible Improvements for

New Orbiters . . . . . . . . . . . . . . . . . . . . . . . . . . 45

4-2. A Possible Shuttle Improvement

Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6-l. Cost-Saving Technologies for Launch

Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

6-2. Cost-Reducing Strategies . . . . . . . . . . . . . . . 59

6-3. Launch System Design Strategies . . . . . . . 59

7-l. Potential ALS Technology Improvements

to Existing Systems . . . . . . . . . . . . . . . . . . . . 73

A-l. Ranges of Costs Estimated by NASP

Joint Program Office . . . . . . . . . . . . . . . . . . 89

A-2. Ranges of Costs Assumed by OTA for

Sensitivity Analysis . . . . . . . . . . . . . . . . . . . 90

xii
Chapter 1

Executive Summary

Photo credit: National Aeronautics and Space Administration

The Apollo 11 spacecraft lifts off from Kennedy Space Center atop the Saturn 5 launcher, July 16, 1969, on its way to the Moon.

Four days later the United States landed two men on the Moon. The Saturn 5 launch vehicle was capable of lifting

more than 200,000 pounds to Iow-Earth orbit.
Chapter 1

Executive Summary

INTRODUCTION

The Nation’s recovery from the space transportation crisis of 1986, which brought the U.S. launch

fleet to a standstill, is well under way. The United

States now has an operating, mixed fleet (figure l-l)

comprised of reusable Space Shuttle orbiters and

expendable launch vehicles (ELVs). The government and the private sector have invested in new

launch technologies and established a fledgling

private launch services industry. Yet concerns over

launch system reliability, operability,l capacity, and

cost remain. Over the next few years, Congress will

be faced with making critical decisions affecting the

future of U.S. space transportation systems.2 Congress’ decisions will depend directly on:

what future course the Nation wants to follow

in space; and

understanding whether existing and planned

launch systems, and their component technologies, are adequate to support the chosen direction.

This report summarizes OTA’s assessment of

advanced space transportation technologies; it was

requested by the Senate Committee on Commerce,

Science, and Transportation and the House Committee on Science, Space, and Technology. Previous

publications from this assessment (box l-A) have

examined a range of U.S. launch options, ways of

reducing launch operations costs, the “Big Dumb

Booster” concept, crew-carrying launch systems,

and spacecraft design.

The report examines the space transportation

needs of publicly supported space programs, as

executed by the National Aeronautics and Space

Administration (NASA) and the Department of

Defense (DoD). However, private sector space

activities are slowly growing in importance. Hence,

the report also explores aspects of the private

sector’s role in space transportation, both as contractor for the government’s needs and as commercial

supplier of launch services.

THE U.S. FUTURE IN SPACE

Except for the field of satellite communications,

essentially all U.S. space activities continue to be

characterized and managed by the Federal Government and supported with public funds. The Federal

Government invests in space activities in the expectation that they will serve U.S. interests by:

demonstrating international leadership in space

science, technology, and engineering;

contributing to economic growth;

enhancing national security;

supporting the pursuit of knowledge; and

promoting international cooperation in sci-

.

ence.

3

Over the years, the United States has pursued a set

of goals for its civilian and military space programs

that derive from these broad policy principles. It has

established systems in space for worldwide communications, global Earth observation, and scientific activities, including solar system exploration

probes and landers. It has also sent men and women

to work in space. Space transportation systems are

critical elements in realizing these missions.

The U.S. future course in space is uncertain,

especially in light of the tremendous political and

economic changes in progress around the world and

the strong pressures to reduce Federal spending.

Will the Government cut back on civilian and/or

Il.e., flexibility and ability to meet a schedule.

2A ~ace ~an~w~ation or launch system inc]~des tie launch vehicle, tie buildings, launch pad, ~d otier launch facilities, and the t~hnolof$es ad

methods used for launch.

sNatlona] &ronautics and Space &t of 1958, ~. i; U.S. Congress, ~fice of T~hnoJogy As~ssment, Civilian space policy ad Applicatwns,

OTA-STI-177 (Washington, DC: U.S. Government Printing Office, 1982), pp. 35-38.

-3-
4 . Access to Space: The Future of U.S. Space Transportation Systems
Chapter l-Executive Summary ● 5

Box 1-B—The Costs of Humans in Space

As experience with the Space Shuttle demonstrates, routinely placing humans in space is especially costly as

well as risky. Since 1%1, when President Kennedy called for a program to send men to the Moon and back, NASA’s

“manned” 1 space efforts have determined much of the direction and spending of the Government’s civilian space

program. In fiscal year 1990, NASA’s projects involving humans in space, primarily the existing Space Shuttle and

the planned Space Station, will consume about 70 percent of NASA’s budget for space activities.2

From the early days of the U.S. space program, experts have argued over the appropriate mix of crew and

automated civilian space activities. Although employing people in space to conduct most science research and

exploration dramatically raises the costs compared to automated approaches, the perceived national and

international benefits of having U.S. and foreign citizens live and work in space have nevertheless sustained the

human component of the civilian space program.

Existing U.S. policy calls for expanding “human presence and activity beyond Earth orbit into the solar

system."3 Pursuing this policy in earnest would eventually require markedly increased funding of the

Government% civilian activities involving people in space, and therefore additional space transportation

capability. Building a permanent base on the Moon and sending explorers to Mars, as suggested by President Bush,

would lead to substantial in-orbit infrastructure, such as a space station, orbital maneuvering vehicles, crew modules

for orbit transfer, and fuel storage depots. The pace and timing of such expansion would depend on the willingness

of Congress, on behalf of U.S. taxpayers, to support such activities in competition with other uses of public monies.

1~ W- crevv+@ttg or piloted are used in this report in lieu of “manned.”

@f the $11.92 billion appropriated for NASA’s space activities, prior to sequestration, which excludes $463 million of NASA’s 1990

budget for aeronautics, approximately $8.4 billion will be spent on projeets involving human crews.

3s~ wte House, National Space PoIicy,” Nov. 2, 1989, P.1.

SOURCE: (Mice of Technology Assessrnen t, 1990.

military space programs, or will it continue to build and military space activities, no new launch

steadily on our previous accomplishments? Alternatively, will the United States embark on sharply

expanded programs of human exploration (box l-B)

or space-based defense? This report provides a guide

to the opportunities for, and impediments to, supporting a range of goals with existing and future

launch systems. Because the lack of a clear future

course for U.S. space activities makes the scale and

character of future demand for space transportation

highly uncertain, it is not sensible to choose among

space transportation options without first selecting

the specific goals to be served. OTA concludes that

a national dialog is urgently needed to establish

the future course of the publicly supported space

program and to outline the preferred means of

accomplishing program goals.

If Congress and the Executive decide to follow

the current course of steady growth in civilian

systems4 would be needed before the first decade

of the next century to meet demand for launch of

cargo and peoples Taken together, the existing

launch fleet is capable of launching at least 900,000

pounds6 to low Earth orbit (LEO) per year, which is

about 37 percent more payload than the United

States expects to launch in 1990,7 the first year that

all of its major launch systems will be fully

operational.8 Nevertheless, new systems may be

desirable to meet specific needs, such as crew

rescue, or to reduce the dependence of the Space

Station project on the Shuttle. Even if the steady

growth in payload demand is limited to a few

percent per year, the Nation’s space transportation systems could be managed to reduce average

launch costs. The Government spends at least $5

billion per year on space transportation for civilian

needs alone. [t would be prudent to place greater

qHowever, ~dition~ Shutde orbiters or new facilities to launch eXk.t@ systems may be n~d ~ expl~ned 1ater.

sFor a 3 percent per year growth rate or less.

6~ 1992.-+- on 9 shu~le, 18 ~lta II, 4 Atl~ II, 4 Ti~n III, ~d (j Tit~ IV lalmches ~r yew, at a $)(.)-percent manifesting efflClt3nCy.

7~A awm~ !3 fjhutde, 12 Delta II, 2 Atlas H, 1 Titan HI, and 2 Titan IV flights.

8The yews of 1$)84 and 1985 were tie Imt two in which U.S. launch systems were fully operational. It Sppems Aat IW will m~k tie firs Ye~sl~

1985 that all major U.S. launch systems can be expected to operate on a sustained schedule, In addition, new private launch systems will be tested in

1990.

20-807 90 : QL 3 -- 2
6 ● Access to Space: The Future of U.S. Space Transportation Systems

emphasis on improving the reliability, operability,

and payload capacity of existing launch systems, for

example, by incorporating new technologies into

launch vehicles and launch operations procedures.

If, on the other hand, the Nation decides to invest

in a permanent lunar base, exploratory missions to

Mars, or a large-scale, space-based ballistic missile

defense, new cargo launch systems would be necessary, including a heavy-lift launcher.9 Either a lunar

base or a mission to Mars could also require new

crew-carrying launch vehicles, and would necessitate systems capable of transferring payloads and

people between orbits. New, advanced launch systems could add $10 billion to $20 billion in

development costs alone to the price tag for any

major space program initiative.l0 The timing and

scale of government investments in new space

transportation systems will depend directly on the

commitment to the goals being defined for public

space programs.

Because the Nation cannot afford to invest in all

the good ideas proposed for improved or new launch

systems, Congress and the Administration will have

to choose from among a wide range of options. Some

choices must be made in the next 2 to 3 years. Others

can wait longer. However, as argued earlier, all

space transportation decisions will depend directly on the Nation% vision for its future in

space. The following sections present options to

meet a range of near-term and far-term space futures.

Near-Term Space Transportation Options

For the coming decade, the primary space transportation issue is how to enhance U.S. access to

space by improving the reliability and operability of

existing systems—the Shuttle and ELVs. Whether

the future launch rate is high or low, higher

reliability for all launch systems (box l-C) and

improved safety and operability for the Shuttle

would increase the ability of current systems to meet

program needs. Reducing launch costs would also

reduce the impact of space transportation on the

Federal budget (for equivalent demand levels)

and might lead to more effective use of space. To

be most useful to the Nation, decisions about the

following options should be made within the next

2 to

●

●

3 years.

Fund improvements in expendable launch vehicles (ELVs). Improved assurance against program cost overruns and delays can be gained by

improving the reliability and operability of

existing ELVs, which are based on designs

originally developed in the 1950s and 1960s.

The Advanced Launch System (ALS) Program

has been studying technologies and methods to

enhance launch system operability, reliability,

and payload capacity. Incorporating the most

promising of these technologies and methods

in existing ELV systems,ll if feasible, would

improve the ELV fleet and give launch

manufacturers and operators valuable experience in using them.

Limit the Shuttle’s launch rate to a regular,

sustainable rate. Attempting to meet NASA’s

goal of 14 Shuttle launches per year12 would

increase the cumulative risk to orbiter crews,

and to space program costs and schedules.

Furthermore, because it is reusable and

carries a crew, the Shuttle is not necessarily

the most appropriate choice for launching

satellites and space probes, and for doing

many space science observations and experiments. The presence of a crew necessarily

shifts NASA’s primary concern from the mission’s scientific objectives to the safe launch

and return of its crew. Hence, additional, costly

requirements are added to the payload, and to

the mission as a whole. The Shuttle launch

schedule could be limited to a regular, sustainable rate of 8 to 10 launches per year13 by

restricting Shuttle flights to payloads requiring

human crews. NASA is already pursuing a

strategy of restricting Shuttle payloads to those

9NASA’S rment Report of the 90-Duy Smdy on Human Exploration of the Moon and Mars (Washington, DC: National Aeronautics and SPace

Administration, November 1989) states that supporting the development and operation of a lunar base and the exploration of Mars would require a space

transportation capacity of two to four times the mass that can now be delivered to orbit per year.

IOAS not~ later in ~is rew~, ~ese new launch systems might nevertheless make it possible to achieve *arPIY r~uc~ OFating costs.

1 IsOme of the~ improvements, such as fault-tolerant subsystems and ~ifici~ intelligence process controls, may ~so be appropriate for ltlC]USiOtl

in the Shuttle system.

lzAfter Orbiter E~a~~~r (OV-105) enters ~rvi~e in 1~.

lsOTA’sestimate is b~ on the n~ t. m~ntfi a rate high enough to maintain fll@t.ready launch o~ration CRWS but low eno@ to avoid stressing

those same crews. Such a rate should also allow for occasional surge to meet civilian or military needs and provide sufficent down-time to make major

changes to the orbiters as required.
Chapter l-Executive Summary . 7

Box I-C-Coping With Launch Risks

Launching payloads to orbit has always carried a high degree of risk--to people, cargo, and financiers. One

of the critical near-term needs for spare transportation will be to reduce these risks. As demonstrated by the long

standdown following the losses of Challenger and the Titan and Delta expendable launch vehicles in 1985 and 1986,

major launch failures will have a significant negative impact on public and private space activities, causing loss of

income for private companies that depend on space assets for their business, reduced effectiveness of national

security programs, and erosion of public confidence in U.S. space efforts. OTA estimates that the standdown and

recovery from Challenger alone cost U.S. taxpayers more than $15 billion.

Demonstrated success rates for U.S. launch systems, including the Shuttle, range between 85 and 97 percent,

yet U.S. plans, in both NASA and DoD, are optimistic and make little allowance for launch failures. In particular,

the heavy U.S. dependence on the Space Shuttle4 raises questions concerning the ability of the existing Shuttle

fleet to meet its allocated share of the demand for space transportation services. The Shuttle fleet has never

met projected flight rates and the existing fleet is unlikely to meet NASA% goal of 14 flights per year in the

1990s, as a result either of launch operations delays, or orbiter attrition as a result of Shuttle failures.

Attempting to meet such a high rate increases the risk to human lives, to NASA’s budget, and to other NASA

programs, especially Space Station.

The United States should expect the partial or total loss of one or more Shuttle orbiters some time in the next

decade. Public reaction to the loss of Challenger demonstrated again that there are qualitative differences between

public attitudes toward launching people and launching cargo into space. If the United States wishes to send people

into space on a routine basis, the Nation will have to come to grips with the risks of human spaceflight, Airliners

occasionally fail catastrophically but people continue to fly. The United States should exert its best efforts to ensure

flight safety and prepare itself for handling further losses that will likely occur. If the Nation perceives that the risks

are too high, it may decide to reduce the current emphasis on placing humans in space until more reliable launchers

are available.

l~e s~u~e xw~ts for more than half of the Nation’s existing payload capacity.

SOURCE: Offiee of Technology Assessment, 1990.

requiring the Shuttles’ unique capabilities. in the long run the Government could save

However, this curtailment will take several

years to execute because payloads already

designed for Shuttle launch cannot, without

excessive modification and reintegration costs,

be launched on an ELV.14 The restriction will

also cost more in the short run than launching

on the Shuttle because the Government will

have to purchase ELV launch services15 entailing substantial redesign and re-integration

costs.l6 However, if NASA can establish a

Shuttle launch rate that improves the probability of recovering the orbiter after each launch,

money and also reduce the risk to Shuttle

crews.

17

● Fund additional orbiters. Even if NASA sustains a Shuttle rate of 8 to 10 launches per year,

because of the risk of Shuttle attrition, additional orbiters may be needed just to carry out

current plans, including construction of the

planned Space Station (box l-D). The actual

reliability of the Shuttle system is unknown,

but may lie between 97 percent and 99

percent. If reliability is 98 percent, the

Nation faces a 50-50 chance of losing an

ld~e slm and/m wei@ of s~e paylo~s require them to be launched on the Shuttle. Opportunities for Titan IV to carry civilian payloads appew

to be severely limited, the result, in part, of limited production and launch facilities. Plamed DoD payloads currently fill the Titan IV manifest through

the year 2000.

IsNote hat flying payloads on ELVS would not necessarily reduce the risk of losing the payload. Demonstrated launch success rates fOr ELVS We

slightly lower than for the Shuttle. Launch services on the commercial launchers, Delta, Atlas Centaur, and Titan III, are available for NASA’s purchase.

16For exmple, he comic Ba&gro~d EXplorer (coBE) satellite, which WM OnginaJ]y schedul~ for launch on tie Shuttle, W&S redesigned tO fit

on an ELV at a cost of $30 million to 40 million. COBE was launched into a 900-kilometer polar orbit on Nov. 18, 1989, on a Delta ELV. Among other

astrophysical observations, COBE will make two total surveys of the sky of the faint background radiation that scientists believe is a remnant of the

original Big Bang, some 15 billion years ago.

17~ve10p1ng a shu~le.c Cmgo ve~cle b~~ on me shut~e system would ~so m&c II po~ib]e to off-]o~ cefiti payloads from the Shuttle (~

Shuttle-C option below).
8 ● Access to Space: The Future of U.S. Space Transportation Systems

additional orbiter in the next 34 flights (3 to

4 years). To reduce the risk of attempting to

carry out the Nation’s goals with only a

3-orbiter fleet, Congress may wish to purchase

one or more additional orbiters. A new orbiter

would cost between $2 billion and $2.5 billion,

and if ordered in fiscal year 1991, could be

ready no earlier than 1996 or 1997.

Fund a program to improve the safety and

reliability of the Shuttle. In many respects, the

Shuttle is not yet operational and can still be

improved in a variety of ways. Much like the

B-52 bomber, which has steadily grown more

capable and remained operational for over 30

years, the ability of the Shuttle orbiters to stay

in service can theoretically be extended for

another two decades. NASA is working on

technologies that could enhance Shuttle safety

and reliability as well as longevity. For example, NASA is improving the construction of the

Shuttle main engines, has begun a program to

build more reliable, higher capacity, Advanced

Solid Rocket Motors, and is installing new,

more fault-tolerant computers. A long-term,

integrated program of improvements to the

orbiter and other subsystems would be more

effective in fostering Shuttle reliability and

safety than a piecemeal program. An integrated

improvement program should also devote resources to enhancing the management of

launch operations, which would increase Shuttle’s operability and might reduce operations

costs. Congress may wish to require NASA to

prepare an integrated plan for accomplishing

these objectives.

Fund development of the Shuttle-C. For launching payloads that exceed the payload capacity

of the Shuttle and the Titan IV, the Nation will

eventually need a heavy-lift launch system. It

could build a heavy-lift cargo system in the

near term by developing a cargo launcher based

on Shuttle technology (Shuttle-C). Shuttle-C

would generally reduce the risk to the

orbiter fleet of flying large payloads. Because it would be capable of lifting heavy

payloads, Shuttle-C could also reduce the

total number of flights required to construct

Photo credit: General Dynamics Corp.

An Air Force Atlas lifting off from the launch pad.

the Space Station. In the far term, a Shuttle-C

could carry a variety of large payloads for

building a lunar base or supporting an exploratory mission to Mars. NASA asserts that

developing a Shuttle-C would cost about $1.1

billion18 and could be completed by 1995, if

started in 1991.19 Infrastructure costs, which

are included in this figure, would be minimal

because Shuttle-C would use the same launch

pads and many of the same facilities as the

Shuttle. 20 However, launch costs would be

 does not include the estimated $480 million for the first Shuttle-C launch.

 over the advisability of pursuing Shuttle-C, some that the Shuttle others 

that new systems, including Shuttle-C, should be developed.

 the Shuttle launch rate were kept at about 8 to 10 launches per year, 2 to 3 Shuttle-C launches per year could be accommodated if improvements

to existing facilities, costing about $300 million, were made.
Chapter l-Executive Summary ● 9

Box I-D-Space Transportation and the Space Station

The planned international Space Station is the largest single space project that will be undertaken in the decade

of the ‘90s. It will have to be launched in pieces and assembled in space. Current plans call for 29 Shuttle flights

to construct the station (including several logistic flights) and 5.5 flights per year to operate it. To reduce the risks

of costly delay in constructing or operating the Space Station, or concurrently meeting other NASA and DoD

missions, Congress could:

1. Fund the purchase of one or more additional orbiters for the existing Shuttle fleet, and restrict the use of

Shuttle to payloads that cannot fly on other launch vehicles.

2. Direct NASA to use ELVs or develop Shuttle-C’s for constructing and/or operating the Space Station.

3. Delay construction of the Space Station for several years and fund NASA to develop an alternative launch

system for taking crews to and from orbit. Such a spacecraft could be as simple as an Apollo-type capsule

mounted atop an expendable launch vehicle, or as complicated as an aerospace plane. If Space Station were

delayed, it would be possible to redesign the current configuration to make the best use of existing and new

transportation systems. However, as recent reactions to changes in the Space Station configuration and

schedule from our foreign partners and Congress have shown, significant additional delay in deployment of

the Space Station might cause them to withdraw their participation and Congress to curtail funding. Such

actions would significantly affect other areas.

4. Increase NASA’s budget to accommodate development of anew, more reliable crew-carrying launch system

to replace Shuttle early in the next century.

1A heavy-lift csrgo system based on Shuttie Whokogy.

SOURCE: Office of Technology Assessment, 1990.

relatively high, so the Shuttle-C would be most To assist in making such a decision, the risks

cost effective at relatively low launch rates (2-3

per year). NASA estimates each launch of a

Shuttle-C would cost over $400 million.

. Develop a crew rescue vehicle for Space

Station. Crews living and working in the

planned Space Station could be exposed to

substantial risk from major failures of the

Station. Because the Shuttle cannot respond in

a timely manner to emergencies, the United

States may need a means independent of the

Shuttle to rescue crews from the Space Station.

A rescue vehicle would add $1 billion to $2

billion in development and procurement costs

to the Space Station. Additional costs would be

incurred in developing the necessary support

infrastructure, which might include ground

operations hardware and personnel at the mission control site, landing site crews, and the

necessary subsystems and logistics support to

resupply, replenish, and repair a rescue vehicle

on orbit. To decide whether a risk-reducing

effort is worth the investment required,

Congress must be advised about how much

the investment would reduce the risk. Even

if an alternate crew return vehicle were

built, and worked as planned, it would not

eliminate all risks to station crewmembers.

and costs of building a rescue vehicle should

be weighed against the risks and costs of

other hazardous duty in the national interest. To reduce costs that would accrue to Space

Station development, it may be prudent to

cooperate with one or more of our Space

Station partners in jointly developing a crew

rescue vehicle, or adapting one of theti crewcarrying vehicles, now under development, for

the purpose.

Far-Term Space Transportation Options

Although upgrading the current fleet of ELVs and

the Shuttle would improve their operability and

might even reduce space transportation costs, new

systems will ultimately be needed if the Nation

wishes to improve the U.S. capacity to launch

payloads and crews. Emerging technologies offer

the promise of new launch systems and of

significant evolutionary improvements in existing systems during the early decades of the 21st

century. These improvements could reduce the

costs of manufacturing, logistics, and operations

while increasing reliability, operability, and performance. Developing new systems that use advanced technology would entail high cost risk and
10 ● Access to Space: The Future of U.S. Space Transportation Systems

Photo credit: National Aeronautics and Space Administration

The orbiter Atlantis lifts off from Kennedy Space Center carrying the Galileo spacecraft on the first stage of its journey toward Jupiter.

technical risk and would require a sustained technol- beginning development some 5 to 10 years before a

ogy development program. Yet new systems could system is needed.21

also bring substantial benefits to U.S. launch capa- --- . . . 

bilities. The appropriate time to start develop- Congress could fund the development of:

ment of any new system will depend on the ●

perceived future demand for space transportation services, the readiness of the technology, and

the system% cost in competition with alternative

means of performing comparable missions--

including existing launch systems. The long lead

times necessary to develop a new system and

construct necessary supporting facilities require

Advanced Launch Systems (ALS). Through the

ALS program, the Air Force and NASA seek to

develop a reliable, flexible family of mediumand high-capacity, low-cost launch vehicles to

serve government needs. They expect to capitalize on advanced materials and manufacturing and launch processing technologies, to

increase launch rate and reduce acquisition,

maintenance, and operational costs. They also

— Space Shuttle was made in and the orbiter Columbia made its in 
Chapter 1--Executive Summary ● 11

●

plan to include the ability to launch vehicles at

a higher than average rate for a short time (i.e.,

surge). A decision to proceed with ALS

development would depend on whether

there will be sufficient anticipated demand

to justify development and procurement of a

new, high capacity launcher, or whether the

value of improved efficiency in launching

currently planned payloads would justify

investing in new systems. Because it would be

significantly different in design and operation

than current launch systems, and would use a

wide variety of new technologies, development

of an operational ALS carries a significant cost

and schedule risk.22

The ALS program has been funded almost

entirely by DoD, which has decided not to

pursue development of the ALS at this time;

DoD plans to continue technology development of propulsion and other crucial enabling

technologies. If ALS technology development

continues to be funded by Congress and the

Executive, the DoD could be in a position to

start full development of the ALS in the mid or

late 1990s, if necessary.

A Personnel Launch System (PLS) or Advanced

Manned Launch System (AMLS). Even if

NASA makes substantial improvements to

the Shuttle, eventually a replacement will be

needed if the United States decides to continue its commitment to maintaining crews

in space. A decision to replace the Shuttle

should be based on the age and condition of the

Shuttle fleet and the estimated benefits to be

gained from developing a new crew-carrying

launch system. NASA is exploring the technologies, systems, and costs required for development of two new launch systems. Although

concepts for the two proposed systems overlap,

their general focus is different. PLS designers

are considering several concepts, ranging from

ballistic entry vehicles to a small “spaceplane. ” A PLS vehicle would carry very little

cargo and could be launched atop a large

expendable booster. AMLS designs favor a

reusable vehicle larger than the PLS, but

smaller and easier to refurbish and launch than

the Shuttle, and capable of carrying both crew

●

and cargo (about 20,000 pounds). An AMLS

might be launched by a reusable booster.

A PLS could be developed and tested sooner

than an AMLS and might be needed to backup

or replace the Shuttle. Developing and operating a PLS would likely costless than an AMLS.

If it entered the fleet before the Shuttle is

retired, a PLS could assist in providing more

reliable access to space for humans. In addition,

a version of the PLS vehicle might serve as a

Space Station crew escape vehicle. The choice

between an AMLS and a PLS will depend on

cost and the need for an alternative to the

Shuttle.

An Aerospace Plane. Developing a fully reusable piloted vehicle that could be operated like

an airplane from conventional runways, but fly

to Earth orbit powered by a single propulsion

stage, as envisaged for the National AeroSpace Plane (NASP), would provide a radically

different approach to space launch and a major

step in U.S. launch capability. If successful, an

aerospace plane could provide increased flexibility and reduced launch costs. NASA and the

Air Force are jointly developing the technology

base that could lead to an X-30 experimental

aerospace plane, which would incorporate advanced air-breathing propulsion as well as

rocket propulsion. Developing a successful

X-30 test vehicle may cost more than $5

billion.23 Proponents argue that benefits to U.S.

industry and U.S. competitiveness may more

than repay that investment.

Until an X-30 flies successfully to orbit and

back, estimated costs for building an operational vehicle based on technology demonstrated in the X-30 will remain highly uncertain. At the present time, the Air Force has

shown the greatest interest in an operational

aerospace plane, primarily because it would

provide quick response to emergencies and fast

turnaround in preparation for reflight. While

very attractive from an operational point of

view, building such a vehicle poses large

technological and cost risks. Either a PLS or

AMLS could be developed sooner than an

aerospace plane based on X-30 technology.

Other proposed launch systems, including

22AS ~otcd ~wller, reducing launch costs by means of ALS or any other new Iaunc h syslcnl May require incre~ payload demand.

zqThe NASP ~ogm Office estimates X.30 ~osls for two [es~ vehicles and suppor~lv~ illfr~s~~ture at $3 billion to $5 billion. OTA regards thtXe

estimates as a lower limit.
12 ● Access to Space: The Future of U.S. Space Transportation Systems

●

small launch systems and the ALS, may

provide stiff economic competition to an

aerospace plane, because they may also

serve DoD needs for launching most payloads quickly at much lower investment cost.

Other Advanced Concepts. NASA and DoD are

funding studies of a variety of highly advanced

launch concepts, including all-rocket, singlestage-to-orbit vehicles, laser propulsion, and

chemical ram accelerator techniques. Although

each of these concepts has strong proponents,

each will also need considerable additional

study before its costs and benefits will be

sufficiently understood to determine whether or

not it is an appropriate candidate for development. Nevertheless, research on advanced concepts and related technologies could eventually

lead to a cost-effective future launch system

and will be of broad importance in maintaining

U.S. innovation in launch technologies. For

example, previous studies of single-stage-toorbit vehicles have cast doubt on their ability to

perform efficiently because the necessary lightweight, high-strength materials were not available. However, recent advances in the development of the necessary advanced materials in the

NASP program suggest that single-stage-toorbit rocket-propelled vehicles may yet prove

feasible.

REDUCING SPACE

TRANSPORTATION COSTS

Reducing launch costs and improving operability are the two most important issues to

address as the Nation considers the development

of any new launch systems. Launching payloads to

low Earth orbit on existing launch systems costs

from $3,000 to $10,000 per pound. Placing them in

geosynchronous orbit can cost up to $20,000 per

pound. Thus, reducing launch costs will play a

critical role in making space activities more affordable and productive. It is especially important in this

era when there are strong pressures to reduce Federal

budget deficits. Making launch systems more flexible and more capable of meeting a schedule could

also contribute to reduced operating costs. However,

the costs of designing and procuring spacecraft are

often much higher, per pound, than launch costs.

Attention should also be given to decreasing spacecraft costs (box l-E).

NASA, the Air Force, and the private sector have

been working on methods of reducing both nonrecurring and recurring launch costs. For example,

new manufacturing and construction methods could

lower the cost of building new launch vehicles. Yet,

because launch and mission operations may

constitute a sizable fraction of the cost of launching payloads into orbit,24 system designers and

policy makers must give greater attention to

launch operations and support and to how

launch vehicle and payload designs interact. For

many aspects of launch operations, the broad operational experience of the airlines and some of the

methods they employ to maintain efficiency may

provide a useful model for space operations (box

1-F). However, even if the launch systems are

designed for reduced operational costs, it will be

difficult to improve operations and support without

making significant changes to the institutions currently responsible for those operations.25

Harnessing industry’s innovative power in a

more competitive environment could lead to

reduced launch costs and more effective use of

U.S. resources for outer space. By promoting

private sector innovation toward improvements in

the design, manufacture, and operations of launch

systems, the Government could reduce the cost of

Government launches, yet relatively few incentives

to involve private firms exist today. Current U.S.

space policy, which directs NASA, and encourages

DoD, to purchase launch services rather than launch

vehicles from private firms is a promising first

step.

26 Yet, despite the fact that both agencies are

moving toward purchasing launch services, change

zdne cost of o~rations range from 15 to 45 percent of launch costs, depending on the complexity of operations. For example, operations cosw for

the Atlas or Delta ELV are about 15 percent of launch costs; operations costs of the Space Shuttle, which also include costs of flight operations as well

as launch operations, because the orbiter is reusable and piloted, reach at least 45 percent of the total. See U.S. Congress, Office of Technology

Assessment, Reducing Launch Operations Costs: Nm Technologies and Practices, OTA-TM-KC-28 (Washington, DC: U.S. Government Printing

Office, September 1988), p. 13.

zSRed~ing Lunch operations Costs: New Technologies and Practices, op. cit., footnote21. Adapting airline practices, which have been develop

over several decades of experience, and based on millions of hours of flight time, will take considerable imagination and innovation.

26wfhen he Government p~ch~s la~ch sy5tem5, it mu5t m~n~n a l~ge st~f to o~rate tie launchem, or to over= con~act~s who do SO. By

purchasing launch services, the Government gives up most of the responsibility (and therefore cost) for overseeing details of launch manufacture and

operation.
Chapter 1--Executive Summary ● 13

Box 1-E—Reducing Spacecraft Costs

Although reducing the costs of space transportation is extremely important in bringing down the costs of

exploring and exploiting outer space, reducing payload costs, especially for DoD satellites, is also vitally important.

For these payloads, launch costs are typically only a small percentage of the total costs of a program, because the

costs of designing and building spacecraft are extremely high. NASA and DoD spacecraft typically cost between

$160,000 and $650,000 per pound.l For commercial satellite launches to geosynchronous orbit, where spacecraft

costs and launch costs are comparable, reducing both is important. Price competition between fiber optics cable

systems and satellite communications systems for the highly competitive Atlantic and Pacific routes make the

reduction of overall program costs especially important to communications satellite companies.

Spacecraft costs can be reduced by innovative design:

● allowing them to be much heavier so expensive weight reduction techniques are not needed (fatsats);2

• making them very light and limiting them to fewer tasks (lightsats);

● building very small spacecraft (microspacecraft) that could be launched like cannon shells for specialized

tasks.

Each of these approaches would impose different requirements on launch systems. Congress may wish to order

a comprehensive study of these and other innovative approaches to spacecraft design.

llltese estimates include amortized spacecraft program ~Sts.

2~~~m ~chiev~ h= ~PW t. ~ ~l~ve~y ~~1 cmpw~ to ~over~] CCM of ~ payload and launch service, U.S. C~~S,

Mice of Technology Assessment, Afiortkble Spacecraft: Design and Launch Alternatives, OTA-BP-ISC-60 (Washington, DC: U.S.

Government Riming Office, hnuary 1990), pp. 12-16.

SOURCE: Office of Technology Assessment, 1990.

Box 1-F—Airlines operational Precepts

. Involve operations personnel in design changes.

. Develop detailed operations cost estimation

models.

● Stand down to trace and repair failures only when

the evidence points to a major generic failure.

● Design for fault tolerance.

. Design for maintainability.

. Encourage competitive pricing.

. Maintain strong training programs.

. Use automatic built-in checkout of subsystems

between flights.

SOURCE: office of Technology Assessment, 1990.

is relatively slow, in part because NASA and DoD

managers are reluctant to cede greater control over

the fate of extremely expensive payloads to the

private sector.27

Low-cost space transportation options that are

designed to achieve minimum cost rather than

maximum performance28 may merit further study,

particularly if their development meshes with other

space transportation efforts such as those to develop

a liquid rocket booster for the Shuttle, or new

engines for the ALS.

One way to stimulate the private sector’s innovative creativity would be to issue a request for

proposal for ALS-type launch services and have

industry bid for providing them. Such an approach

assumes minimum government oversight over the

design and manufacturing processes. It would also

require the aerospace community to assume much

greater financial risk than it has taken on in the past.

Another option that might lead to lower launch

costs would be for the government to issue space

transportation vouchers to space scientists whose

experiments are being supported by the government.29 These vouchers could be redeemed for

transportation on any appropriate U.S. launch vehicle, and would free scientists to choose the vehicle

they thought most suitable to the needs of the

27B~ce I), Berkowitz, “Energizing the Space Launch Indusy,” Issues in Science & Twhmdogy, Winter 1989-90, pp. 77-83.

28UOS. conWess, Office of Technoloa Assessment, Blg D& Boosters A ~UI.~’<>St, Space Tra~port~ion Optwn?--#ackgrouti paper

(Washington, DC: International Security and Commerce Program, 1989).

29MOIIY Macauley, “hunch Vouchers for Space Science Research,” Space Polic), vol. 5, No. 4, Pp. 311-320.
14 . Access to Space: The Future of U.S. Space Transportation Systems

spacecraft. This policy would free space scientists

from dependence on the Shuttle, and might increase

opportunities for researchers to reach space.

The small launch vehicle concepts being developed by the private sector in response to the Defense

Advanced Research Projects Agency’s Advanced

Satellite Technology Program (“lightsats”) promise

another avenue for cost reductions. They provide the

means for small payloads to reach orbit for a

relatively low cost per launch.30 In this case, the

Government provided a market sufficiently large to

induce private firms to develop the vehicles using

private funding.31

LIFE-CYCLE COSTS OF SPACE

TRANSPORTATION OPTIONS

Estimates of life-cycle costs, which include the

nonrecurring costs required to develop and build a

new launch system as well as future recurring

procurement and operating costs, provide the best

economic measure of the worth of a new investment

compared to other possible options. The overall cost

of Earth-to-orbit transportation over the next three

decades will include, at minimum, the costs of

launching vehicles of existing types, at least until

they are superseded. Almost certainly, some vehicles will fail catastrophically, leading to direct,

indirect, and intangible costs. If the Government

elects to launch at higher rates, additional facilities

will be needed to prepare and launch vehicles.

If the Government elects to develop and use new

types of launch vehicles, U.S. taxpayers must fund

their development, production, and operation, as

well as construction or modification of the facilities

that would be needed to launch them. Nextgeneration vehicles will also incur some risk of

failure, although how much cannot now be estimated

with confidence. Nevertheless, investment in developing new types of vehicles could yield later payoffs

in performance, operability, and safety, as well as

lower cost of operation and risk of failure, compared

to current vehicles.

To decide whether proposed investments in improving the Nation’s Earth-to-orbit transportation

system could be justified on economic grounds by

predicted savings in the out-years, OTA estimated

the life-cycle cost of each of several alternatives.32

The life-cycle cost includes costs of developing new

types of launch vehicles (if any), purchasing reusable elements of launch vehicles, building any

additional launch facilities required, launch operations (including purchase of expendable launch

vehicle elements), expected costs of launch vehicle

failures, and the risk of cost overrun (“cost risk”).

OTA considered only expenditures that would be

incurred between 1989 and 2020.33 OTA calculated

the present value of the estimated life-cycle cost by

discounting future expenditures to reflect the lower

opportunity cost of obligating a future dollar,

relative to spending a dollar now.

Figure 1-2 presents OTA’s estimates of the

present value of life-cycle cost of each of six

alternative vehicle mixes for each of three space

transportation demand scenarios. The ranking of

alternatives according to present value of life-cycle

cost, and the net benefit of each alternative relative

to continued use of current vehicles, depends on the

demand for space transportation. The differences in

life-cycle cost are small in the low-growth demand

scenario, especially when compared to the uncertainty represented by cost risk. However, the cost

estimates clearly favor the Advanced Launch System in the expanded demand scenario, which includes low-growth demand plus rapidly increasing

demand for launches of heavy cargo, such as

formerly contemplated for deployment of a Phase 1

Strategic Defense System (SDS). Options for a lunar

base or a Mars expedition could result in demand

analogous to the expanded demand scenario. Alternatives for a lunar base and Mars expedition are

currently being weighed by the National Space

Council, NASA, and others. The DoD continues to

assess options for development and deployment of

SDS.

q~or many SMaII launch systems, the cost to launch a pound of payload is relatively high. Nevertheless, small systems may provide a cost-effective

launch for owners of small payloads who would otherwise have to launch their payload m a secondary payload on a multiple-payload launch into a less

optimum orbit.

311fiti~ fli~~ of @bi~ Sciences COrp. Pegasus, an air-launched vehicle capable of (arrying 600 to 900 pounds into low Hmbit, wc sch~ul~

for spring 1%X).

qzFor addition~ details on space transportation costs, X% box I-G.

330TA ~li~le co~ldence in Projwtlons of demand to or beyond 2020,” but chose 20’20” as an accounting horizon to Capture most Of the discounted

out-year savings (5 percent real discount rate) from vehicles that would not be operational until about 2005,
Chapter 1--Executive Summary ● 15

Box 1-G--Additional Information on Costs in Other OTA Reports

. Launch Options for the Future describes in greater detail the mission models and launch system options OTA

considered and the methods OTA used to estimate the life-cycle costs quoted in this report.

● Reducing Launch Operation Costs discusses criteria used for comparing space transportation options, and

confidence bounds on launch vehicle reliabilities.

● Big Dumb Boosters assesses proposals for designing unmanned, expendable launch vehicles to minimize cost. Ž Round Trip to Orbit discusses additional options for piloted launch vehicles, and uncertainties in estimates of

Shuttle reliability, on which expected Shuttle failure costs depend sensitively.

• Affordable Spacecraft discusses payload costs, assesses proposals for reducing them, and discusses their effects

on demand for space transportation.

SOURCE: OfRce of Teehrtology Assessment, 1990.

INTERNATIONAL COMPETITION because most launch technology has direct military

AND COOPERATION applications. In addition, before other countries had

developed indigenous capabilities, the United States

This decade has seen the rise of intergovernmental

competition in space transportation (figure 1-1). The

Soviet Union, Europe, Japan, and China operate

launch systems capable of reaching space with

sizable payloads. A number of experts have raised

doubts about the capability of the U.S. private sector

to compete for launch services in the world market,

especially in the face of a relatively small market for

commercial launch services and competition from

some foreign companies, which receive greater

government subsidy than do U.S. firms. The U.S.

was pleased to have them depend on us for launch

services. If launch demand does not increase markedly by the turn of the century, and the U.S. supply

of launch vehicles remains sufficient, there may be

little reason to change the U.S. stance toward

cooperation in space transportation. However, if the

Nation wishes to expand its activities in space, the

costs of space endeavors would quickly reach the

level where a much greater degree of international

cooperation, including cooperation in space transportation, could be highly desirable.

Government could assist the U.S. private sector

by negotiating with the governments of other As it debates the direction and magnitude of

nations to ensure a competitive environment for the space program, Congress will have to decide,

launch services in which prices and other eco- as a matter of policy, how much of our publicly

nomic factors reflect the true costs of providing supported space program we want to pursue

those services. Alternatively, the U.S. Government alone and how much we wish to involve foreign

could assist U.S. industry to the same degree and in partners. International cooperation lessens our abila similar manner as other nations assist their own ity to use space to demonstrate national technologilaunch services industry. The U.S. Government also cal prowess, but can place the United States in a

has a stake in reducing its own costs for space position to help guide the direction of global space

transportation. It could therefore provide modest development. Cooperation could also reduce the

finding to encourage private sector innovation for cost to the United States of a particular project,

streamlining the manufacturing and launch opera- though it would generally increase the project’s total

tions processes and improving productivity. cost. However, for potential foreign partners to

join with the United States in such projects, the

Although the United States has always main- United States will have to demonstrate that it not

tained a vigorous program of international coopera- only has the willingness to cooperate on major

tion in space in order to support U.S. political and projects but the institutional mechanisms to

economic goals, it has cooperated very little with follow through. Our partners’ recent experience

other countries in space transportation, in large part with the United States on Space Station34 and on

Sdsome E~Opean and Japanese delegates to tie 40th Congress of the International Astronautical Federation, October 1989, expressed considerable

dissatisfaction with U.S. actions in Space Station development and worried that the [Jnited States was beeoming an unreliable partner.

3SJeffrey M. ~norovitz, “EIMope Delays Soho SpacWraft Work Until U.S. Approves Joint ProJect MOU,’’Avian”on W’eekandSpace Technology, NOV.

13, 1989. See U.S. Congress, Office of Technology Assessment, Intematwnal Cooperation und Competition in Civilian Space Activities (Washington,

DC: U,S. Government Printing Office, 1985), for a general discussion of U.S. cooperative +greements, mechanisms, and problems.
16 ● Access to Space: The Future of U.S. Space Transportation systems

● 0 0 ● ● ● I

I I I I 1 I I I

‘i

,,
Chapter 1--Executive Summary ● 17

science missions35 may diminish their interest in

pursuing cooperative projects with the United

States.

Potential areas for cooperation in space transportation include:

● The use of European and Japanese vehicles to

supply Space Station. The European Space

Agency has developed a capable launch system

(Ariane IV) and is now developing a much

more powerful Ariane V. Either vehicle could

be used to supply the Space Station. Japan is

developing its H 11 launch system, which will

be roughly comparable to the existing Ariane

IV. The United States could benefit by

sharing responsibility for resupply of the

Space Station with its international partners.

●

●

Cooperation with the Soviet Union, Europe,

and Japan in space rescue. The Soviet Union

is presently the only country beyond the United

States with the capability to launch people into

space. However, as noted, Europe and Japan are

working on crew-carrying systems. Agreements on docking standards, and procedures for

space rescue, could increase astronaut safety

for all nations and lead to more extensive

cooperative activities in the future. Initial

meetings have been scheduled to discuss the

nature and extent of such cooperation. Both this

cooperative project and the use of foreign

vehicles to supply the Space Station have the

advantage that they risk transferring very little

U.S. technology to other participants. ●

Joint development of a crew rescue vehicle for

the Space Station. The United States could be

even more innovative in cooperating with other

countries. For instance, as noted earlier, it may

decide to provide an emergency crew escape or

return vehicle for the Space Station. If properly

redesigned and outfitted, the European spaceplane, Hermes, might be used as an emergency return vehicle late in this century. Early

in the next century, the planned Japanese

HOPE spaceplane might also serve that same

purpose.36 However, such international cooperPhoto credit: Japanese National Space Develepment Agency

A Japanese Mu-3S-3 solid rocket launches the

interplanetary probe SUISEI toward Halley’s

comet in 1985.

ation would also require a degree of international coordination and technology sharing for

which the United States has little precedent.

Joint development of an aerospace plane. With

strong encouragement from their private sectors, Germany, Japan, and the United Kingdom

are working separately toward development of

aerospace planes. The level of foreign sophistication in certain areas of advanced materials,

advanced propulsion, and aerodynamic computation is on a par with U.S. work. A joint

development program with one or more of

these partners might allow the United States to

achieve an aerospace plane faster and with

lower cost to the United States than the United

States could on its own. Although a joint

 Technology, 

13, 1989. See U.S. Congress, Office of Technology Assessment, Cooperation and Competition in Civilian Space Activities (Washington,

DC: U.S. Government Printing Office, 1985), for a general discussion of U.S. cooperative agreements, mechanisms, and problems.

 interested s@@ area, it may 

feasible to redesign HOPE for the purpose.
18 ● Access to Space: The Future of U.S. Space Transportation Systems

●

project would risk some technology transfer, if

properly structured, such a joint project could

be to the mutual benefit of all countries

involved.

U.S. use of the U.S.S.R. Energia heavy-lift

launch vehicle. The U.S.S.R. has offered informally to make its Energia heavy-lift launch

vehicle available to the United States for

launching large payloads. As noted throughout

this report, the United States has no existing

heavy-lift capability. Thus, the Soviet offer

could assist in developing U.S. plans to launch

large, heavy payloads, such as fuel or or other

non-critical components of a Moon or Mars

expedition. Concerns about the transfer of

militarily useful technology to the Soviet

Union would inhibit U.S. use of Energia for

high-technology payloads. As well, NASA

would be understandably reluctant to propose

use of a Soviet launcher because such use might

be seen as sufficient reason for the United

States to defer development of its own heavylift vehicle.

Chapter 2

Space Program Futures

INTRODUCTION

As the result of long-term constraints on the

Federal budget, the Nation can pursue only a few of

the many good space transportation concepts that are

proposed today. Until the Nation chooses what it

wants to accomplish in space, and what the U.S.

taxpayer is willing to pay for, neither the type nor

number of necessary launchers and facilities can

be estimated with accuracy. Possible driving

forces behind additional space transportation capabilities to support publicly funded space activities

include the Space Station, space-based ballistic

missile defense, a permanent lunar base, and landing

people on Mars. Some have suggested that more

modest Government expenditures are appropriate,

especially in the face of pressing domestic needs,

until we have reduced our current budget deficit and

reversed our foreign trade imbalance. Congress, the

Administration, and the American people as a whole

are faced today with making choices among these or

other, alternative options for the U.S. future in space.

The tremendous economic and political changes

now taking place in the Soviet Union, Eastern and

Western Europe, the Pacific Rim nations, indeed in

the entire world, suggest that charting a course will

be fraught with considerable uncertainty about the

future, and the United States’ place in the world

economy. It will be important to weigh the future

course of our Government’s space activities in the

context of these uncertainties. A failure to debate

these choices vigorously and to select among them

decisively will nevertheless result in some sort of

national space program, but one that may not serve

the long-term political and economic interests of the

United States as well as a carefully considered

policy.

This chapter focuses on the broad implications for

space transportation of following specific space

program futures; they were chosen by OTA to span

the range of policy options open to the United States.

Later chapters present launch technologies and

systems and assess their economic and technological

implications for the future of U.S. space activities.

SPACE PROGRAM OPTIONS

The choice among policy options such as those

summarized below will determine the demand, and

hence costs, for U.S. space transportation. The

options are not necessarily exclusive; for example,

Options 2 and 4 could be pursued at the same time.

Option 1: Continue Existing NASA and DoD

Space Programs.

This option assumes that NASA would continue

with its current plans to build the planned Space

Station and launch several large space-based observatories and robotic planetary spacecraft by the end

of the century. It also assumes that no DoD or NASA

spacecraft would weigh more than current launch

vehicles could lift.

The United States possesses a capable fleet of

launch vehicles and the facilities necessary to

meet current launch demands and provide for

limited near-term growth. By 1992, the year the

Shuttle orbiter Endeavour comes on line, planned

space transportation capability (table 2-1) would be

sufficient to lift about 900,000 pounds of payload

into low Earth orbit (LEO)l per year, assuming there

are no major delays or failures.

2 By comparison, in

1984 and 1985, the last years all U.S. launch systems

were full y operational, the United States launched an

average of about 600,000 pounds into orbit.

Launching 900,000 pounds to LEO each year

would cost the Nation about $7 billion per year for

transportation alone, assuming no major failures

occur.

3 However, as the launch failures of 1985,

1986, and 1987 illustrate,4 space transportation is

risky. No launch vehicle is 100 percent reliable;

launch success rate, which is an indicator of

reliability, varies from 85 to 97 percent (table

2-2). If space transportation capacity is limited to

ITo a reference orbit 110 nautical miles high, inclined to 28.5” from the equitorkd plane.

ZTO reach 890,~0 pounds Wr yem the United States wottld have to launch payloads equivalent to 9 Space Shuttle flights, 6 Titan IVS, 4 Titan IIIs,

5 Titan 11s, 4 Atlas 11s, 12 Delta 11s, and 12 Scouts.

3nis estimate, in fiscal yew 1989 dollars, includes the expected costs of operations and failures, but no amortized nonrecurring coSts or COSt tisk.

4BetwWn Novem&r 1985 and Mmch 1987, tie United States had lost two Titan 1115, One Delta, One At]as Centaur, the Orbiter Chuflenger, and their

payloads as a result of technical or human failures. Loss of Chdenger also resulted m a loss of seven crewmembers. These failures, and the recovery

from them, cost the United States an estimated$16 to $18 billion. Arianespace, the French launch company, also sustained a launch failure of an Ariane

3 in May 1986, which cost insurers, Arianespace, and the European Space Agency well over $100 million.

-2l –
22 ● Access to Space: The Future of U.S. Space Transportation Systems

Table 2-l-Maximum Lift Capability of U.S. Launch Vehicles Using Existing Manufacturing and Launch Facilities

Launch vehicle Mass delivered Production rateb

Launch ratec Capability d

scout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570 12

Titan II . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,500 5

Delta H (3920) . . . . . . . . . . . . . . . . . . . . . . 7,600 12

Atlas/Centaur. . . . . . . . . . . . . . . . . . . . . . 13,500 5

Titan Ill . . . . . . . . . . . . . . . . . . . . . . . . . . . 27,600 10

Titan IV . . . . . . . . . . . . . . . . . . . . . . . . . . . 39,000 6

Space Shuttle . . . . . . . . . . . . . . . . . . . . . 52,000” n.a.f

Total . . . . . . . . . . . . . . . . . . . . . . . . . . .

x90 percent manifesting efficiencyg =890,000 pounds

18 6,840

5 27,500

18 91,200

4 54,000

4 110,400

6 234,000

9 486,460

992,400 pounds

aPounds deliveredtoallOnm circular orbit at 28.5° inclination, unless otherwise noted.

%kximums ustainabieproductionratewithcurrentfacilities,mvehicles peryear

CM~irnurn Sustainable launch rate with current facilities, in vehicles per year.

dMW delivered X the lessor of the maximum production rate or the maximum launch @f3

&fhlS figure is ~ averqe of the three existing ofiiters’ p-formance to a 110 nm circular orbit (C)VI 02: 45,600 ~unds; OVI 03 and C)vl 04:49,100 pounds).

f~t ~Wlica~e sin~ the orb~er is reusable. No orbiter production is currently planned beyond the Cha@n9er rePla~ment.

gVehicles often fly carrying less than their full capacity. Manifesting efficiency is the amount of lift capability that is actually used by payloads or upper stages.

Volume constraints, scheduling incompatlbilihes, or security considerations often account for payload bays being less than full by weight.

SOURCE: Office of Technology Assessment, 1990.

Table 2-2-Launch Vehicle Success Rate

Percentage successful

Launch vehicle Total launches . Overall Last 20 attempts

Scout . . . . . . . . . . . . . . . . . . . . . . . 112 88 95

Delta* . . . . . . . . . . . . . . . . . . . . . . 182 93 95

Atlas Centaur** . . . . . . . . . . . . . . . 66 85 85

Titan . . . . . . . . . . . . . . . . . . . . . . . . 145 95 85

Shuttle . . . . . . . . . . . . . . . . . . . . . . 33 97 95

:~oes not include flights of Delta Il.

Does not Include flights of Atlas Il.

SOURCE: National Aeronautics and Space Administration & U.S. Air Force.

Lower Confidence Bounds on Reliability for 95 Percent Confidence (in percentage)*

Launch vehicle Based on all launches Based on last 20 launches

Scout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Delta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Atlas Centaur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Titan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shuttle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

- Exact, nonrandomized, one-sided lower confidenea bounds.

SOURCE: Offim of Technology Assessment, 1990.

vehicles currently in the fleet and on order, the

United States runs a significant risk that some

planned missions—most notably the Space Station-could be delayed, disrupted, or lost because of technical difficulties or accidents. If such

risks are deemed too high, additional space

transportation capacity may be needed before the

end of the century just to carry out current

plans.5 Near-term additional capacity could be

provided by one or more additional Shuttle

orbiters or a Shuttle-C.

82 78

89 78

76 66

91 66

86 78

Even if growth of the Nation’s space programs is

moderate (less than 3 percent per year in terms of

total mass lifted to low Earth orbit), it would be

prudent to continue to improve the reliability and

capacity of current systems by incorporating new

technologies into launch vehicles and launch operations. A continuing program to make such improvements to systems and facilities could cost a billion

dollars per year. In addition, the United States

may need a means independent of the Shuttle for

returning crews from the Space Station in case of

sNote, however, that p~chasing extra space (ranspo~ation capacity carnies a certain cofl risk If the extra Capacity were not needed, tie ex~nditmes

would have been wasted.
Chapter 2-Space Program Futures ● 23

emergency. A crew emergency return vehicle and

the facilities to support it would add between $1

billion and $2 billion in development costs to

NASA’s space transportation budget over the next

decade, plus an unknown amount of operating costs.

Option 2: Limit growth of NASA’s activities for

humans in space.

This option would defer beginning construction

of the Space Station until the early part of the 21st

century and place greater near-term emphasis on

space science and robotic planetary exploration. It

would require only six to eight Shuttle flights per

year and reduce NASA’s need for a heavy-lift launch

vehicle such as Shuttle-C.

Limiting Space Shuttle flights to eight per year

would reduce space transportation costs for 1989-

2010 by about $10 billion, compared to space

transportation costs for OTA’s Option 1, in which

the Shuttle flight rate would increase to 12 per year

by 2005.6 Probably, even more would be saved on

other NASA accounts, because 65 to 70 percent of

NASA’s budget goes to support space activities

involving people in space—a fraction that will

increase as Space Station funding grows.

The United States possesses the technology to

improve the capabilities of existing launch vehicles

and facilities through evolutionary modifications.

Even if overall space transportation demand fell well

below U.S. capability, the incremental improvement of current vehicles and facilities could

provide a low-cost means to enhance U.S. launch

capabilities. Evolutionary improvements will be

most effective if they are guided by a long-term

plan that includes both a concrete goal and the

steps to reach it.

Option 3: Establish a lunar base or send crews to

Mars.

On the 20th anniversary of the Apollo Moon

landing, President Bush announced his intention to

support “a sustained program of manned exploration of the solar system and the permanent settlement of space.”7 His vision includes the construction

of the Space Station during the 1990s and the

establishment of a permanent lunar base, as well as

human exploration of Mars sometime in the next

century (box 2-A).

A long-term program of this magnitude would

require building new heavy-lift cargo systems, such

as the Shuttle-C or the Advanced Launch System

now under study, or even larger ones,8 and would

require new crew-carrying systems. It would also

need orbital maneuvering vehicles and reusable

orbital transfer vehicles.9 In addition to scientific

instrumentation, crew accommodations, and propulsion units, cargo would consist of large amounts of

fuel and supplies to support both Moon or Mars

crews and the necessary Earth-orbit infrastructure. 10

Such a program would continue the strong dominance of government in the development and

deployment of space infrastructure and require

considerable growth in the U.S. budget for the

civilian space program.

Option 4: Continue the trends of launching

increasingly heavier payloads and/or pursue

an aggressive Strategic Defense Initiative

(SDI) test program.

The size and weight of spacecraft for communications, navigation, reconnaissance, and weather observations have been increasing slowly and have

been forcing the lift capacity of launch systems up

with them. An aggressive SDI test program would

also require vehicles of greater weight capacity than

we now possess.

Although it would be feasible to expand the lift

capacity of current launch systems to meet such

growth in payload weight, if demand is high, new,

advanced systems may be more reliable and costeffective. This option would require moderate

growth in the Nation’s capacity to launch payloads.

6u.S. congeSS, Office of Technoloa Assessment, ~unch Optiow for t~ Future A Buyer’s G~i&, OTA-ISC-383 (Washington, DC: U.S.

Government Printing Office, July 1988). However, the average cost per launch would increase somewhat.

Tfiesident G~rge Bush, sp~h at the Smithsonian Institution’s National Air and Space Museum, j~Y 2Q 1989.

gNati~na] ~ronautics and Space Admlnis~ation, Report of the 90. Day SW on H~n E~loration of the Moon and Mars (Washington, DC:

November 1989), sec. 5.

9A orblt~ maneuvcfig Vehlc.e is designed t. move payloads wound in Space Within a Single orbit. An orbit~ ~ansfer vehicle would tGUMfer

pay]oads from one orbit to another, e.g., from low-Earth transfer orbit to geosynchronous orbit.

Iq.e., orbit~ maneuvering and orbital transfer vehicles, and other suppmting elements
24 ● Access to Space: The Future of U.S. Space Transportation Systems

Box 2-A--Space Transportation and the Human Exploration Initiative

On July 20, 1989, 20 years after man first set foot on the Moon, President Bush announced

his intention to support “a sustained program of manned exploration of the solar system and the

permenent settlement of Space.”1

In particular, the President suggested establishing a permanent

base on the Moon after the turn of the century and exploring Mars sometime later. The President’s

initiative follows through on a recommendation first made to President Nixon by the Space Task

Group in 1969,2 and reexamined in the 1986 report of the National Commission on space,3 and

in NASA’s “Ride” report of 1987.4

Shortly afterward, NASA began a 90-day study to frame alternative strategies for

accomplishing these goals. NASA’s report starts with the assumption that “reliable access to

space will be provided through a mixed fleet of launch vehicles that includes the Space Shuttle,

existing expendable launch vehicles, and planned heavy-lift launch vehicles.”5 It also assumes

that the Space Station will serve as an orbital space transportation node.

The transportation needs of the Human Exploration Initiative would be substantial. NASA

estimates that in order to establish the lunar outpost, it would need a vehicle having a lift capacity

of about 60 metric tons (132,000 pounds), capable of launching a payload 7.6 meters in diameter

and 27.4 meters long. With three Space Shuttle Main Engines, the proposed Shuttle-C could carry

such a payload. NASA estimates total payload mass per year necessary to support contstruction

and operation of the lunar outpost would equal 110 to 200 metric tons, depending on whether or

not the lunar transfer vehicle is reusable, and whether those missions carry cargo and crews, or

cargo only. About three Shuttle-C flights would be sufficient to accomplish this task.

For the Mars mission, NASA estimates it would need a vehicle capable of lifting 140 metric

tons (308,000 pounds). This large heavy lift vehicle is about 50 percent larger than any vehicle

yet proposed for the ALS program and about twice as large as the largest Shuttle-C NASA has

contemplated. Building such a vehicle would require a new development effort, including

development of high-thrust liquid engines. Yearly masses delivered to orbit to support the Mars

mission are estimated to range between 550 and 850 metric tons (1,210,000 to l,870,000 pounds)

depending on mission type and the place in the overall mission schedule.

According to NASA, the existing ELV fleet, with a few enhancements, could support “all

the robotic lunar and Mars missions that are required before the human missions begin.”6

However, some of these missions might be made cheaper or simpler if a heavy-lift vehicle were

already available. For heavy-lift capacity prior to the end of the century, NASA expects to use

its planned Shuttle-C. After that, larger, cheaper vehicles would be required to carry out the

Human Exploration Initiative.

Other groups, including the Aerospace Industries Association, and the American Institute

of Aeronautics and Astronautics, are exploring space transportation and other requirements for

the initiative. For example, a group working at Lawrence Livermore National Laboratory has

suggested that the mass requirements for a Mars mission might be vastly smaller than NASA has

proposed. 7 As these and other interested groups develop their proposals, space transportation

requirements will be an essential part of planning for a return to the Moon or the exploration of

Mars.

l~~ant Garge Bu&,s-h at the Smi-ian Institution’s National Air md SpaC~ Mu*u, jlllY ~s 1989.

2Space T&k Group, The poM-Ap@J SPace Program: Directions for the Funue. SeP~bM ~9@s

~Natio~ m~wion on Space, pioneering the Space l+ontier (New York, NY: B~m -s,May 1986).

%ally K, Ride, Leadership and America’s Future in Space, a report to the Administrator {Washington, DC:

National Aeronautics and Space Administration, August 1987).

5Natio~ Aeronautics and Space Adrttinistration, Report of the !XM@ Sttuiy on Hturwn EX@@on of tie ~Q~R

and Mars, p. 5-1.

61bid., p. 54.

7 ~wU W~, “me Gwat Explora~ion: Assuring Amcnican Leaderhsip in Manned Exploration Of tk SOkW

System,” briefing presented to the National Space Council, Nov. 29, 1989.
Chapter 2--Space Program Futures ● 25

Option 5: Develop the capability to launch

small-and intermediate-size payloads quickly

and efficiently to support DoD needs.

DoD space policy calls for the development of a

launch system, or systems, to launch satellites at

substantially reduced costs with increased responsiveness, capability, reliability, availability, maintainability, and flexibility, plus the ability to operate

in peace, crisis, and war. The Air Force Space

Command (AFSPACECOM) has stated that to

perform its mission, primarily the operation of

satellites, it would need the ability to schedule a

launch within 30 days, change out payloads on 5

days’ notice, and launch 7 satellites in 5 days.

AFSPACECOM noted that “the DoD’s inability to

provide launch support at heightened conflict levels

has been highlighted by both policy emphasis on

warfighting capability and by the constriction of

DoD’s launch capability caused by recent Space

Shuttle and expendable launch vehicle groundings.”11 The proposed Advanced Launch System

(ALS), with its family of launch vehicles, could help

meet the requirement for responsiveness—at least in

peacetime. ALS is also being designed for a‘ ‘surge’

rate higher than average in order to recover from a

backlog or to respond in crisis.

It may be impractical to assure launch support in

wartime, 12 but if such support proves practical, it

would probably require additional launch systems to

complement the ALS. For example, the National

Aero-Space Plane (NASP) Program is examining

the potential for building a highly responsive launch

system that could fly to orbit with a single propulsion stage from a conventional runway. If the

experimental X-30 that would be built in this

program proves successful, it might lead to operational vehicles that are more responsive than an ALS

and potentially as survivable as, say, SR-71 aircraft.

Small, transportable rockets, such as the Pegasus

or Taurus, *3 could provide a survivable, responsive

capability to launch payloads, such as “lightsats”14

much sooner, but neither they nor operational

aerospace planes could launch the largest satellites

that have been proposed. U.S. Space Command is

currently conducting an Assured Mission Support

Space Architecture study to evaluate the potential

role of lightsats and survivable launch.

Option 6: Deploy a full-scale space-based ballistic

missile defense system and/or dramatically

increase the number and kind of other military

space activities.

Deployment of a full-scale, space-based missile

defense 15 would require large cargo vehicles that are

relatively inexpensive to launch. In 1988, the Air

Force Space Command stated that:

. . . deployment of a [SDI] Strategic Defense System. . will require payload capability and launch

rates beyond the capacity of present systems.

. . . even if available, such lift capability and launch

rates would not be affordable at today’s launch

cost .16

This remains true in 1990. The Administration has

not yet decided on the form a Strategic Defense

System would take, but AFSPACECOM established

its requirements for ALS payload capability per

launch (220,000 pounds17) and per year (over 5

million pounds) to accommodate the numerous

payloads that a Phase I Strategic Defense System

might require and the very heavy payloads that a

Phase II Strategic Defense System might require.l8

A Phase I Strategic Defense System, by itself, might

llAir Force space (lxntmnd, AFSPACECOM Statement of Operational Need (SON) 003-88 for an Advanced Launch System (AU), Aug. 1Z3 1988.

lzThe Ah Force Space command rmq@zeS mat a wartime launch capability is not the only means of providing wartime mission caP*ilitY;

alternatives include proliferation, hardening, or defense of satellites, or reliance on terrestrial systems. None of these, including wartime launch, can

assure capability to perform all missions in wartime; see U.S. Congress, Office of Technology Assessment, Anti-Satellite Weapons, Countermeasures,

and Arms Control, OTA-ISC-281 (Washington, DC: U.S. Government Printing Office, 1985).

13c& lakr swtjon (ch. 4) entitled s~fl ~~h SySte~. pegmus is being designed to la~ch up to ~pounds to a 110 nautic~ mile orbit inckled

to 28”. Taurus should carry up to 3,000 pounds to a similar orbit.

14$= us, Congss, ~fjce of Twho]ogy Assessment, Afforalztde Spacecrqt&Design and Launch Alternatives, OTA-Bp-ISC-m (wuh@90n!

DC: U.S. Government Printing Office, January 1990), ch. 4.

IsUnder Cment plans, tie f~l-sc~e, space-b~ ballistic missile defen~ s~c~re would ody & Udetien in _II of &PIOymtXlt.

IGAir Force Space Command, Op. cit., footnote 11.

17$ Fifically, AFSPACECOM rqulres la~ch of l@,ooo-Pmd paylo~s to pol~ orbit; a rocket that co~d do that ~ld &O launch zoo,~ &O

220,000 pounds to a low-inclination, low-attitude orbit.

l~or exaples, SW U.S. Congess, Office of Twhnology Assessment, SD1: Technology, Survivabilio, and Sofwme, OTA-ISC-353 (w~~~on~

DC: U.S. Government Printing Office, June 1988), pp. 148-153.
26 ● Access to Space: The Future of U.S. Space Transportation Systems

require much less capacity,19 especially if a limited

system intended primarily for protection from a few

accidental launches is deployed. Current U.S. launch

systems can launch only about 52,000 pounds per

launch and 890,000 pounds per year.20

In some form or another, each of these alternatives has been championed by one or more

advocates. Choosing among them and following

through with the necessary funding will require

political and economic consensus on the part of

the American people and continued, focused

attention from Congress and the Administration.

Meeting the space transportation needs of specific

programs is only part of the reason for making

changes to the current launch systems. Other, more

qualitative, goals serve to guide policy choices, and

may be even more important in setting the Nation’s

agenda in space. For example, Congress may wish to

find the development of critical new capabilities or

improvements to the quality of space transportation,

or Congress may wish to ensure that funding serves

abroad national objective of maintaining leadership

in space activities.

PEOPLE IN SPACE

One of the distinguishing characteristics of the

U.S. civilian space program is its emphasis on

activities by people in space, to demonstrate U.S.

leadership in the development and application of

high technology. Since the early days of the Apollo

program, the “manned” space efforts of the National Aeronautics and Space Administration

(NASA) have served as a major driver of the

direction and spending of its space activities. Today,

NASA’s projects involving people in space, primarily the Space Shuttle and Space Station programs,

consume about 70 percent of NASA’s budget.

Critics of NASA’s emphasis on humans in space,

especially individuals in the space science community, have questioned the wisdom of continuing to

emphasize these activities because of the heavy

explicit and implicit demands they place on the

civilian space budget.21 In particular, critics note that

using the Shuttle to launch the Hubble Space

Telescope and large solar system probes, like

Galileo and Ulysses, subjects space science to

unnecessary reliance on the Shuttle’s ability to meet

a launch schedule, and exposes the crews to unnecessary danger. Costs for launching such payloads are

generally higher on the Shuttle than with ELVs.

These critics point out that Europe and Japan, while

spending considerably less on space than the United

States, have nevertheless achieved noteworthy scientific and technological results. However, supporters of maintaining the human presence in space

argue that such activities provide essential visibility

for the U.S. space program and underscore America’s international technological leadership:

The [reamed] space[flight] program is a visible

symbol of U.S. world leadership; its challenges and

accomplishments motivate scientific and technical

excellence among U.S. students; and it provides for

a diverse American population a sense of common

national accomplishment and shared pride in American achievement.22

Current administration space policy calls for

demonstrating U.S. leadership by expanding

“human presence and activity beyond Earth orbit

into the solar system, ’ and developing “the Space

Station to achieve permanently manned operational

capability by the mid-1990s.”23 This policy directs

NASA to improve the Space Shuttle system and start

the Space Station by the mid-1990s. It also directs

NASA to establish sustainable Shuttle flight rates

for use in planning and budgeting Government space

programs, and to pursue appropriate enhancements

to Shuttle operational capabilities, upper stages, and

systems for deploying, servicing, and retrieving

spacecraft as national requirements are defined.24

Recently, President Bush announced his intentions

to complete the Space Station before the end of the

century, establish a permanent Lunar base at the

lgIn U.S. con~ess, office of Technology Assessment, Luunch Options for fhe Future: A Buyer’s Guide, OTA-ISC-383 (Washington, DC: U.S.

Government Printing Office, July 1988), OTA assumed that 50 Titan IV launches per year, in addition to launches for other missions, would suffice to

deploy and maintain a representative Strategic Defense System. This corresponds to 2 million pounds per year.

Zqbid., p. 3, table 2-1.

zlRobe~ L, ptik, ‘‘~efica’s $30 Billion pie in tie Sky,” w~~”ngton post, Jan. z 1, 1990, p. B3; Robefl Bless, “space Science: What’s WrOng at

NASA,’’lssues in Science and Technology, winter 1988-89, pp. 67-73; Bruce Murray, C’Civilian Space: In Search of presidential Goals, ’’Issues in Science

and Technology, spring 1986, pp. 25-37.

zzJohn M. ~gsdon, “A sustainable Rationale for Manned Space Flight,” Space Poffcy, VO1. .5, 1989, PP. 3-6.

23The white House, office of the Press Secretary, “National Space Policy,” NOV. ~. 1989.

zdIbid.
Chapter 2-Space Program Futures ● 27

beginning of the next century, and later send crews

to explore Mars.25

Achieving each of these goals would be expensive. In the Apollo era, the Nation had the welldefined political goal of landing a man on the Moon

within a decade and returning him safely, a goal that

carried the rest of the space program and a large

budget commitment with it. If the budget for space

activities were unlimited and if the needs of the

various space interests could all be met equally well,

then many space program goals might be usefully

pursued at the same time. However, as a result of the

current budgetary stringency, and many demands on

the Federal budget, Congress must choose among

competing ideas for the United States to demonstrate

its leadership, rather than attempting to demonstrate

leadership across the board as it once did.26

In contrast to U.S. civilian activities, the military

space program has spent relatively little on crews in

space, despite numerous efforts over the years by

some to identify military missions that would

require crews. Indeed, DoD has recently reaffirmed

that it has no requirements for crews in space,

although the Air Force has articulated requirements

for piloted aerospace vehicles. Production of a

piloted aerospace plane for military use, such as is

contemplated for a follow-on to the current National

Aero-Space Plane Program, would reverse DoD’s

historical stance.

Expanded commitment to crews in space, as

contemplated by NASA and the Air Force, would

require increasing budgetary outlays and require the

development of new crew-carrying space vehicles.

These systems would be costly to develop, but might

return their investment over time if operational costs

can be kept extremely low.

To illustrate the problem Congress faces, the

Space Shuttle system and the Space Station, both of

which require crews, dominate NASA’s budget for

the 1990s.27 As noted in a 1988 Congressional

Budget Office report, simply to maintain NASA’s

‘‘core program,’ which includes these major programs, but no large additional ones, will require

NASA’s overall budget to grow from $10.5 billion

in fiscal year 1989 to about $14.4 billion in fiscal

year 1995. 28 NASA plans to spend about $2.5 billion

per year for investment in its space transportation

system, including improvements to the Shuttle, an

advanced solid rocket motor, and in-orbit transportation vehicles. Operating the Shuttle will cost at least

$2.0 billion per year. Anything new, such as an

additional orbiter beyond OV-105, major modifications to the Shuttle, a Shuttle-C, a Personnel Launch

System, or an emergency crew return vehicle, will

add to these costs.

Spaceflight is inherently risky. As noted in a

previous section, the exact reliability of the Shuttle

system is uncertain, but experts estimate that it lies

between 97 and 99 percent. Therefore, the United

States may expect to lose or severely damage one or

more orbiters within the next decade, perhaps with

loss of life. One of the major challenges for the U.S.

civilian space program will be to learn how to

reconcile America’s goals for the expansion of

human presence in space with this potential for loss

of life. In particular, if the United States wishes to

send people into space on a routine basis, the

Nation will have to accept the risks these activities

entail. If such risks are perceived to be too high,

the Nation may wish to reduce its emphasis on

placing humans in space.

zS’’Rem~ksby the president at tie Twentieti Anniversmy of Apollo Moon Landing,” The White House, Office of the Press %eretary, JUIY 20, 1989.

26u.s. Congess, Office of Technology Assessment, Civilian Space Policy and Apphcutions, OTA-STI-177 (Washington, DC: U.S. Government

Printing Office, June 1982), ch, 3,

zTMos[of ~esiden[ Bush ’sr~uested20Wrcentbudget increase for NASA in fiscal yea 1990 derived from increases to build the SpaCe Station, which

is now scheduled for completion in 1999.

2~.s. Conwess, Congesslonal Budget office, The ~A,$A ,Drogr~ in f~e ]990s uti ~eyo~ (washin~on, DC: May 1988), pp. X-XIV.
Chapter 3

Space Transportation

Demand and Costs

The Titan IV launch vehicle lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station.

This launcher will be the workhorse launcher for the Air Force for at least the next decade.
Chapter 3

Space Transportation Demand and Costs

Projections of demand for U.S. transportation to

and from low Earth orbit vary from about 600,000

pounds to more than 4 million pounds of payload per

year. The lower projections are based on an assumption that the tonnage launched annually will grow

slowly for the next two decades. The higher projections are based on an assumption that the United

States will undertake an ambitious space initiative,

such as deployment of a space-based missile defense

system, establishment of a manned base on the

Moon, or a manned expedition to Mars. Because

there is no broad consensus on the desirability of

these proposals and on the willingness to pay for

them (nor even on how much they would cost),

post-1995 demand for U.S. space transportation is

highly uncertain.] This uncertainty makes rational

choice among options for improving the Nation’s

space transportation systems extremely difficult.

Nevertheless, failing to choose an alternative now

could leave the United States incapable of meeting

future needs, or paying for excess capacity.

In the face of such uncertainty, OTA analyzed the

space transportation needs for three scenarios (called

mission models) for growth of demand:

Low-Growth: launch rate grows about 3 percent per year to 41 launches per year by 2010,

then remains constant through 2020.

Growth: launch rate grows about 5 percent per

year to 55 launches per year by 2010, then

remains constant through 2020.

Expanded: launch rate grows about 7 percent

per year to 91 launches per year by 2010, then

remains constant through 2020.2

These mission models represent, respectively, the

approximate demand that would likely result from

efforts to:

— maintain the existing course of NASA and

DoD space programs (option 1),3

—

—

deploy the Space Station in the mid-1990s

while expanding the NASA science program and continuing the trend of launching

heavier military satellites (options 4 or 5),

or

send humans to Mars and establish a base

on the Moon, or deploy a layered ballisticmissile-defense system in orbit (options 3

or 6).

The mission models differ only in demand for

heavy-cargo launches; they are identical in postulated demand for light-cargo launches and piloted

missions. By largely ignoring the weights, sizes, and

destinations of individual payloads, these simplified

mission models help focus OTA’s broad-brush

analysis on the sensitivity of costs to gross demand.4

OTA calculated the life-cycle cost of servicing the

demand postulated by each mission model with each

of five different combinations of types (“fleets” of

launch vehicles—box 3-A).5 Although intangible

benefits such as “space leadership” may be

weighed in comparing the options, the most appropriate economic yardstick is life-cycle cost (box

3-B), discounted to reflect the opportunity cost to the

Nation of diverting funds from competing demands

on the Federal budget.

THE MOST ECONOMICAL

OPTIONS

Figure 3-1 shows OTA’s estimate of the discounted life-cycle cost of each of five space transportation options in each of the three OTA mission

models. Estimated life-cycle costs increase with

increasing demand, even though cost per pound of

payload (not shown) would decrease with increasing

demand.

l~tim~es of dem~d tJUOUgh 1995 Me relatively accurate, because the lead time for payload development is so long.

z~s~ably, Government demand for space transportation would depend on space transportation costs, but there have been few effo~ to forecmt

the price elasticity of demand for space transportation. For two examples, see DoD and NASA, Nan”onal Space Transportatwn and Support Study

2995-2010, Annex B: Civil Needs Data Base, Version 1.1, Volume I-Summary Report, Mar. 16, 1986, pp. 3-31,3-32; and Gordon R. Woodcock,

“Economics on the Space Frontier: Can We Afford It?” SS1 Update (f%inceton, NJ: Space Studies Institute, May/June 1987).

30ption 2 would fit within this scenario, but would save about $10 billion by reducing the total mass of payload launched to orbit.

4A more de~il~ an~ysls would exalne tie sizes ad weights of ex~t~ pay]oads and match ~em Up M* ex~td launch vehicles. However,

in most cases, pursuing such a detailed analysis for periods beyond 5 or 10 years would yield no additional insight, as the characteristics of payloads

that far in the future are extremely poorly known.

5SW alW U.S. Congess, office of T~.o\o~ Assessment, Launch optiom for the Future A fJuyer’~ Guide, OTA-ISC-383 (Washington, DC: U.S.

Government Printing Office, July 1988), table 1-1.

-31-
32 ● Access to Space: The Future of U.S. Space Transportation Systems

Box 3-A--Mixed Fleet Options

In the future, as in the past, the United States will probably want to perform such a variety of

missions in space that a variety of types of launch vehicles—a “mixed fleet’ ’-will be needed, for

operational flexibility if not economy. The current mixed fleet includes the Scout, Delta, Atlas, and

Titan launchers (including several versions of each), as well as the Shuttle and a few new, small,

privately developed launch vehicles such as the Conestoga and Pegasus. In the near future, most

payloads will be carried by the Titan, Shuttle, and Medium Launch Vehicles (the Medium Launch

Vehicle is derived from the Delta, and the Medium Launch Vehicle II from the Atlas).

To estimate whether improving these launch systems, or developing a new one would be

economical, OTA has estimated and compared the life-cycle costs of servicing postulated Government

demand with each of five different mixed fleets. OTA considered using one of the mixed fleets in two

different ways; hence a total of six mixed-fleet options were considered (see figure 3-1). Although most

options were named after the new system under consideration, or the primary cargo vehicle (e.g., Titan

IV), a mixed fleet of crewed and unmanned launch vehicles would be used in each option:

. Titan IV: Continue to use Titan IVS for heavy cargo, Delta II and/or Atlas-Centaur II Medium

Launch Vehicles for light cargo, and Space Shuttles for round-trip missions (manned launches

or return of cargo to Earth).

● Enhanced Baseline: Immediately begin upgrading Titan IVs and Space Shuttles to increase

reliability and reduce cost. Meanwhile, use Titan IVs for heavy cargo, Delta II or Atlas-Centaur

II Medium Launch Vehicles for light cargo, and Space Shuttles for round-trip missions.

● Low-rate Shuttle-C: Immediately begin developing Shuttle-C expendable, unmanned, heavycargo launch vehicles. In 1995, begin launching three per year to carry some cargo that would

otherwise be launched on Titan IVs, Medium Launch Vehicles, and Space Shuttles. Continue

to use Titan IVs, Medium Launch Vehicles, and Space Shuttles for the remaining missions,

. High-rate Shuttle-C: Immediately begin developing expendable, unmanned, Shuttle-C heavycargo launch vehicles. In 1995, begin launching them at whatever rate is required to replace

Titan IVs. They would also carry some cargo that would otherwise be launched on Medium

Launch Vehicles and Space Shuttles. Continue to use Medium Launch Vehicles and Space

Shuttles for the remaining missions.

● Advanced Launch System: Begin developing unmanned Advanced Launch System (ALS)

vehicles and facilities in time for them to supersede Titan IVs in 2005, They would also carry

some cargo that would otherwise be launched on Medium Launch Vehicles and Space Shuttles.

Continue to use Medium Launch Vehicles and Space Shuttles for the remaining missions.

• Advanced Manned Launch System: Begin developing Advanced Manned Launch System

(AMLS) vehicles and facilities in time for them to supersede Space Shuttles in 2005. Continue

to use Titan IVs and Medium Launch Vehicles for one-way missions.

Small launch vehicles-such as the Scout Conestoga, and Pegasus-are expected to carry a small

fraction of total Government payload and contribute a small fraction of total launch cost. They were not

explicitly included in the mixed-fleet options for this reason, not because of any judgment that they

would be uneconomical for selected missions.

SOURCE: Office of Technology Assessment, 1990.
Chapter 3-Space Transportation Demand and Costs • 33
34 ● Access to Space: The Future of U.S. Space Transportation Systems

Box 3-B--Cost Components

Life-cycle cost-appropriately discounted to reflect risk and opportunity cost—is the most important

economic criterion by which to compare different launch vehicle architectures. For each mission model examined

here, the option that has the lowest discounted life-cycle cost would be must economical, if the assumed discount

rate were appropriate and if the required funding were available. However, the most economical launch architecture

might be deemed unaffodable if it would require more spending in a particular year than the Executive would

budget or than Congress would authorize and appropriate for the purpose.

Life-cycle costs include both nonrecurring and recurring costs. The nonrecurring costs include costs of design,

development testing, and evaluation (DDT&E), production of reusable vehicle systems, and construction and

equipping of facilities. The recurring costs include all costs of planned operations, including production of

expendable vehicle systems, as well as expected costs of failures. In general, early nonrecurring investment is

required to reduce total discounted life-cycle cost.

Failure cost, a component of life-cycle cost, deserves special mention because: 1) it can be as great as the

balance of life-cycle cost, 2) it is sometimes excluded from cost estimates, and 3) it is random-hence

uncertain-and depends sensitively on the reliabilities of the launch vehicles used. These reliabilities are themselves

very uncertain--even for vehicles that have been launched more than a hundred times, and especially for vehicles

that have never been launched. Expected costs of failures are calculated from estimates of vehicle reliabilities and

estimates of the costs that would be incurred in the event of a failure (see box 3-C).

Cost risk is included in the cost estimates quoted here. Cost risk was defined in the Space Transportation

Architecture Study (STAS) as a subjectively estimated percentage increase in life-cycle cost (discounted at 5

percent) that the estimator expects would be exceeded with a probability of 30 percent, assuming certain ground

rules are met. Basically, cost risk is intended to represent likely increases in life-cycle cost caused by unforeseen

circumstances such as difficulties in technology development or facility construction. However, cost risk as defined

in the STAS does not include risks of cost growth due to mission cancellations, funding stretch-outs, or standdowns

after failure, which were excluded by the ground rules of the study. The cost risk estimates by OTA also exclude

risks of mission cancellations, funding stretch-outs, and standdowns after failures; estimation of these risks in a

logically consistent manner will require more sophisticated methods than were used here, or in the STAS. However,

OTA’s cost risk estimates do include the risk of greater-than-expected failure costs.

SOURCE: Qffke of Technology Assessment, 1990.

Box 3-C-Failure Costs

The cost of failures makes a substantial contribution to understanding the life-cycle costs of a launch system

relative to any other. A system with a high purchase cost may nevertheless be cheaper in the long run than a

lower-cost system if the former exhibits much higher reliability. Even if both reliability and acquisition costs are

equivalent the life-cycle costs could be very different if one system requires a much longer standdown for analyzing

and correcting a failure than another.

The expected cost of failures of launch vehicles are calculated by multiplying the number of launches planned

by the estimated probability of failure on a single launch (one minus the estimated reliability), then multiplying the

result by the estimated cost per failure. Cost per failure will generally include cost of accident investigation and

corrective action. It may also include costs of replacing and reflying lost payloads, replacing reusable vehicle

components, and delays pending completion of accident investigation.

In the Space Transportation Architecture Study (STAS), operations costs were estimated assuming that

operations would be continuous (i.e., no “standdowns”), and failure costs were estimated assuming that all lost

payloads would be replaced and reflown. The same assumptions were made in this report. Accident investigation

costs were included, but launch operations were not assumed to be suspended pending their completion. To assume

that a fleet would stand down pending completion of accident investigation requires that the opportunity costs of

delaying missions be estimated. Moreover, because some missions would be canceled as a result of the delay,

life-cycle costs would have to exclude missions not flown.

SOURCE: Offb of Technology Assessment, 1990.
Chapter 3--Space Transportation Demand and Costs ● 35

If facilities and fleets are sized for demand

appropriate to the Low Growth scenario, all of the

options OTA considered would have comparable

life-cycle costs. The estimates of expected life-cycle

costs of different options differ by only a few percent

of the estimated uncertainties (“cost risk”) in those

estimates. Moreover, the theoretically most economical choice depends on the accounting horizon

assumed (i.e., the last year for which estimated

recurring costs are cumulated). Building an Advanced Launch System (ALS) to supersede Titan

IVs is most economical for the nominal accounting

horizon (2020), but improving current vehicles7

would be most economical if the accounting horizon

were instead 2010 (see figure 3-2).

The probability that building an ALS would be

most economical increases with increasing demand.

In the Expanded demand scenario, the ALS is

estimated to yield savings (relative to continued use

of Titan IVs) comparable to the estimated cost risk

of the ALs option.

If demand for cargo flights were as in the

Low-Growth mission model but crew-carrying

flights were limited to 8 per year (policy option 2),

all mixed-fleet options would cost between $9

billion and $10 billion less than indicated in figure

3-1 for the Low-Growth mission model, except that

the AMLS option would cost about $7 billion less.

Thus demand for launch services is the most

important determinant of the economic value of

investing in new launch systems. An ALS is likely

to be most economical at high launch rates, but if,

instead, demand grows slowly above current launch

rates, all of the options OTA considered would have

comparable life-cycle costs. The reader is cautioned that current methods of estimating launch

system costs are subjective and unreliable, and

that large development projects for new space

transportation systems are not likely to achieve

their cost or technical objectives without continuity in commitment and funding.

The costs of options that include operational

aerospace planes are highly uncertain and should be

estimated by methods designed specifically to account for such uncertainties (see below).

Cost Estimation

OTA derived the estimates in figure 3-1 using the

methods described in Launch Options for the

Future. 8 The nominal cost-estimating relationships

were used, but those for Shuttle-C, the ALS, and the

AMLS have been revised.

OTA now assumes Shuttle-C development will

cost $985 million, in fiscal year 1988 dollars.l0 A

Shuttle-C could be launched with two or three

engines; if it carries no more payload than a

two-engine Shuttle-C could carry, a three-engine

Shuttle-C could tolerate a failure of one of its Space

Shuttle Main Engines (SSMEs) and hence could be

more reliable than a two-engine Shuttle-C. OTA’s

cost estimates are for a three-engine Shuttle-C,

which NASA estimates would cost $424 million per

launch, if launched with engines that have been used

one time on a Shuttle flight.11 NASA has not

estimated the reliability of a three-engine ShuttleC;12 OTA’s cost estimates are based on an assumed

reliability of 97 percent. 13 NASA estimates a first

launch could be attempted 54 months after authority

to proceed (with development) is granted;14 OTA

assumes operational launches will begin in 1995.

6CongeSS pr~~bit~ development of the Transition (or Interim Advanced) Launch System; see 101 Stat. 10CC.

7The Shutde, Titan IVS, and Delta IIs or Atlas-Centaur Ils.

Su.s. con~ess, office of Technology Assessment, op. cit., footnote 5. Launch Optkms for the Future contained some errors, most notably:(1) The

inadvertent use of Design, Development, Testing and Evaluation (DDT&E) cost for the cost of procuring reusable hardware led to overestimation of

the costs of the Transition, ALS, and Shuttle options. The magnitude of the errors in life-cycle cost estimates was smaller than the estimated uncertainty;

correcting them did not change the rank of the most economical option for each mission mode~. OTA is indebted to Mitch Weatherly of General Dynamics

Space Systems Division for pointing out anomalies that led to OTA’s discovery of this error. (2) The statement on p. 40 that “Shuttle-C would pay for

itself after being used for Space Station deployment alone” is incorrect; cf. box 7-3 on p. 69: “Shuttle-C . . . cotdd provide useful flexibility . . . at a small

premium in life-cycle cost.”

g~id., table A- 1, P.82.

1%1,1 14,3 million in fiscal yew 1991 dollars-Jack Walker, MSFC, facsimile transmission, Jan. 11, 1990.

11$479.5 million in fiscal year 1991 dollars-ibid.

12M Gabfis, NASA I-IQ, Code MD, personal communication, Jan. 17, 19%.

13’’Shu~]efihutde-C OWra[lons, Risks, and Cost Analyses,” LSYS-88-~8 (E] Segllndo, CA: L Systems, Inc., J~y z 1, 1988), postulated a reliability

t.xxween 97.5 and 98.9 percent, with 98 percent the “average.” OTA multiplied this “engineering estimate” by 99 percent to account for the unreliability

of humans and other unmodeled systems and processes. See U.S. Congress, Office of Technology Assessment, footnote 5, p. 85.

ldm Ga~s, NASA HQ, Code MD, personal communication, Jan. 17, 1990.
36 ● Access to Space: The Future of U.S. Space Transportation Systems

Figure 3-2-Sensitivity of Life-Cycle Costs to Accounting Horizon

Discounted life-cycle cost (FY89$)

$400B --

$350B

$300B

$250B

$200B

I

I

. “

I

Options

. Titan IV

. Enhanced Baseline

I Shuttle-C (low-rate)

Shuttle-C (high-rate)

Advanced Launch System (ALS)

Advanced Manned Launch System (AMLS)

1

2018 2019 2020

Discounted life-cycle cost (FY89$)

$400B t

$350B .

OTA now assumes ALS development

$7.3 billion (in fiscal year 1988 dollars),

1 2018 2019 2020

will cost

facilities

(including one pad) will cost $3.9 billion plus $150

million times the peak annual ALS launch rate in

excess of 25 per year, operations will cost $70

million per launch (of which about $17 million will

be for the expendable launch vehicle), and the

“engineering estimate’ of reliability on ascent is

98.4 percent.l5 The estimates of recurring cost per

launch and reliability are for a liquid-fueled version

of the proposed ALS expendable launch vehicle at a

rate of 10 per year.l6

$ 150B +

$ 10OB L Expanded mission model

$50B

$OB 1

1– 1

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Horizon

OTA assumes Advanced Manned Launch System

(AMLS) costs will be as estimated for the proposed

Shuttle II described in Launch Options for the

Future but now assumes AMLS will begin operating

in 2005. NASA is considering several alternative

concepts as follow-ons to the Shuttle, including the

AMLS and Personnel Launch System (PLS) .17

NASA has awarded Rockwell International a contract to flesh out several alternatives, estimate their

costs, and help weed out the less promising ones.

The estimates in figure 3-1 include costs incurred

from 1989 to 2020. In Launch Options for the

lsThe MS Joint I-YOgMIII Office estimates hat operation could begin in 1998, but a recurring cost of $70 million per launch would not be achieved

until 2005.

lbAs before, and as for o~er launch vehicles, OTA assumes the operational reliability on ascent will be 99 percent of the engineering estimate of

reliability, and the operational reliability on return, given successful ascent, will be 99 percent.

17s= ch. 7. For a more det~]~ description of these alternatives, see: U.S. Congress, Office of Technology Assessment, Round Trip ‘b Orbit: Human

Spaceflight AlternativeMpecial Report, OTA-ISC-419 (Washington, DC: U.S. Government Printing Office, August 1989), pp. 53-56.
Chapter 3-Space Transportation Demand and Costs ● 37

Future, OTA did not accumulate recurring costs

after 2010, because demand after 2010 is highly

uncertain. However, not accumulating costs beyond

2010 might unfairly penalize options that include

advanced systems, because it allows only 5 years for

the annual savings expected from an ALS or AMLS

to pay back the substantial initial investment that

would be required to reduce annual costs. Hence it

is also instructive to compare life-cycle costs over a

longer life cycle. Figure 3-2 shows the life-cycle

costs of the same options for accounting horizons

ranging from 2010 to 2020, and shows that extending the accounting horizon did not significantly

affect the ranking of the options: all are roughly

comparable at Low-Growth launch rates, while an

ALS is estimated to be significantly less costly than

the other options at Expanded launch rates.

AEROSPACE PLANES

OTA has considered an option for developing and

using aerospace planes incorporating NASP technology to supersede the Shuttle and complement

Titan IVs. Aerospace planes, if successful, could be

operated with greater responsiveness, flexibility,

and economy than could rocket-powered launch

vehicles.

However, it is not yet possible to estimate the

life-cycle cost of such an option in the conventional

manner, which depends on extrapolating or interpolating curves showing how subsystem costs depend

on design parameters, such as subsystem weight.

Similar curves are obtained for the costs of operational procedures as functions of labor and equipment requirements. Such curves are obtained by

fitting a curve of a given type---g.,., a line—to

points representing the costs and weights (etc.) of

technologically similar subsystems that have been

built and the costs of which are known.18 However,

the experimental X-30 and operational vehicles

derived from NASP technology, which would use

air-breathing engines for propulsion most or all of

the way to orbit, would have systems so unlike any

previously developed that no data points exist to

which cost curves for key systems, such as engines,

could be fit. Further, the feasibility of such aerospace

planes remains unproven. Hence subjective engineering judgment must play a greater role than usual

in estimating the costs of operational vehicles.

Moreover, the reusability of operational vehicles

would make the average cost per flight extremely

sensitive to parameters such as maintenance manhours per sortie and the probability of catastrophic

failure, both of which OTA regards as extremely

uncertain. These quantities were underestimated in

the case of the Space Shuttle, the orbiter of which

was designed for 100 flights. This led to underestimation of average cost per flight. As currently

envisioned, operational aerospace planes would be

designed to last 500 flights, so their average cost per

flight will be more sensitive to greater-thanexpected probability of catastrophic failure. Current] y, the NASP Joint Program Office assumes that

the probability of catastrophic failure will fall

between 0.1 percent and 0.5 percent. The average

cost per flight will also be sensitive to shorter-thanexpected wearout life. Airplanes, of course, are

designed for many more uses, but extensive reliability and maintenance data for technologically similar

airplanes is usually available.

Building and flying X-30S would demonstrate the

feasibility of single-stage, air-breathing, rocketassisted, reusable launch vehicles and would provide

data for anchoring cost estimates. It would also

provide data on which reliability estimates could be

based. Partially subjective but logically consistent

methods will be needed to predict operational

aerospace plane reliability on the basis of X-30 flight

test data (see app. A).

Making aerospace planes extremely reliable will

be important for reasons other than cost, because

they might fly many—perhaps half---of the missions

that Titans would otherwise fly, as well as the

missions that the Shuttle or an AMLS could accept.

Thus aerospace plane crews would have greater

exposure to risk than would Shuttle or AMLS crews.

The life-cycle cost of an option that includes

spaceplane development, flight testing, and—if

successful—production and operation, will depend

not on] y on the actual reliability of the plane but also

on the reliability the plane is required to demonstrate

in flight tests and on the type and level of confidence

with which it is required to demonstrate that

reliability (see app. A).

Igsee U.S. Conaess, Office of Technology Assessment, Reducing Luunch Operatums Costs New Technologies and Practices, OTA-TM-ISC-28,

(Washington, DC: U.S. Government Printing Office, September 1988), app. A, for a discussion of cost-estimating relationships.
Chapter 4

Existing Launch Systems

Photo credit: U.S. Air Force

The first commercialTitan lifts off from space launch complex 40 at Cape Canaveral Air Force Station. This commercial Titan carried

a Japanese communications satellite and a Skynet communications satellite for the British Defense Ministry.
Chapter 4

Existing Launch Systems

EXPENDABLE LAUNCHERS

Originally developed in the 1960s from intermediate-range ballistic missiles (IRBMs) and intercontinental ballistic missiles (ICBMs), the three primary

U.S. expendable launch vehicles (ELVs) have

evolved into launchers capable of launching payloads of 7,600 pounds to 39,000 pounds into low

Earth orbit (LEO)-(figure 1-1).l Though the Delta

II, Atlas II, and Titan 111 were developed with

Government funds, commercial versions of these

vehicles are now owned and operated by private

Photo credit: McDonnell Douglas Corp.

Delta expendable Iaunch vehicle, lifting off from Cape

Canaveral Air Force Station, carrying the Delta Star

(Wooden Stake”) Spacecraft for the Strategic Defense

Initiative Organization.

fins, which sell launch services to the Government

and other domestic and foreign buyers (box 4-A).

The U.S. Air Force owns and launches the Titan N.

The Air Force also operates the launch complexes

for all medium-lift ELVs, whether for Government

or commercial launches.2

Until the Shuttle was developed, these ELVs were

the only means the United States had for placing

payloads into orbit. During the early 1980s, when

the United States was pursuing a policy to shift all

payloads to the Shuttle, the Government decided to

phase ELVs out of production. Although the Government had in theory turned its ELV fleet over to

the private sector for commercial exploitation, it had

priced Shuttle launch services so low that private

launch companies were unable to make a profit

competing with the Government.3 However, following the loss of Challenger, policymakers realized

that policies that forced reliance on a single launch

system and prevented private launch companies

from entering the market were unwise.4 Hence, the

Nation now follows a policy requiring a “mixed

fleet” (both Shuttle and ELVs) to support Government needs, and a concomitant policy encouraging

private ownership and operation of ELVs. The

Commercial Space Launch Act of 1984 (Public Law

98-575), assigned the Department of Transportation

(DOT) responsibility for overseeing commercial

ELV operation.

THE SPACE SHUTTLE

Designed to carry crews as well as cargo to space,

the Space Shuttle is a piloted vehicle capable of

lifting 52,000 pounds to LE0.5 It is the Nation’s

largest cargo carrier. It was the world’s frost partially

reusable Earth-to-orbit launch vehicle. Begun in

1972, the Space Shuttle was first launched in April

1981. As of February 15, 1990, NASA has launched

the Shuttle 33 times, but experienced one tragic

failure when one of Challenger’s Solid Rocket

Boosters burned through in January 1986.

 series Delta’s payload capability from several hundred to (for 

 companies reimburse Air Force for use of the launch complexes for commercial launches.

 discussion in the and of encouraging private sector in: U.S. 

 of Technology Assessment, International Cooperation and Competition in Civilian Space Activities, OTA-ISC-239 (Springfield, National

 Information Service, July 1985), ch. 5.

 A Policy Failure?” Science, 1099-1105.

 110 nautical miles high, at 28.5” 

-41-
42 • Access to Space: The Future of U.S. Space Transportation Systems

●

●

●

●

Box 4-A—US. Medium-Lift Expendable Launch Vehicles

Delta II is the latest in a series of Delta ELVs manufactured by McDonnell Douglas. First launched in 1960,

carrying a 137 pound payload (Echo IA), the Delta has undergone a long series of improvements that have

increased its payload capacity to over 11,000 pounds to LEO, or 4,000 pounds to geosynchronous transfer orbit

(GTO). It is powered by a liquid core engine (kerosene/liquid oxygen) and strap-on solids, Originally developed

for NASA, the Delta launchers are now owned and operated by McDonnell Douglas as commercial launchers.

McDonnell Douglas carried out the first U.S. commercial satellite launch on August 27, 1989, by launching the

Marcapolo I direct broadcast satellite for British Satellite Broadcasting on a Delta 4925. It plans seven

commercial launches in 1990.

Atlas 11 ELVs are manufactured by General Dynamics for the Air Force. The Atlas II can place about 14,500

pounds in LEO and over 6,000 pounds in GTO. A commercial version of the Atlas, designated the Atlas I, is also

available. Both versions are powered by a first-stage liquid engine burning kerosene (RP-1 ), and a second-stage

liquid hydrogen/liquid oxygen Centaur engine. Solid motor strap-on boosters provide extra lift for the Atlas II.

The first commercial Atlas is expected to be launched in the summer of 1990, carrying a NASA payload—the

Combined Release and Radiation Effects Satellite.

Titan III is the commercial version of the Titan III originally built to Air Force specifications by Martin Marietta.

The Titan III design derives directly from Titan II, which was used as an intercontinental ballistic missile by the

Air Force, his propelled by a liquid core motor using hyperbolic liquids and two solid rocket motors mounted

on either side. Titan III is capable of delivering 32,500 pounds to LEO, and about 4,000 pounds to

geosynchronous orbit, In the near future, Martin Marietta plans to increase the thrust of the solid rocket boosters

to allow delivery of 40,000 pounds to LEO. The relatively high capacity of the Titan IIIq makes it possible to

launch two communications satellites to geosynchronous orbit Commercial Titan, Inc., a division of Martin

Marietta, markets the Titan III. It uses Air Force launch facilities at Cape Canaveral (on a cost-reimbursable

basis). The first commercial Titan III flight took place December 31, 1989, and sent two communications

satellites to GTO.

Titan IV is an ungraded version of the Titan III launch vehicle, manufactured for the Air Force by Martin Marietta.

Capable of carrying 39,000 pounds of payload to LEO, the Titan IV is also powered by a liquid main engine and

two solid rocket motors. The Titan IV successfully completed its maiden flight on June 14, 1989. In 1992, the

Air Force plans to add improved solid rocket motors that will boost Titan IV performance to 48,000 pounds.

SOURCE: Office of TcchnolcJgy Assessment, 1990.

The United States today depends entirely on the

Space Shuttle for transporting crews to and from

space. In space, the Shuttle functions as a vehicle for

launching spacecraft, and also serves as a platform

for experiments in science and engineering. During

the late 1990s, NASA intends to use the Space

Shuttle to deploy and service the planned Space

Station.

As the Nation looks toward the future of piloted

spaceflight, it may wish to improve the Shuttle’s

reliability, performance, and operational efficiency.

Eventually, additions to the Shuttle fleet or replacement Shuttles will likely be desirable. This section

summarizes the major issues related to maintaining

and improving the Space Shuttle.

Shortcomings of the Space Shuttle

The heavy U.S. dependence on the Space Shuttle

raises questions concerning the longevity of the

Shuttle fleet and the risk that orbiters might be

unavailable when needed.

. NASA Flight Schedule. NASA has estimated

that 14 Shuttles can be launched per year from the

Kennedy Space Center with existing facilities,6

yet it has never launched more than 9 Shuttles per

year. Some experts7 doubt that 14 launches per

year can be sustained with a 4-orbiter fleet

without adding new facilities and launch operations staff.

6~closure t. ]e[ter from D~ell R, Branscome, NASA Headquarters, to Richard DalBello, Office of Technology Assessment, Mm. 31, 1988.

TNationa] Rese~ch co~cil, Committee on NASA Scientific and Technological Program Reviews, Post-Challenger Assessment of space .Shutle

F/ight Rares and Utilization (Washington, DC: National Academy Press, October 1986), p. 15; Aerospace Safety Advisory Panel, Annual Report

(Washington, DC: NASA Headquarters, Code Q-1, March 1989), p. iv.
Chapter 4-Existing Launch Systems .43

●

Keeping the “turnaround time,” or total shifts

required to prepare an orbiter again for launch

after a flight, short is essential for reducing the

cost per flight and increasing the sustainable flight

rate. NASA will have difficulty reaching and

sustaining a rate of 14 flights per year unless it is

able to find ways of sharply reducing its current

turnaround time.8 Its present goal of 14 flights per

year assumes a processing schedule having little

margin for contingencies. Yet NASA is not

achieving the reductions of turnaround time it had

anticipated, especially for the orbiter.9 In addition,

some NASA officials have expressed concern that

the planned 90-day standdown for each orbiter

every 3 years, to make structural inspections and

modifications, may not be sufficient to accomplish all necessary work.

lnflexibility. If NASA were to prove capable of

launching 14 Shuttle flights per year, scheduling

launches at the maximum sustainable launch rate

would leave no margin to accommodate a sudden

change in launch plans or to fly extra missions on

a surge basis.

10 If more margin were reserved in

Shuttle launch schedules, an orbiter could be on

hand to be outfitted quickly for an unplanned

mission. However, even with more margin, preparing an orbiter for an unscheduled mission, such

as a Space Station rescue, could take as long as a

few months because of the lead time required for

mission planning, orbiter processing, and crew

training. 11 If the Nation wishes to improve the

safety of its crew-carrying space flight program while increasing its flexibility, NASA and

the Defense Department will have to allow

more margin in Shuttle launch schedules

(which implies fewer launches per year) and

provide alternative ELVs.

Risk of Attrition. Each time NASA launches the

Shuttle it incurs a risk of losing an orbiter from

equipment failure or human error. The Shuttle’s

success rate is 32 out of 33 flights, or 97 percent

(table 2-2).12 Estimates of Shuttle reliability

generally vary between 97 and 99 percent. For

example, the late Richard Feynman, a member of

the Presidential Commission appointed to investigate the Challenger accident, called the Shuttle

". . .relatively unsafe. . . . with a chance of failure

on the order of a percent.”13 A NASA contractor

estimated that post-Challenger Shuttle reliability

lies between 97 and 98.6 percent, with the most

likely cause of failures identified as propulsion

failures during ascent.14 One NASA division

estimated that on the Galileo mission, which was

launched October 1989, the orbiter had a 99.361

percent probability of remaining intact until

deployment of the Jupiter-bound Galileo space

probe began, 15 yet another NASA division estimated the probability would likely lie between 35

in 36 (97.2 percent) and 167 in 168 (99.4

percent). l6 If Shuttle reliability is 98 percent,

launching Shuttles at the rates now planned

would make it unlikely that Space Station

assembly could begin before another orbiter is

lost (figure 4-l).

Options for Reducing the Risks

of Depending on the Shuttle

Reduce the Shuttle flight rate. The Nation could

restrict Shuttle payloads to those requiring human

intervention, and fly other payloads on ELVs.

8Fa im~nw, NASA is d~igning tie Advanc~ Solid Rocket Motor, w~ch is now under development, to ~ capable of much quicker assembly th~

the existing redesigned solid rocket motors.

WASA Ke~y Space Center briefing, Apr. 26, 1989.

l~en a lamch a~ldent or o~er incident Cau=s a long delay in spac~r~ launches, it may &ome n~essq (X prudent to fly off Stly backlog of

payloads as quickly as possible tier recovery in a “surge” of launches.

llNom~ly, Shutde crews, paylo@, and ~ific ~biter ~ch~n up to z yws pfior to a fli@, in order to provide enough time fOr paylOid

integration and crew training.

ITm cmp~Wn, succe5s rates exwrienc~ by expendable launch vehicles range between 85 and 95 Frcent (@ble 2-2).

13’’Re~~ of tie Residential Commission on the Space Shuttle Chdenger Accidentt” app. F. (Washington, DC: U.S. Government Printing OffIce,

1986); R.P. Feymnan, What Do You Care What Other People Think? (New York, NY: W.W. Norton & Co., 1988), p. 236.

14L-SyQmS, ~c., S~~le/Shu~le-C @eratwns, Risks, and Cost Analyses, LSYS-88-008 (El Sewdo, CA: 1988).

15Gener~ E]~~c ~~o Space Division, Fi~/S@e~A~&s~ Report//for t~ Gafileo ~~swn, doc. 87 SDS4213 (Valley Forge, PA: General Ekcttic

Mm Space Division, August 1988). However, NASA supplied no rationale for its estimates of failure probabilities from which General Electric

calculated this probability, and NASA instructions had the effect of masking the overall uncertainty.

16NASAHe~qu~ers, C* QS, 1&pe&ntAssess~ntof s~~[e Acci&nt&enario probabilihesforthe Galileo Mission, VO1. 1, April 1989. The

probability of orbiter recovery after the Galileo mission would k comparable to the mission success probability, because the most likely causes of a

mission failure would probably destroy the orbiter,
●

44 ● Access to Space: The Future of U.S. Space Transportation Systems

Photo credit: National Aeronautics and Space Administration

Space Shuttle orbiter Atlantis lands at Edwards Air Force Base after completing a successful 5-day mission in which astronauts

deployed the Galileo planetary spacecraft, destined for Jupiter.

This would reduce the Shuttle flight rate and

orbiter attrition. For example, the recently

launched Galileo spacecraft, which is destined to

explore Jupiter’s atmosphere and moons,17 could

have been launched on a Titan III or Titan IV.

Except for many materials processing or life

science experiments, which require human attention, most payloads could be launched on unpiloted vehicles. The Air Force has now remanifested most of its payloads previously scheduled for the Shuttle on the Titan IV, which made

its maiden flight on June 14, 1989.18

Purchase one or more additional orbiters. If it is

judged more important to have four orbiters

available in the mid-1990s than to have high

launch rates now, Congress may wish to allow for

the potential loss of an orbiter by ordering one or

more additional orbiters as soon as possible and

limiting Shuttle launch rates.

●

●

Improve the safety and reliability of Shuttle

orbiter. Purchasing an additional orbiter of the

same design as Endeavour (OV-1O5), which is

scheduled for delivery in 1991, would not reduce

the risks to which Shuttle orbiters, crews, and

payloads are now exposed. However, the safety

and reliability of the orbiter could be improved

(table 4-l). In addition, the orbiter could be

modified to remain in orbit longer by adding

additional life support equipment, and to carry

additional payload by substituting lighter materials in current structures.

Improve the reliability of other Shuttle components. As the Challenger loss demonstrated, the

safety of the crew may depend critically on the

reliability of systems other than the orbiter and on

the practices and judgments of personnel. NASA

has already improved the design of the solid

rocket booster that failed during Challenger’s last

 was for the it to launch on an ELV

would have been prohibitively expensive.

 With processing, and Titan necessary it considered an 

vehicle.
Chapter &-Existing Launch Systems ● 45

Figure 4-1-Probability of Retaining 3 or 4 Shuttle Orbiters Over Time

Probability of having at least three or four orbiters

1

0.5

0

after flight 30 40 50 60 70 80 90 100110120130140150160 170180190200

I I

Endeavor begin

(Ov=105) Space station

on line

Shuttle reliability is uncertain, but has been estimated to range between 97 and 99 percent.1 If the Shuttle reliability is 98 percent, there

would be a 50-50 chance of losing an orbiter within 34 flights. At a rate of 11 flights per year, there would be a 50 percent probability of losing

an orbiter in a period of just over 3 years. The probability of maintaining at least three orbiters in the Shuttle fleet declines to less than 50

percent after flight 113.

Although loss of an orbiter would not necessarily result in loss of life, it would severely impede the progress of the civilian space program,

as it would likely lead to a long standdown of the orbiter fleet while the cause of the failure as determined and repaired.

 Operations, and Cost Segundo, 

SOURCE: Office of Technology Assessment, 1990

ascent and successfully employed the redesigned

solid rocket motors (RSRMs) in 8 flights since

September 1988. NASA is currently working on

an Advanced Solid Rocket Motor (ASRM) that

will replace the RSRM. It has also studied the

feasibility of replacing the Shuttle’s solid rocket

motors with Liquid Rocket Boosters (LRBs).

NASA’s studies indicate that developing Shuttle

LRBs might cost about twice as much ($3 billion)

as developing ASRMs. Nevertheless, LRBs may

be safer than ASRMs because liquid engines can

be ignited and checked before lift-off, then shut

off if faults appear. 19 If one, or even two, liquid

engines were to fail after lift-off, they could be

shut down, allowing the Shuttle to land at an

alternative landing site. They can even be throttled during launch without incurring loss of life.

Although a solid rocket motor could be designed

to have its thrust terminated during flight, doing

so on the Shuttle would lead to destructive thrust

Table 4-1-Selected Possible Improvements

for New Orbiters

Safety end reliability

● Improved propulsion

. Simplified hydraulics

. Increased strength skins

. Improved attitude control

. Suppressed helium overpressure

Cost reductions

● Simplified cooling

● Modernized crew displays

. Improved tile durability

● Modernized telemetry

Performance

● Extended duration orbiter

. Weight reduction

. Local structure strengthening

. Global Positioning Satellite receiver-computer for navigation

SOURCE: Rockwell International Corp. and Office of Technology Assessment, 1990.

 Lift for the 1989, pp. 22-25.
46 ● Access to Space: The Future of U.S. Space Transportation Systems

imbalance. 20 NASA is currently conducting studies to understand the potential benefits and

drawbacks from substituting LRBs for solid

rocket motors.

A Shuttle Improvement Program

Making major Shuttle enhancements on an individual project-by-project basis may not be the most

efficient way to improve the Shuttle system. To

choose one improvement may mean not pursuing

another, worthwhile avenue. However, having a

versatile, capable launch fleet that provides reliable

human access to space will be essential if Congress

wishes to maintain a policy of supporting the human

presence in space. Hence, Congress may want to

consider an integrated approach to strengthening the Nation’s space transportation capability

by funding a Shuttle Improvement Program

(table 4-2) lasting, for example, 10 years. Such a

program could include development of advanced

solid rocket boosters, liquid rocket boosters, and the

Shuttle-C, as well as additional, more modest,

improvements summarized in box 4-B. To support

this sort of program, which could cost as much as

$850 million per year for 10 years above the current

projected cost of the Shuttle program, would require

finding extra space program funding, scaling down

the Space Station program, or deferring other

programs. In addition to leveling out budgetary

requests for the 10-year period of the program, an

integrated improvement program could lead to the

development of technologies and systems that

would be needed for new crew-carrying systems

should Congress decide to pursue a more ambitious

space program in the future.

SMALL LAUNCH SYSTEMS

Most of the Government’s attention has focused

on medium- or heavy-lift launch vehicles.21 However, recent interest in lightweight spacecraft, designed for a range of specialized activities, such as

store-forward communications, single-purpose remote sensing, and materials processing research, has

generated a concomitant interest in small vehicles to

Photo credit: Orbital Sciences Corp. and Hercules Corp.

An artist’s conception of the Pegasus air-launched vehicle

ascending to orbit after being launched from an aircraft.

launch them. Launchers of this class are particularly

appropriate for private sector development, as the

costs and risks are modest compared to higher

capacity launch systems. If small payloads prove

effective for a wide variety of military and civilian

uses, the demand for small launchers could grow

substantially .22

● Scout. Originally developed in the late 1950s

and early 1960s, the Scout launcher is capable

of carrying about 600 pounds to LEO. Scout is

a four-stage vehicle, propelled by solid rocket

motors, which is manufactured by the LTV

corporation under contract to NASA. As soon

as the remaining vehicles have been flown,

NASA will retire it from service, unless LTV,

%ee U.S. Congress, Office of Technology Assessment, Round Trip to OrbitHumanSpuceflightAlternatives, OTA-ISC419(Washington, DC: U.S.

Government Printing Office, August 1989), pp. 45-48 and app. A, for a detailed comparison of solid and liquid engines.

zlHowever, tie relatively small Atlas-E ( 1,750 pounds to low-Earth Polar orbit) and Titan 11 (4,200 pounds to low-Earth polar orbit) launchers, which

originally served as intercontinental batlistic missiles, have been used to launch a variety of Government payloads. Neither of these vehicles are available

for commercial use or for launching non-Government payloads.

zzLamnce H. Stem ~t. al., An Assessment of po[entia/ ~urkers for S~J/ Sa/e//ifes (Herndon, VA: Center for hovative TwhxIoIogy, November

1989); “Lightweight Launches to Low Orbit: Will a Market Develop?” Space Markers, Summer 1987, pp. 54-58.
Chapter 4-Existing Launch Systems ● 47

Table 4-2-A Possible Shuttle Improvement Program

Options cost Benefit

Orbiter improvements:

Develop alternate turbopumps for Space Shuttle main engines . . . . . . .

Automate orbiter for unpiloted flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Extend orbiter flight duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Built-in test equipmentc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Booster improvements:

Increase thrust of redesigned solid rocket motor (RSRM). . . . . . . . . . . .

Continue to develop advanced solid rocket motor (ASRM). . . . . . . . . . . . .

Develop liquid rocket booster (LRB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Other elements:

Develop lightweight external tank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Complementary Vehicles:

Develop Shuttle-C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$228 milliona

$200 millionb

$120 million

[?]c

$50 to $60 million

$1.3 to $1.8 billion

$3.5 billion

[?]

$1.5 billion

Safety andeoonomy

Safety

Utility

Safety and economy

More payload

Safety and more payload

Safety and more payload

More payload

For cargo

Develop capsule or lifting body for Space Station escape . . . . . . . . . . . . . . $0.7 to $2 billion Safety

aAiready funded by NASA.

klnfy $30M to $40M for each additional ohiter.

c-e oTA.TM.IsC.28, Redua.ng Launch Operations costs.

NOTE: Most of these options would increase Shuttle payload capability, but by different amounts; their other benefits and their dates of availability would differ.

Therefore, two or more options might be pursued, for example, ASRMS to increase Shuttle paylod capability and LRBs for increased safety and

redueed environmental impact. -

SOURCE: Office of Technology Assessment, 1990.

or some other private firm, decides to offer it

commercially .23 On a cost per pound basis,

Scout offers a relatively expensive way to reach

space ($12,000 per pound).

Pegasus. The Lightsat program, initiated by the

Defense Advanced Research Projects Agency

(DARPA), has created a market for at least one

new small launcher, the Pegasus, capable of

launching between 600 and 900 pounds to

LE0.24 Pegasus is a three-stage, solid-fuel,

inertially guided winged rocket that is launched

from a large aircraft. It is the first all-new U.S.

launch vehicle design since the 1970s, though

it depends heavily on propulsion and systems

originally developed for intercontinental ballistic missiles; it uses engines designed for the

Midgetman ICBM.

Pegasus has been developed as a joint

venture between Orbital Sciences Corp. (OSC)

and Hercules Aerospace Co., and funded entirely with private capital. DARPA negotiated

a price of $6 million per launch for a possible

six launches. The Air Force has assumed

responsibility for the oversight of the launch of

Pegasus for Government payloads. To date,

two launches have been ordered; the first one,

●

which will carry two payloads, is scheduled for

spring 1990.

A mobile launch system such as Pegasus

could provide a survivable means for

launching small military satellites in wartime to augment satellites launched in peacetime or replace any satellite damaged by

anti-satellite weapons. However, the Department of Defense has not stated a need for a

survivable launch capability. The first flights of

Pegasus will employ a B-52 as the carrier. OSC

plans to acquire a large commercial aircraft,

such as a Lockeed L1011, to serve as a launch

platform for commercial flights.25

Industrial Launch Vehicle, The American

Rocket Company (AMROC) is developing a

family of suborbital and orbital rockets, called

the Industrial Launch Vehicle, powered by a

hybrid, solid-fuel/liquid-oxygen engine.

AMROC’s hybrid design uses liquid oxygen to

burn nonexplosive solid propellant similar to

tire rubber. Such hybrids would have some

safety advantages and might be allowed in

areas where conventional solid- or liquid-fuel

rockets are not. They could, for example, be

used to launch small satellites from mobile

23LTV and tie Italian corporation SNIA BPD are discussing developing an upgraded Scout H, capable of launching about 1,200 pounds to LEO ~

a cost of about $15 million per mission.

24Joseph AlPer, “Riding an Entrepreneurial Rocket to Financial Success,” The Scientist, July 25, 1988, pp. 7-8.

zson a pr-po~d b~is, Pegasus currently costs $6,000 to $10,000 perpound of payload, which is much higher than competing, ISrger 1aunch sYstems.

However, for some customers, the ability to launch from many different locatiom and relatively quickly (once the concept has been proven and

operational procedures are streamlined) will outweigh the relatively high per pound cost of the Pegasus.
4/I . Access to Space: The Future of U.S. Space Transportation Systems

Buying Additional Orbiters

Three basic options are available:

Build a copy of OV-]05

The Challenger replacement (OV-1O5), already

being built includes several important improvements:

-addition of an escape hatch and pole;

—improved heat shielding tiles, strengthened

landing gear, wing structure, and engine pod;

—more than 200 internal changes, including

electrical rewiring and improvements in the

braking and steering systems.

Implement additional improvements

—safety/reliability;

-cost reduction; and

—performance.

(Some of these upgrades may involve structural

changes, and therefore could not be made in

existing vehicles.)

Reduce airframe weight-Orbiter airframe

weight reduction of 8,000 to 10,000 pounds could

be achieved through the use of:

-composite materials;

—alloys;

—intermetallic alloys; and

—high-temperature metallics.

Incremental Changes

Some alterations to the Space Shuttle system have

already been accomplished, or are already underway:

Redesigned Solid Rocket Motors (RSRMs)

Space Shuttle Main Engine Improvements—

Specific efforts directed at longer life and higher

reliability include improved:

—welds;

—manufacturing techniques;

-nondestructive testing;

—heat exchangers;

--controllers;

-engine health monitoring; and

—-turbopumps.

On-Board Computer Upgrades-Specific efforts

include:

—identical computer modules ‘mass-produced”

for economy,

--connection by optical fibers, and

—a high degree of fault-tolerance.

Other improvements NASA has considered or is

now working on:

● Extended Duration Orbiter (EDO)-NASA is

building in the capacity to extend on-orbit stays

from the current 7 days to 16-28 days.

Automatic Orbiter Kit—An existing Shuttle orbiter could be given the capability to fly an entire

mission automatically without a crew.

Operation Improvements-Introducing a numb&r of new technologies and management strategies to make Shuttle launch operations more

efficient and cheaper, e.g., improved Shuttle tile

inspection and repair, and expert systems for

control.

Major Changes

Some candidates include:

●

●

Advanced Solid Rocket Motors (ASRMs)--These

would replace the existing RSRMs. Compared to

the RSRMs, they offer:

—up to 12,000 pounds additional lift capacity,

--better manufacturing reproducibility,

—reduced stress on the Space Shuttle Main

Engines,

—potentially higher reliability, and

—potential for enhancing competition.

Improve Redesigned Solid Rocket Motors—l%

existing RSRMs could be improved further by

redesigning them to increase their thrust. The

Shuttle’s payload capacity could be increased by

6,000 to 8,000 pounds by substituting a more

energetic solid propellant and by making other

requisite changes to the motors.

Liquid Rocket Boosters (LRBs)--They would

replace the solid boosters on the Shuttle. Compared to RSRMs, LRBs offer:

—safer abort modes;

-up to 20,000 pounds additional lift capacity;

—long history, potentially greater mission reliability;

-capability of changing mission profiles more

easily;

—safer Shuttle processing flow;

—-potential application as an independent launch

system; and

—better environmental compatibility.

Materials improvements-’l’he emphasis on improved materials has focused particularly on

saving weight. For example, using aluminumlithium (A1-Li) for the external tank instead of the

present aluminum alloy could provide a 20 to 30

percent weight savings. Using composite

materials in the orbiter wings and other parts

could save an additional 10,000 pounds.

Crew Escape Module—-This would allow for safe

escape over a larger portion of the liftoff regime

than now possible. It would replace the escape

pole system presently in place, but would be

heavier and much more costly.
Chapter 4-Existing Launch Systems • 49

●

●

launchers. AMROC’s first attempted launch of

its hybrid system on October 5, 1989 was

aborted when a liquid oxygen valve failed to

provide enough oxygen to support adequate

thrust.26 Significantly, the rocket neither exploded nor released toxic fumes, demonstrating

one of the safety features of using hybrid

systems. Instead, it burned on the pad, doing

relatively little damage to the pad (between

$1,000 and $2,000) or to the two payloads it

was to carry on a suborbital flight. AMROC has

several customers interested in its launch vehicle, but to date has no firm launch contracts.27

Standard Small Launch Vehicle (SSLV). The

SSLV is being developed by the Defense

Advanced Research Projects Agency (DARPA).

DARPA recently awarded a contract for purchase of SSLV launch services to Space Data

Corp., a division of Orbital Sciences Corp. The

first stage of Space Data’s Taurus SSLV will be

the first stage of an MX missile booster; the

three upper stages of this vehicle will be the

same solid rocket engines that power the

Pegasus. Taurus is designed to carry a 1,500

pound satellite to a 400 nautical mile polar

orbit, or a 3,000 pound spacecraft to LEO. It

could even be used to launch an 830 pound

satellite to geosynchronous transfer orbit.28

Taurus will be fully transportable and capable

of being launched quickly on a few months

notice from a variety of launch sites. The first

DARPA demonstration launch is scheduled for

July 1991. DARPA holds options for four

future flights on Taurus.

Conestoga. Space Services Inc. (SSI) is developing a family of launch vehicles called

Conestoga, which will use Castor solid rocket

motors strapped together indifferent configurations to achieve payload lift capacities of 900 to

2,000 pounds to polar orbit and 1,300 to 5,000

pounds to LEO. Launch services to LEO will

cost $10 million to $20 million, depending on

payload size and vehicle configuration. To

date, SS1 has no firm orders for launch services

●

on Conestoga, although it has several prospects. SSI successfully launched its Starfire I,

the first U.S. commercial sounding rocket on

March 29, 1989. However, on November 15,

1989, the second sounding rocket flight failed.

EPAC “S” Series. E’Prime Aerospace Corp.

(EPAC) is developing a series of ELVs propelled by rocket motors developed for the MX.

EPAC is offering seven different launch vehicle configurations capable of placing payloads

of up to 36,000 pounds in LEO. Prices charged

commercial customers will range from $18

million (for 5,781 pounds to LEO) to $84

million (for 36,138 pounds to LEO). Government prices would be lower.29 It plans to make

its first orbital launch of the S-1 in 1991.

Other companies, both large established firms and

smaller, startup companies, have offered small

launch vehicle designs in the launch services market.

Lockheed Missiles and Space Co. has designed a

launch vehicle that would use Poseidon Fleet

ballistic missile components to carry 850 pounds to

polar orbit or 1,200 pounds to LEO. Pacific American Launch Services, Inc., is working on the design

of a single-stage, liquid oxygen-hydrogen launcher

that would carry 2,200 pounds to LEO.

In addition to these U.S. examples, several foreign

firms are offering to sell launch services on small

launchers. For example, a consortium in northern

Europe is developing a small, solid rocket-powered

launcher named LittleLeo. The Soviet Union has

suggested converting some of its SS-20 mobile

missiles for use as small commercial launchers.30

The market created by DARPA made possible the

development of Pegasus and Taurus. At this time, it

is unclear whether private sector demand for small

spacecraft will be sufficient to support a truly

commerical launch market for small launchers.

However, several aerospace companies, including

Orbital Sciences Corp., Hughes Aircraft Corp., and

Ball Aerospace Co. are working on designs for small

satellites for communications and remote sensing,

which will test market potential over the next few

-e liquid oxygen valve failed to open sufficiently, probably as a result of heavy icing m the relatively humid climate of Vandenberg Air Force Base

where the test launch was attempted. Michael A. Dornheim, “Arnroc Retains Key Personnel Despite Cutbacks After Pad Fire, ’’Aviation Week and Space

Technology, Oct. 30, 1989, p. 20.

27Jmes BeMett, AMROC, ~em~r 1989”

XW~guW, ~ Boosters Combind for New ~fen~ Launch Vehicle,” Aviurion Week and Space Technology, Sept. 18, 1989* PP. 47~8”

2gBob Davis, EPAC, Mar. 12, 19W.

s~~et~ in tie United States by Space Commerce COrPOmtion.
50 ● Access to Space: The Future of U.S. Space Transportation Systems

years. The construction of non-Federal launch sites

would assist the process of developing a market for

small spacecraft and launchers.31 Groups in the

States of Florida, Hawaii, and Virginia have shown

considerable interest in constructing launch sites for

the private market.

Military demand for small launchers may be

substantial, as some elements in the services are

interested in developing small spacecraft for tactical

surveillance and communciations. SDIO may have

a near-term requirement for launching small spacecraft to support ballistic missile defense. Although

the cost per pound of payload carried on small

launchers is currently high, a large market for small

launchers may help to bring costs down over time.

However, private companies will have to amortize

their development costs, which will tend to keep

launch costs per pound of payload relatively high

compared to larger systems for which the development costs were borne by the government years ago.

qlHowever, ad~tion~ launch sites might r~uce the market for Pegasus by increasing availability of alternate launch SiteS.
Chapter 5

Space Transportation and

the Space Station

of Space Station Freedom, which is scheduled

Photo credit’ National Aeronautics and Space Administration

for completion by the end of the century.
Chapter 5--Space Transportation and the Space Station ● 55

Box 5-A-Escape Vehicles

Several contingencies could require emergency escape of personnel in space. These include medical

emergencies of Space Station crewmembers, major equipment failures, damage from orbital debris, etc. Escape

could also be necessary if the Shuttle failed to meet its scheduled launch date by so long a time that the Station risked

running out of critical supplies.

Crew Emergency Return Vehicles (CERV)

NASA is considering two types of vehicles for emergency return from space to Earth:

• Capsule—This simple vehicle would have an ablative heat shield reminiscent of reentry capsules from the

early days of spaceflight, and still used routinely by the Soviet Union. A capsule, which could closely

resemble the Apollo capsule, would descend by parachute and land in the ocean. Its advantages include

simplicity, relatively low cost, and proven technology, In addition, capsules need little or no piloting, which

could be a major consideration if pilots are unavailable or unable to function as a result of injury or a long

stay in orbit. Depending on its capability, a capsule could cost $0.75 billion to $1.0 billion to develop.

• Small Glider-A small, aerodynamically stable vehicle whose shape would provide lift and could land by

parachute or at low speed on a runway. A glider could reach a wider range of landing sites and have more

opportunities for reentry and recovery (particularly for a version with landing gear), and a softer ride than

capsules (important if an injured crew member is returning). However, a glider would cost 20 to 50 percent

more than the simplest parachute version of a capsule.

ingly, even eagerly, accept such duty despite the The NASP program is also evaluating the poteninherent risks of spaceflight. Although they should

not expect to be exposed to unnecessary risks, their

duty will never be risk free.

A rescue system, if built, would be needed for the

life of the Space Station. Therefore, its total operating costs can be expected to exceed its development

costs. Before committing to a specific rescue

strategy, system designers will have to address

the costs of developing the necessary support

infrastructure, which might include ground operations hardware and personnel at the mission

control site, landing site crews, and the necessary

subsystems and logistics support to resupply,

replenish, and repair a rescue vehicle on orbit.

tial for using an operational aerospace plane for

Space Station crew rotation and rescue. Using an

aerospace plane for rescue would provide two

primary advantages: 1) there would be no need to

build and support a dedicated vehicle and its

associated infrastructure and personnel; and 2) it

could be based on Earth, rather than in space, making

it easier and cheaper to maintain. However, NASA

expects to complete Phase I of the Space Station

before 2000, and an operational aerospace plane

could not be ready before it does so. Hence, an

aerospace plane could not serve to replace or rescue

crew from the Space Station until 2005 or later, if at

all.
Chapter 5

Space Transportation and the Space Station

The planned international Space Station will

make long-term demands on space transportation for

construction, servicing, supply, and possibly emergency crew return. Current NASA plans call for

making at least 29 Shuttle flights (including several

logistics flights) between 1995 and 1999 to build the

station, and about 5.5 flights per year thereafter to

operate it. Some flights will be required to rotate

station crew, some for delivering or returning cargo.

SPACE SHUTTLE

Uncertainty about the adequacy of the current

Shuttle fleet for constructing and servicing the Space

Station makes station planning uncertain and risky.

Deployment, servicing, and resupply of the Space

Station face the dual risks of delayed launch

schedules and loss of one or more orbiters. In

addition, losing a critical element of the Space

Station in transit to orbit as a result of a Shuttle

failure could lead to long delays in Space Station

constructional

Chapter 4 outlined options for reducing the risk of

using the Shuttle for Space Station construction and

operation. However, most of these options would

require additional funding beyond NASA’s projected budget for Space Station or for space transportation. Congress may wish to postpone Space

Station construction and operation and focus on

improving the Nation% ability to place crews in

orbit safely and reliably. Alternatively, Congress

could direct NASA to fly fewer non-Space Station-related Shuttle missions in order to reduce

the risk that a Shuttle would be lost before Space

Station construction is completed.

NASA might, for example, plan to use Titan IVs

to carry some Space Station elements into orbit

rather than risking the Shuttle to do so. However, the

availability of Titan IV is highly uncertain, as the Air

Force appears to need all the Titan IVs it has

purchased for the period of station construction.

NASA might also develop the Shuttle-C for Space

Station construction. Furthermore, as noted earlier,

science payloads now tentatively manifested for the

Shuttle, if properly designed, could be flown on

ELVs purchased competitively from the private

sector.

RESCUE OR ESCAPE VEHICLES

Crews living and working in the planned Space

Station could be exposed to substantial risk from

major failures of the Station or the Space Shuttle that

transports the crew. For example, orbital debris from

previous space activities could puncture one of the

crew modules, causing a need to evacuate the crew

and return them to Earth.* NASA is attempting to

reduce such risk by building safety features into the

Space Station and improving the Shuttle’s design.

Nevertheless, many analysts in NASA and the

broader U.S. space community believe that the

United States should develop some means independent of the Shuttle to rescue crews from the Space

Station.

NASA is studying the possibility of building a

specialized vehicle that could be launched into space

atop an expendable launch vehicle as well as return

from the Space Station (box 5-A). Such a vehicle,

which NASA calls the Assured Crew Return Vehicle

(ACRV), 3 could be used to provide:

1. crew emergency rescue,

2. access to space by crews,

3. small logistics transport, and

4. on-orbit maneuver.

Emergency rescue vehicles could be developed

and launched on a Titan III or Titan IV by 1995 or

1996. Alternatively, a Shuttle could carry two at a

time, to be docked at the Space Station.

To decide whether a risk-reducing effort is

worth the investment required, Congress must be

advised about how much the investment would

reduce the risk. Even if an alternate crew return

capability were provided and worked as planned,

it would not eliminate all risks to station crewmembers. To gain perspective on the decision,

Congress may wish to weigh the risks with and

IIf a Space Smtion element for which there was no spare were lost, replacing that element would take many months.

2~ 1983, a pant ~fip from a ~ace object ~vere]y damag~ a Windshield on he shuttle orbiter C~&nger. Nicholm L. Johnson and Darren S.

McKnight, Art~icial Space Debris (Malabar, Florida: Orbit Book Company, 1987), pp. 4-5.

3Note, however, mat ~~ou@ he A~v may Fovide a high probability of re~rn from space, it d~s not necessfily provide Usllltd Silfe retlKIl,

as there will still be a non-negligible degree of risk connected with the vehicle and the procedures rquired to operate it properly.

–53 –
54 ● Access to Space: The Future of U.S. Space Transportation Systems

Photo credit: National Aeronautics and Space Administration

Artist’s conception of an Apollo-type emergency rescue vehicle entering the Earth’s atmosphere after leaving the Space Station.

without a rescue vehicle against the risks of other crew-carrying space transportation systems than to

hazardous duty in the national interest.4

build a crew escape craft. The use of a rescue

A risk assessment of the Space Station should take system would itself expose Space Station crewinto account all phases of the crews’ experience in members to a certain element of risk, which must

space. For example, if the greatest risk to Space also be assessed before making any decision

Station crewmembers were experienced during about whether or not to build such a system.

flight to orbit, it may prove more cost-effective to Finally, it would be well to remember that the Space

improve the safety of the Shuttle or any later Station crew will be volunteers, who would will-

 on off-shore oil platforms, or piloting 
Chapter 6

Reducing Space System Costs 

Photo credit: General Dynamics Corp.

Artist’s conception of an Advanced Launch System launch vehicle
Chapter 6

Reducing Space System Costs

Reducing the cost of exploring and using the

space environment is crucial to the continued

development and exploitation of outer space. America’s wish list for projects in outer space far exceeds

its ability to pay, given the many pressures on the

Federal budget. Launch costs currently range from

$3,000 to $12,000 per pound to reach low Earth orbit

(LEO), depending on payload weight and the launch

system employed. Launching communications satellites into geosynchronous transfer orbit costs

between $11,000 and $20,000 per pound. If these

costs could be reduced significantly, outer space

would be more attractive to potential users, both

within Government and in the private sector. However, for many spacecraft, space transportation costs

are relatively small compared to the costs of

designing and building the spacecraft. Hence, reducing spacecraft costs plays an essential part in

bringing down overall space program costs.

SPACE TRANSPORTATION

New technologies promise to make the process of

manufacture, assembly, and processing of launch

vehicles less expensive (table 6-l). The Advanced

Launch System (ALS) program, for example, is

exploring a wide variety of technologies that could

be employed to reduce space transportation costs.1

However, for these technologies to be effective,

new management practices must be introduced

(table 6-2). Launch operations, for example, tend

to be highly labor-intensive, and comprise a

significant percentage of the cost of a launch. As

the example of the Delta 180 experiment for the

Strategic Defense Initiative Office demonstrated,

sharply reducing the burden of oversight and review

in a project, and delegating authority to those closest

to the technical problems, can result in meeting a

tight launch schedule and reducing overall costs.2 In

addition, launch system designs that reduce the

number and complexity of tasks requiring human

involvement would also contribute to reducing costs

(table 6-3). The ALS program is also assessing

various management and organizational techniques

that would speed launch processing and reduce its

complexity. It has incorporated some of the features

of the so-called Big Dumb Booster concept (box

Table 6-1--Cost-Saving Technologies for

Launch Systems

. Automated manufacturing processes

● Advanced, lightweight materials

● Automated data management system

. Automated test and inspection

. Automated launch vehicle and payload handling

. Modular subsystems

● Database management systems

. Computer-aided software development

. Expert systems

SOURCE: Office of Technology Assessment, 1990.

Table 6-2-Cost-Reducing Strategies

. Reduce documentation and oversight

. Create better incentives for lowering costs

. Provide adequate spares to reduce cannibalization of parts

. Develop and use computerized management information

systems

. Use an improved integrate/transfer/launch philosophva

aThe integrate/transfer/launch (ITL) philosophy refers to the prWtiCe Of

separating categories of launch operations procedures to make each more

efficient.

SOURCE: Office of Twhnology Assessment, 1990.

Table 6-3-Launch System Design Strategies

. Engage all major segments of launch team in launch system

design process

. Design for simplicity of operation as well as performance

. Design for accessibility and modularity

SOURCE: Office of Technology Assessment, 1990.

6-A) in its planning, viz., the concept of designing a

launch system to achieve minimum cost, rather than

maximum performance.

Purchasing launch services competitively from

private firms, rather than managing launches from

within NASA or the armed services might well save

money. The intent of purchasing launch services is

to remove the Government as much as possible from

setting detailed engineering specifications for the

launch system and to reduce the burden of excessive

oversight by Government managers. Several entrepreneurial launch vehicle firms are developing

new launch systems for small or medium-size

payloads (see Small Launch Systems in ch. 4). These

projects present opportunities to incorporate lowIu,s, conye~~, Offjce of TechnoloW Assessment, Reducing Launch Operations Costs New Technologies ad practices, OTA-TM-ISC-28

(Washington, DC: U.S. Government Printing Office, September 1988) for a detailed discussion of these points.

Zwpmment of ~fenw Swategc Wfense ~itiative Office/Kinetic Energy Office> “Delta 180 Final Report,” vol. 5, March 1987.

-59-
60 ● Access to Space: The Future of U.S. Space Transportation Systems

Box 6-A--The Big Dumb Booster Conceptl

Some launch system analysts believe that a “Big Dumb Booster”2 using modern technology could markedly

reduce space transportation costs. Other analysts disagree. Current U.S. expendable launch vehicles (ELVs) are

derived from 1960s intercontinental ballistic missile designs that used high-performance engines and lightweight

structures in order to minimize launch vehicle weight and maximize payload and range. Launch system designers

gave relatively little priority to reducing launch costs.

The genesis of the Big Dumb Booster debate derives from analysis done in the 1960s that indicated that launch

vehicles could be designed to minimize manufacturing and operational costs by making them larger or heavier.

Launch vehicles designed to achieve sharply reduced costs would be very different from today’s launch vehicles.

For example, according to this concept, the first stages of a rocket should be relatively unsophisticated, and heavier

hardware produced at lower unit costs by relaxing manufacturing tolerances should replace expensive,

state-of-the-art, lightweight hardware.

Although in the late 1960s several aerospace companies performed systems studies on minimum-cost launch

vehicles, and the Government tested some demonstration pressure-fed engines, no systematic, thorough analysis

of the overall life-cycle costs3 of such a booster has been done. The Big Dumb Booster concept remains

controversial. Supporters of the concept argue that it still has considerable merit and that it is not too late for the

United States to adopt this rocket design philosophy. Opponents maintain that time and improved technology have

passed it by.

Specific designs that might have been the minimum-cost solution two decades ago are certainly not

today% minimum-coat design. Technology has advanced since the early Big Dumb Booster studies,

significantly altering potential trade-offs among cost performance, and weight. Objective evaluation of the Big

Dumb Booster concept would require systematic analysis, with attention to engineering details and costs. It would

also involve some hardware development and testing. If a Big Dumb Booster study is done, it should be carried out

as a systems study that integrates specific hardware choices with the entire system, including the launch facilities,

logistics, launch and support. It should also include estimates of the demand expected for such a booster, as future

demand would have a marked effect on program life-cycle costs. Such a study might also include consideration of

recovery and reuse.4 A Big Dumb Booster concept study might cost between $5 million and $10 million, depending

on its scope. If Congress decides that the Big Dumb Booster requires more focused evaluation, it could task NASA

or the Air Force to carry out such studies.

Iu,s. eon~ss, OffW of TWhnology Assessment, Big IXunb Boosters: A bw-Cost Space Transporxuiun Qption? lkzckgro~~qer

(Washington, DC: International Seeurity and Comrneree Program, 1989).

2~e Em Big D-Booster ~~n appl~~ to a wide variety of concepts for low-cost launch vehicles, eWWi~lY ~~ ~~ would

use ‘WV t.eehRoIQgy” approaches to engines and propellant tanks in the booster stage. As used in this report, it refers to launch systems desimed

for minimum cost by using simplified subsystems where appropriate.

3Life+y~I~ ems include not only the costs of tnanufaeturing the launch vehicle, but also the costs of ground WXWkXM Wd launch

facilities, developing and testing. It also includes the discounting of all these costs to refleet opportunity costs and inflation.

4For ~xmp~e, tie Nav~ R~~h MWEMOty is now exploring a reusable sea-launched bOOSttW that would use a WW* liquid

propellant,

SOURCE: Office of Technology Assessment, 1990.

cost approaches at little direct3 cost to the Govern- suggest that the government role, which may be vital

ment. ‘However, launch firms complain that the cost during the development and demonstration phases

of continued excessive government oversight and of a new, complicated technology, becomes countercomplicated procurement regulations unnecessar- productive when the basic technology has been

ily raises the costs of launch services. They argue successfully acquired and is needed for ongoing

that the cost of government oversight far exceeds the operations. Then, matters of cost and reliability

actual cost risk of a failed mission. Launch firms become paramount. However, Government users

3fivate development will ~eSult in some indirect costs t. the Gover~ent. However, If ~ese firms we operating within a competitive market, the

eventual cost to the Government should be lower than if the Government paid for the improvements directly.

dFor a de~]~ discussion of the DoD acquisition system, especially rules and oversight, see U.S. Congress, ~fice of TtXhnOIOSY Assessment,

Holding the Edge: Maintaining the Defeme Technology Base, OTA-ISC420 (Washington, DC: U.S. Government Printing Office, April 1989),

especially ch. 8.
Chapter Reducing Space System Costs ● 6 1

may fear that boosters not built to government

specifications might be too unreliable, especially for

one-of-a-kind spacecraft.

Current space policy provides for the civilian

agencies to “encourage, to the maximum extent

feasible, a domestic commercial launch industry by

contracting for necessary ELV launch services

directly from the private sector or with DoD."5

Extending this policy to all Government

launches, both civilian and military, except those

on the Space Shuttle, could also save the Government money, but only if Government oversight

and paperwork were reduced.

The Federal Government might encourage the

private sector launch industry by issuing space

transportation vouchers to space scientists whose

experiments are being supported by the government. 6 These vouchers could be redeemed for

transportation on any appropriate U.S. launch vehicle, and would free scientists to choose the vehicle

they thought most suitable to the needs of the

spacecraft. This policy would free space scientists

from dependence on the Shuttle and its schedule. It

might also increase opportunities for researchers to

reach space. By reducing scientist’s dependence on

the Shuttle, such a policy should help in raising the

demand for ELVs and in bringing down the cost of

space transportation.

PAYLOADS

Dramatic reductions in launch costs will not,

by themselves, lower spacecraft program costs

substantially, because it may cost from $40,000 to

$650,000 per pound to design and build many

payloads, 7 while it costs only about $3,000 per

pound to launch one to LEO. Reducing launch

costs to $300 per pound, a goal of the ALS program,8

may reduce the total cost of procuring and launching

an expensive spacecraft by less than 2 percent.

Commercial communications satellites, however,

often cost on the order of $10,000 per pound.

Because they need to be placed in geosynchronous

orbit, which is more expensive to achieve than LEO,

the cost of a launch is comparable to the cost of the

payload. Therefore, commercial operators are extremely interested in cost reductions in both areas.

To reduce payload costs, and for other reasons,

novel approaches to payload design and fabrication

have been proposed:

●

●

Provide for Weight Margin: Designing payloads to fit launch vehicles while reserving

ample size and weight margins can reduce the

risk of incurring delay and expense after

assembly has begun.

Satellites often grow substantially heavier

than expected as they proceed from design to

construction. If a payload grows so heavy that

its weight equals or exceeds the maximum

allowable gross lift-off weight, the payload

must be redesigned, which causes delay and

increases cost. To reduce the risk of exceeding

vehicle payload capacity, program managers

could require designers to allow extra weight

margin for such contingencies. However, this

design philosophy would lead to more stringent

size and weight constraints than would otherwise be imposed. In many cases, sufficient

margin could be provided by clever design,

e.g., by designing several smaller singlemission payloads, to be launched separately,

instead of a single multimission payload.9

Fatsats: If payloads were allowed to be heavier

for the same capability, some could cost

substantially less. For example, OTA estimates

that Titan-class payloads that cost several

hundred million dollars might cost about $130

million less if allowed to be five times as heavy.

If payloads were allowed to be much heavier, a

manufacturer could forego expensive processes

for removing inessential structural material, as

well as expensive analyses and tests. Standardized subsystems, which could be produced

economically in quantity, could be used instead

of customized subsystems. Designers could

also add redundant subsystems to increase

smite House, Office of the press Secretary, “National Space Policy,” NOV. 2, 1989, P. 11.

6MO]]Y Ma~a~eY, “Launch Vouchers for Space Science Research,” Space P~/icy, vol. 5, No. 4* PP. 311-320.

TThe low end of~s range is for payloads consisting mosdy of fuel; the high end would be for some satellites c~ing liE1e or no fuel. U.S. Congress,

Office of Technology Assessment, Affordable Spacecraft: Design and Launch A/ternafive~4ackgrouti Paper, OTA-BP-ISC-60 (Washington, DC:

U.S. Government Printing Office, January 1990).

8101 stat. 1067.

9’l%e number of new program starts allowed in a year tends to force program managers to add additional capabilities to the spacecraft. In addition,

in some cases, a larger spacecraft bus can accommodate more functions at a reduced cost per function compared to multiple smaller buses.
62 ● Access to Space: The Future of U.S. Space Transportation Systems

●

●

reliability. An accurate estimate of potential

savings requires a detailed trade-off analysis

for each payload. Achieving these savings will

probably require giving spacecraft program

managers, and those who establish mission and

spacecraft requirements, incentives crafted specifically for the purpose, and may require

developing new launch vehicles.

Lightsats: If allowed to be less capable, reliable, or long-lived, payloads could be both

lighter and less expensive. Useful functions

such as communications and weather surveillance could be performed by payloads small

enough to be launched on small rockets from

airborne or mobile launchers.

Small, simple, and relatively inexpensive

civil and military satellites have been, and still

are, launched at relatively low cost on small

launch vehicles or at even lower cost, sometimes for free, as “piggyback” payloads on

larger launch vehicles. DoD is considering

whether the increased survivability and responsiveness such spacecraft could provide would

compensate for possible decreased capability.

A swarm of several small satellites might

accomplish a given mission as well as a single

large one, and, in many cases, would also be

cheaper because smaller satellites typically

cost much less per pound than do large ones.

Even if the satellites are launched individually,

which would increase total launch cost, overall

mission cost could be lower.

Microspacecraft: Spacecraft weighing only a

few pounds could perform useful space science

missions and might be uniquely economical for

experiments requiring simultaneous measurements (e.g., of solar wind) at many widely

separated points about the Earth, another

planet, or the Sun.

Each type of spacecraft-fatsat, lightsat, or microspacecraft--would impose unique launch demands. New, large, heavy-lift launch vehicles would

be needed to launch the heaviest satellites. Lightsats

could be launched on existing launch vehicles, but

new, smaller launch vehicles might launch them

more economically. In wartime, small launch vehicles could be transported or launched by trucks or

aircraft to provide a survivable means of space

launch. Microspacecraft could be launched on existing launch vehicles, but they might eventually be

launched by more exotic means such as a ram

accelerator, railgun, coilgun, or laser-powered

rocket (see ch. 7). Within the next decade, experiments now being planned may establish the feasibility of some of these launch systems. Their costs

cannot be estimated confidently until feasibility is

proven. However, they may prove more economical

than conventional rockets for launching microspacecraft at high rates.

If Congress wishes to promote spacecraft cost

reduction and, thereby, reduce the cost of space

programs:

1. Congress could order a comprehensive study of

how

by:

●

●

●

●

●

much the Nation could save on space programs

designing payloads to reserve more weight and

volume margin on a launch vehicle;

allowing payloads to be heavier, less capable,

shorter-lived, or less reliable;

designing standard subsystems and buses for

use in a variety of spacecraft;

designing spacecraft to perform single rather

than multiple missions; and

using several inexpensive satellites instead of a

single expensive one.

Lockheed completed such a study in 1972;10 a

new one should consider current mission needs and

technology. It would complement the Space Transportation Architecture Study (STAS) and more

recent and ongoing studies11 that compare space

transportation options but not payload design options.

As noted above, to estimate potential savings

accurately, a detailed trade-off analysis must be

done for each payload, or more generally, for each

mission. So, for greater credibility,

2. Congress could require selected spacecraft

programs-for example, those that might require a

new launch vehicle to be developed-to award two

design contracts, one to a contractor who would

~tikhd ~ssiles & Space CO., Impact of Low Cost Refirbishable and Standard Spacecraji Upon Future NASA Space programs, N72-2~9~3

(Springfield, VA: National Technical Information Semice, Apr. 30, 1972).

llE,g., tie ~r Fomts &r Force-Focu@ STAS, NASA’S Next Manned Space Transportation System study, the Mfens Scie= ~md’s Nation~

Space Launch Strategy study, and the Space Transportation Comparison study for the National Aero-Space Plane Program.
Chapter 6-Reducing Space System Costs ● 63

consider the unconventional approaches mentioned

above.

3. Congress could require both the Department of

Defense and NASA to refrain from developing a

spacecraft if the expected weight or size of the

spacecraft, together with its propellants, upper stage,

and support equipment, would exceed some fraction

of the maximum weight or size that its intended

launch vehicle can accommodate. Public Law 100-

456 requires the Department of Defense to require at

least 15 percent weight margin in fiscal year 1989.12

New legislation could extend this restriction to

NASA and could require size margins in future

years.

In addition, Congress could promote the development of launch systems capable of launching small,

inexpensive spacecraft at low cost or heavy spacecraft with generous weight margins.

INNOVATION AND THE

U.S. TECHNOLOGY BASE

Building a new system, or even making substantial modifications to existing launchers, requires a

vigorous private sector, well-supported research

programs, a cadre of well-trained engineers, and an

institutional structure capable of putting a vast

variety of technologies to use in innovative ways.

According to several recent reports, our existing

space technology base has become inadequate in

recent years.

13 Yet a strong technology base is an

investment in the future; it provides insurance that

the United States will be able to meet future

technological challenges.

Government Programs

Several studies have recommended greater attention to improving the Nation’s technology base for

space transportation.14 Though specific proposals

differ in detail, these studies have cited propulsion,

space power, materials, structures, and information

systems as areas in need of special attention.

In response to these and other expressed concerns,

NASA and the Air Force have initiated four programs to improve the Nation’s launch system

technology base (box 6-B). As currently organized,

these programs are directed primarily toward developing new, advanced capabilities. In the existing

budgetary climate, it may be more realistic to

redirect funding toward technologies that could

be used to improve existing launch systems and

make them more cost-effective to operate. Each of

the three ALS prime contractors are exploring ways

to insert technology conceived in the ALS program

into existing launch systems.

Although launch operations and logistics are

labor-intensive and therefore expensive compared to

manufacturing or materials, launch system designers

have focused little attention on technologies that

would reduce these costs. NASA’s technology

programs are addressing issues in automation and

robotics, technology areas that could significantly

reduce launch operations costs. However, to date

NASA has spent relatively little on applying these

technologies more effectively to Shuttle launch

operations. In the yearly budget process, when

budgets are cut, technology programs tend to be cut

more sharply than operational programs because

they focus on future efforts, rather than near-term

results. Launch operations is the direct focus of

about 30 percent of the ALS program. Outside of this

effort, however, no well-organized or well-funded

plan exists to apply the technologies developed in

these programs to launch operations procedures, or

to coordinate research being carried out through the

existing technology R&D programs.

It may be appropriate to institute a long-term

National Strategic Launch Technology Plan that

would set the agenda for developing and incorporating new technologies into existing and future

launch systems. It should include work in all

development phases:

. broad technology exploration (basic research);

. focused research leading to a demonstration;

and

● implementation to support specific applications.

Even if specific applications have not been identified, the United States needs to fund basic and

W+X S. Rep;. 100-326, p. 36, and H. Rept. 100-989, p. 282.

lqNation~ Re%a~h Comcll, &ronautlcs and space Engineefig Board, space Technology tO ~eet Fu/~e Need (w&$hhlgtOIl, ~: Nationa l

Academy Press, December 1987); Joint DoD/NASA Steering Group, National Space Tramportafion a~support St@, SWTUIMIY RePofl~ MaY 14J

1986,

lqIbid.
64 ● Access to Space: The Future of U.S. Space Transportation Systems

Box 6-B--Technology Development Programs

• Advanced Launch System (ALS) Focused Technology Program—A joint program between NASA and the Air

Force, carried out as an integral part of the ALS Demonstration/Validation Program. Its aim is to pursue research

on specific technologies of interest to the development of an ALS. The program’s contribution to crew-carrying

capabilities will be limited, but important. As much as possible, ALS program managers have deliberately

targeted their research at generic space transportation issues, in order to develop a broad technology base for

designing an ALS. The ALS program plans to spend most of its fiscal year 1991 budget of $125.3 million on

focused technology development.

• Civil Space Technology Initiative—A NASA program designed to revitalize “the Nation’s civil space technology

capabilities and enable more efficient, reliable, and less costly space transportation and Earth orbit operations.

Funding for fiscal year 1990 is $123.8 million (1991 request-$ 171.0 million).

. National Aero-Space Plane—A DoD/NASA program to develop an aerospace plane capable of reaching orbit

with a single propulsion stage. Although this program does not have the specific focus of improving the Nation’s

technology base, some of the technology under development necessary for building the NASP, particularly new

materials and structures, new propulsion techniques, new computational techniques, and methods of handling

liquid and slush hydrogen, will find application elsewhere. The NASP Joint Program Office is spending $150

million over a 30-month period on materials development alone.

. Pathfinder-A NASA program especially directed at technologies for future human space exploration. Very few

of this program’s technologies will be usdful for Earth-to-orbit transportation, as it is directed primarily toward

cm-mbit and interplanetary transportation and life-support issues. Congress appropriated $26.9 million for

Pathfinder in fiscal year 1990. The Administration has requested $179.4 million-a 567 percent incease--in

fiscal year 1991 to prepare for lunar and Martian exploration.

~N@~~ ~mutics ~~ sp~c~ Administration, Office of Aeronautics and Space Tecbdow, 4*CSTI meficw.” APril 19$8.

SOURCE: Office of TechnOlOW Assessment, IW.

focused research in order to build an adequate base of the technology. It will continue to determine

for future applications. launch specifications and provide most of the

funding. Government control of systems involving

The Private Sector’s Role

crews in space will continue, in large part because

such systems are costly and represent a major

In space transportation, the private sector now national commitment.

serves primarily as contractor for Governmentdefined needs. It is just beginning to act as a Harnessing industry’s innovative power in a

commercial service provider.l5 Two firms launched more competitive environment could lead to

their first commercial payloads in 1989.16 reduced launch costs and more effective use of

U.S. resources for outer space. By promoting

Private firms are unlikely to develop major new private sector innovation toward improving the

launch systems until well into the next century design, manufacture, and operations of launch sysunless Congress and the Administration set a high terns, the Government could reduce the cost of

priority on involving them more directly in setting Government launches, yet relatively few incentives

the terms of space transportation development.17 to involve private firms exist today. As a result,

The Government controls access to spacel8 and most firms have spent little of their own money on R&D

15The Dep~ment of Transportation regulates the private launch industw.

16McDonne]l Douglas (Delta) and Martin Marietta (Titan)

ITThe NASP Progm, for ~xample, has sent a high priority on directly invo]ving private firms and the universities in materials and other advanced

research on the X-30.

IBAccording to the 1967 Treaty on Outer Space, which the United states signed, and to which it adheres, “States parties to the Treaty shall bear

international responsibility for national activities in outer space . . . whether such activities arc carried on by governmental agencies or by

non-governmental entities. . .“ The Commercial Space Launch Act oj 2984, which sets out the basic provisions regulating the commercial launch

industry, recognizes this responsibility by stating,”. . . the United States should regulate such launches and services in order to ensure compliance with

international obligations of the United States . . .“
Chapter 6--Reducing Space System Costs . 65

to improve the capability of launch systems or

reduce their costs.

If outer space becomes a more important arena for

private investment, competitive pressures will provide the incentives for launch system innovation.

For the near term, however, incentives must come

from the Government because projected future

demand for commercial launch services is extremely

small compared to Government demand.l9

Incentives could include:

●

●

●

direct grants to develop new technology for

launch systems specifically directed toward

saving costs rather than increasing performance;

cash incentives to firms for reducing the

manufacturing costs of specific items procured

by the Government;20

encouragement of industrial teaming arrangements in focused technology areas such as the

National Aerospace Plane Materials Consortium (see ch. 7).

In addition, the U.S. Government could stimulate

the private sector’s innovative creativity by issuing

a request for proposal for launch systems or services

similar to the Advanced Launch System, and have

industry bid for them. Such an approach assumes

minimum Government oversight over the design

and manufacturing processes. It would also require

the aerospace community to assume much greater

financial risk than it has taken on in the past. In order

to offset that risk, the Government might have to

agree to a minimum purchase that would allow the

companies involved to earn a profit on their investment

Finally, America’s ability to foster the innovative

process depends directly on having an adequate

supply of scientists and engineers. In order to assure

that the United States has sufficient trained personnel to contribute to the development of new launch

systems and other space activities, the Government

could strengthen its support for science, mathematics, and engineering education from grade school

through graduate school.21

1$’Rjch~d 13rack~n, Space challenge ‘88,” Fourth Annual Space Symposium Proceedings Report (Colorado Springs, CO: U.S. Space Foundxion

1988), pp. 76-79,

ZOFa exaple, Rockwell International ewns 20% of every dollar it saves NASA on building orbiterOV-105.

21u.s. Congress, Office of Technology Assessment, Educating Scientists and Engineers Grade School to Graduate SchOl, OTA-SET-377

(Washington, DC: U.S. Government Printing Office, June 1988).
Chapter 7
Chapter 7

Potential Future Launch Systems

The Space Transportation Architecture Study

(STAS)l and later studies conducted by NASA and

the Air Force identified a wide range of technologies

and management practices that could reduce the

costs of space transportation and also increase

reliability and operability. This chapter describes

several options for meeting future space transportation demand.

CARGO ONLY

The Nation’s existing fleet of expendable launch

vehicles (ELVs) can carry payloads weighing up to

39,000 pounds (figure l-l) to low Earth orbit (LEO).

Eventually, as cargoes gradually increase in size and

weight, and as the Nation seeks to do more in space

than it currently plans, new launch systems offering

higher lift capacity will become attractive, if they

can reduce costs while improving reliability and

operability.

Some have argued that the Nation needs a

heavy-lift launch vehicle (HLLV), similar in capacity to the Soviet Energia, 2 which can lift about

220,000 pounds to LEO. Indeed, for tasks requiring

the launch of many pounds of cargo to space at one

time in a single package, an HLLV would be

necessary. If available, an HLLV would be useful for

building large space structures, such as the Space

Station, because launching pre-assembled structures

would obviate much risky and expensive on-orbit

assembly.

Some also argue that if the United States had an

HLLV, the Government and the private sector would

find a way to use it, for example, in bringing down

launch and payload costs. OTA’s analysis of future

space transportation costs indicates that average cost

per pound can be reduced substantially only if there

is a marked increase in demand—that is, the number

of pounds launched per year. Unless the Nation

plans to increase investment in space activities

significantly over current levels, development of an

HLLV in order to reduce launch costs appears

unwarranted.

Box 7-A—Potential Uses for Shuttle-C

. Space Station Support--Shuttle-C could reduce

both the number of launches required to assemble

the planned Space Station and the extravehicular

work in space required to assemble and outfit the

station.

● Science and Applications Payloads-Shuttle-C

could launch large, heavy platforms for missions

to planet Earth, and for the planetary sciences,

astrophysics, and life sciences disciplines. If

launched on the Shuttle, equivalent platforms

might require on-orbit assembly by human crews.

. Technology Test Bed --Shtttde-C could be used

to test new or modified systems, such as liquid

rocket boosters, or new engines.

● National security Applications --Shuttle-C could

place large payloads into polar orbit from Cape

Canaveral, and Vandenberg Air Force Base.l It

could place large payloads into retrograde orbits

from Vandenberg Air Force Base.

IIf the Shuttle launch complex (SLC-6) at Vandenberg ~B

were reactivated.

SOURCE: Adaptedfiom NASA Marshall Space Center, ’’ShuttleC Users Conference, Executive Summary,” May

1989.

As noted earlier, if the Nation were to pursue the

goals of building a permanent settlement on the

Moon and/or sending explorers to Mars, one or more

HLLVs would be required to carry the requisite fuel

and other support infrastructure to LEO (box 7-A).3

Shuttle-C

NASA has investigated the potential for building

a cargo-only HLLV, which would use Shuttle

elements and technology. As envisioned by NASA,

Shuttle-C could launch between 94,000 and 155,000

pounds to low Earth orbit (figure 7-1). 4 Such a

system could lift large, heavy payloads if the risk or

cost of using the Shuttle would be high as a result of

IU.S. ~p~ment of Defense and Nation~ Aeronautics and Space Administration, National Space Tramportation LZW’ Support St@ I995-201O,

Summary Report of the Joint Steering Group, May 1986.

2’rhe /7wrgia can Cw ~lther c~go or ~c soviet shuttle into space, Energiu may be u~d to ]ift elements of a new Soviet space station.

sRichmd Tmly, “Testimony ~fore the su~ommlttee on Space Sciences and Applications of the House Committee on !$cience, Space, and

Technology, Sept. 26, 1989; National Aeronautics and Space Administration, Report of the 90-Day Study on Human Exploration of the Moon & Mars,

November 1990.

dshu~]e is Cumendy capable of lifting 52,()(XI pounds to 110 nautical miles above Kennedy SPace Center.

7 0
70 ● Access to Space: The Future of U.S. Space Transportation Systems

Figure 7-1—Potential Shuttle-C Performance

Shuttle-C Ascent Performance Capability (lb)

220 nmi

28.5 deg.

BASELINE DESIGN 2 SSME @ 100% 82,750

@ 104% 88,180

3 SSME @ 100% 141,300

@ 104% 145,200

BASELINE + ASRM 2 SSME @ 104% 99,620

3SSME @ I04% 156,600

ETR — ---

110 nmi

28.5 deg.

93,700-

99,100

151,100

155,000

110,540

166,500

110 nmi

98.7 deg.

n/a

n/a

53,200

57,200

13,900

68,600

KEY: ETR Eastern Test Range (Cape Canaveral); Test Range (Vandenberg Force Base)

WTR

30x200nmi 110 nmi

28.5 deg. 98.7 deg.

105,900 57,460

112,40 62,800

162,900 111,000

167,400 115,100

124,400 74,300

179,400 126,400

SOURCE: National & Space Administration, 1989.
Chapter 7-Potential Future Launch System ● 71

“orbital assembly or multiple Shuttle launches.”5

For example, it could enable the launch of large

elements of the planned Space Station, already

outfitted, reducing the risks that are associated with

extensive on-orbit assembly using the Shuttle, or the

Shuttle plus smaller ELVs (box 7-A).

Because the Shuttle-C would use most of the

subsystems already proven on the Shuttle, NASA

asserts that the Shuttle-C would cost about $1.8

billion to develop and could be ready for the first

flight about 4 years after development begins.

NASA planners suggest that it would serve to

“bridge the gap” in launch services for large

payloads between the mid-1990s and the beginning

of the 21st century when an Advanced Launch

System (ALS) could be available.6

Shuttle-C would avoid some costs by using

Shuttle facilities and subsystems. For example, each

Shuttle-C would use and expend two or three Space

Shuttle Main Engines (SSMEs), but it could use

SSMEs that had been used on the Shuttle until

permitted only one more use by safety rules; these

would be almost completely depreciated. However,

Shuttle-C planners now propose to use SSMEs that

have been used on the Shuttle only once; they would

cost the Shuttle-C program $20 million each if they

can be procured for $25 million each (versus $38

million currently) and refurbished for $15 million

(fiscal year 1991 dollars), and if half the cost of two

flights is allocated to Shuttle-C. In this case, the

incremental cost per launch would be about 480

million fiscal year 1991 dollars7 for a 3-engine

Shuttle-C.8

Advanced Launch System (ALS)

In 1987 the Air Force and NASA began preliminary work on the (ALS), with the goals of dramatically reducing launch costs and improving vehicle

reliability and operability. ALS program officials

expect the ALS efforts to result in a modular family

of cargo vehicles that would provide a broad range

of payload capacity (figure 7-2). The ALS program

estimates that development would cost about $7.3

billion (1989 dollars),

about $4 billion.

The ALS approach

performance efficiency

bility by incorporating

and facilities would cost

is to trade launch vehicle

for low cost and high reliadesign and operating margins, and using redundant subsystems that are highly

fault-tolerant. In addition, ALS designs would

simplify and standardize interfaces, manufacturing

processes, and operations procedures. New technologies would be developed and used only if they

would further the goals of low cost and high

reliability. ALS managers expect these approaches

to improve the operability of the ALS compared to

existing launch systems, by providing:

. high availability and reliability;

. high throughput and on-time performance; and

● standard vehicle-cargo operations

The ALS Program Office has defined a reference

vehicle using liquid propulsion and capable of lifting

between 80,000 and 120,000 pounds to LEO. It

would use low-cost, 580,000-pound thrust engines

that would be developed specifically for the ALS.

The ALS program is also exploring the possible use

of solid rockets for strap-on boosters.

Recent] y, the Department of Defense decided not

to proceed with procurement of an ALS at this time,

but to continue the program as a technology

development effort. The primary thrust of the

restructured ALS program would be to develop a

new engine and other critical technologies for an ALS

family of vehicles that could be started later in the

decade if the need for such vehicles arises. The

technology and subsystems developed for the ALS

technology development program could provide the

basis for building an HLLV system, if needed, in the

early part of the 21st century. In the meantime, the

program could provide important improvements for

existing ELVs (table 7-l).

SNASA Mti~l Space Center, “Shuttle-C Users Conference, Exeeutive SumIIMY,” MaY 1989.

%id.

TAbout 424 million fiscal year 1989 doik.

8’rhe o~er ~f of~e cost sho~kj ~ ~lo~ated t. Shuttie Owrations. oTA’s cost estimates for Shunle ~s~e 10 or more ws per SSME. StX U.S.

Congress, Office of Technology Assessment, L.uunch Optkxr for the Future.” A Buyer’s Guide, OTA-lSC-383 (Washington, DC: U.S. Government

Printing Office, July 1988), p. 68, footnote 5.

9ALS PI-Owam Office bnefmg to OTA, September 1989.
72 ● Access to Space: The Future of U.S. Space Transportation Systems

400

300

200

100

0

Payload

Figure 7-2—Advanced Launch System: The ALS Famiiy

Height in feet

I n

I Reference vehicle / \

40 tO 80 40 to 80 80 to 110 100 to 251 80 to 120 120 to 300

(thousands of Ibs)

Booster:

Type Stage & half ALS-SRM SRMU STS LRB ALS LRB ALS LRB

Propellant L 02

/ L H2 Clean solid Clean solid L o2

/ L H2 L 02/ L H2 L 02

/ L H2

Number N/A 3 to 8 2 to 4 2 to 6 1 2 to 4

KEY: ALS . Advanced Launch System; LRB = Liquid Rocket Booster; SRM = Solid Rocket Motor, SRMU = Solid Rocket Motor Unit; STS = Space

Transportation System. -

SOURCE: Advenced Launch System Program Office.

Unconventional Launch Systems

A number of launch systems have been proposed

that would use “exotic” technologies to propel

payloads into space. For example, a payload might

ride to orbit on a plastic cylinder, the bottom of

which is heated from below by the beam from a

powerful ground-based laser. As the plastic on the

bottom decomposes into vapor and expands, it will

exert pressure on the cylinder, producing thrust. The

SDIO estimates development and construction of a

laser for launching 44-pound payloads would require about $550 million over 5 or 6 years. It

estimates that a laser system could launch up to 100

payloads per day—more than 20 Shuttle loads per

year-for about $200 per pound, assuming propulsive efficiencies 300 percent greater than those

achieved in lab tests. The cost would be closer to

$500 per pound if efficiency is not improved.

Railgun proponents predict a prototype railgun

capable of launching 1,100-pound projectiles carrying 550 pounds of payload could be developed in

about 9 years for between $900 million and $6

billion, including $500 million to $5 billion for

development of projectiles and tracking technology.

If produced and launched at a rate of 10,000 per year,

the projectiles (less payload) might cost between

$500 and $30,000 per pound (estimates differ). The

cost of launching them might be as low as $20 per

pound -—i.e., $40 per pound of payload.l0

Several other gun-like launchers have been proposed. One is the ram cannon (or ram accelerator),

the barrel of which would be filled with gaseous fuel

and oxidizer. The projectile would fly through this

mixture, which would be ignited by the shock wave

of the passing projectile and would exert pressure on

it, accelerating it. A ram cannon designed for space

launch would be about 2 miles long.

Many uses have been proposed for such launch

systems, but to date only the Strategic Defense

Initiative Organization has identified a plausible

10NOE, however, that such rates are more than 100 times the current launch rate.
Chapter 7—Potential Future Launch Systems . 73

Table 7-l—Potential ALS Technology

Improvements to Existing Systems

Propulsion

● Simplified engine designs

. Low cost manufacturing processes

● Low cost, dean solid propellants

. Automated nondestructive testing for solid rocket motors

. Enhanced liquid propulsion performance

Avionics and software

● Highly reliable avionics

● Weather and mission adaptive guidance, navigation, and

control

. Expert systems for vehicle/mission management

● Automated software production

● Electromechanical actuators

Aerothermodynamica

● Engine and avionics reuse

— recovery

— landing

— maintenance

— reentry systems

Structures, materials, and manufacturing

● Low weight materials for propellants

. Composite structures for shroud and innertank

. Low cost manufacturing

— automation: welding

— processes: spinning, casting, extrusion, forging

Operations

. Automated checkout and launch operations

. Paperless management

. Expert system monitoring and control

. Engine and avionics health monitoring

. Operational subsystems

— pyrotechnic alternatives

— hazardous gas detection

— remote cable transducer

SOURCE: Advanced Launch System Program Office,

demand for high-rate launches of microspacecraft,

which could use such systems economically. However, demand for launches of scientific, commercial,

and other microspacecraft could increase, perhaps

dramatically, if launch costs could be reduced to a

few hundred dollars per pound.

Most of these exotic launch technologies are still

in the exploratory stage and therefore much less

mature than rocket technology. Because of this, the

costs cited must be regarded as highly speculative.

Nevertheless, Congress may wish to fund continued

research in order not to foreclose the opportunity

exotics may pose for reducing future launch costs,

especially for extremely small payloads such as the

microspacecraft discussed in chapter 6--Reducing

Space Space System Costs.

CREW-CARRYING LAUNCH

SYSTEMS

Even if the Shuttle is made more reliable, the

Shuttle% high operational costs will eventually

lead to a decision to replace it with a successor

capable of more effectively fitting the needs of the

Government’s activities for people in space and

reducing the recurring cost of launching piloted

vehicles. The most important goal of each Shuttle

mission is to return the reusable orbiter and crew

safely to Earth.11 This goal, an essential aspect of

flying human crews and an expensive reusable

vehicle, nevertheless adds to mission costs by

requiring additional attention to payload integration,

extra payload safety systems, and additional preflight payload handling. In addition, humans require

special environments not needed by many payloads.

For the 1990s, the primary need for transporting

people to and from outer space will be to operate the

Shuttle orbiters and experiments aboard them, and to

assemble and operate the Space Station. NASA now

estimates that Phase I Space Station construction

will require 29 Shuttle flights (including some

logistics flights) and about 5.5 flights per year

thereafter to service Space Station. If the Nation

decides to build a lunar base or to send a crewcarrying mission to Mars, NASA estimates that

additional crew-carrying capacity would be needed

to supplement or replace the Shuttle.

NASA is studying several launch concepts that

could supplement or replace the current Shuttle.

Most could not be available before the turn of the

century. NASA and the Air Force are collaborating

on the development of an aerospace plane using

advanced, airbreathing engines that could revolutionize spaceflight. However, even if development

were pushed, an aerospace plane based on airbreathing technology is unlikely to be available for

operational before 2005.

PERSONNEL CARRIER

LAUNCHED ON UNPILOTED

LAUNCH VEHICLES

NASA is exploring the possibility of developing

a personnel launch system (PLS) that would use a

1 IReturning tie orbi~r and crew stiely is not necessarily equivalent to completing the mission, although it is often confused with the s~e. NASA

will abort the mission rather than knowingly risk crew safety, if problems appear. Launching payloads on unpiloted vehicles avoids the added complexity

and cost provided by the human factor.
74 ● Access to Space: The Future of U.S. Space Transportation Systems

small reusable glider, capsule, or lifting body

launched atop an expendable launch vehicle rated to

carry crews.

12 This option would separate human

transport from cargo delivery, and could, in principle, be made safer than the Shuttle. The Soviet

Union, 13 The European Space Agency,14 and

Japan]5 have all adopted this approach to placing

people in orbit. Candidate launchers could include a

Titan III, a Titan IV, a Shuttle-C, or perhaps a new,

as-yet undeveloped launcher such as the ALS.

The ALS Joint Program Office has recognized the

potential benefit of having a flexible launch vehicle

rated for launching crews. It has therefore required

that contractor proposals for an ALS provide for a

launch vehicle capable of meeting both the design

and quality assurance criteria for carrying crews.

Designing an ALS launch vehicle at the outset to

provide additional structural strength would be

much less expensive than redesigning, rebuilding,

and retesting it after it is developed. ’b As currently

envisioned, ALS would also provide previously

unobtainable levels of safety by incorporating faulttolerant subsystems and engine-out capability.

Having a crew-rated automated launcher in addition to a Shuttle has three strong advantages: 1) the

crew-rated vehicle could launch new orbiters designed for launch with other boosters; 2) it could

enhance crew safety (intact abort is a design

requirement for the PLS); and 3) there may be cases

where it will be necessary only to deliver personnel

to the Space Station. In that case, there is no need to

risk a Shuttle orbiter. Separation of crew- and

cargo-carrying capabilities is especially important,

as carrying both on the same vehicle adds to the

payload costs and may reduce crew safety, In view

of the concerns over Shuttle fleet attrition, it may

be important for NASA to investigate the potential for using a crew-rated ALS or other launcher

to reduce the risk of losing crew-carrying capacity early in the next century.

Advanced Manned Launch System (AMLS)

NASA’s program investigating the set of concepts for an AMLS, previously called the Shuttle II,

is studying new designs with the goal of replacing

the Space Shuttle early in the next century. A vehicle

significantly different from the existing Shuttle

would result (box 7-B). If activities involving crews

in space increase markedly in the next century, an

AMLS using advanced technology might be needed.

It could offer significant improvements in operational flexibility and reduced operations costs over

the existing Shuttle. However, development, testing,

and procurement of an AMLS fleet could cost $20

billion or more (1989 dollars).

The timing of the development phase for an

AMLS should depend on NASA’S need to replace

the Shuttle fleet. It would also depend in part on

progress reached with technologies being explored in the Advanced Launch System and

National Aero-Space Plane (NASP) programs. In

any event, a decision on AMLS will not have to be

made for several more years. For example, if

Congress decided that an operational AMLS was

needed by 2010, the decision to start the early phases

of development would have to be made by about

1995. By that time, Congress should have had

adequate opportunity to assess the progress made in

the NASP program (see below), which could be

competitive with an AMLS.

An Aerospace Plane

Developing a reusable vehicle that could be

operated like an airplane from conventional

runways, but fly to Earth orbit powered by a

single propulsion stage would provide a radically

different approach to space launch and a major

step in U.S. launch capability. However, building

such a vehicle poses a much larger technical

challenge than building a two-stage, rocketpropelled vehicle such as the AMLS. A successful

aerospace plane might also provide greater benefits

to industry and to U.S. technological competitiveIZA NASA or Air Force la~ch vehicle is said to be crew, or “man-rated,” if it hm been certfied as meeting certain safety criteria. These include design

criteria as well as quality assurance criteria.

IsAlthough the Soviet Ufion has also developed a shuttle orbiter similar to the us, Space shuttle, it will cont~ue to rely on its &?JU4Z Vt5hiCk fOr

transporting people to the Mir space station atop the Proton launcher, and on its Progrr.ss transport for launching cargo.

lqThe reusable, pilot~ Hermes spacep]ane Wi]] be launch~ atop an Ariane V ]a~ch~.r sometim~: in the late l~s. Ariane V is currently dso under

development.

]5Jap~ plan5 t. deve]op a ~~1, ~pi]ot~ spacep]ane, HC)PE, that would be launched atop its H 11 launch vehicle, now ~der deve@ment. HOpE

may experience its first flight in the early years of the next century.

161t wo~d, however, add a small amount to the cost of each flight in which cargo Only were carri~.
Chapter 7---Potential Future Launch Systems ● 75

Box 7-B—The Advanced Manned Launch

System (AMLS)

The goal of the NASA AMLS program is to

define advanced manned launch system concepts,

including their development, system and operational characteristics, and technology requirements.

A vehicle significantly different from the existing

Shuttle would result. NASA is presently evaluating

five concepts:

. an expendable in-line two-stage booster with a

reusable piloted glider;

. a partially reusable vehicle with a glider atop

a core stage;

. a partially reusable drop-tank vehicle similar

to the fully reusable concept below but with

expendable side-mounted drop tanks;

. a fully reusable rocket with a piloted orbiter

parallel-mounted (side-by-side) to an unpiloted glideback booster;

. a two-stage horizontal takeoff and landing

air-breather/rocket, which would be fully reusable.

Critical technology needs for all AMLS concepts

include:

. light-weight primary structures,

● reusable cryogenic propellant tanks,

● low-maintenance thermal protection systems,

. reusable, low-cost hydrogen propulsion,

Ž electromechanical actuators,

. fault tolerant/self-test subsystems, and

. autonomous flight operations.

SOURCE: National Aeronautics and Space Administration.

ness than an AMLS, as a result of the development

of new materials and propulsion methods. The

Department of Defense and NASA are jointly

funding the NASP program to build the X-30 (box

7-C),17 a research vehicle intended to demonstrate

both single-stage access to space and endoatmospheric hypersonic cruise capabilities.

NASP is a high-risk technology development

program. Building the X-30 to achieve orbit with

a single stage would require major technological

advances in materials and structures, propulsion

systems, and computer simulation of aerody -

Box 7-C-The National Aero-Space Plane

Program (NASP)

NASP is a program to build the X-30, an

experimental, hydrogen-fueled, piloted aerospace

plane capable of taking off and landing horizontally

and reaching Earth orbit with a single propulsiom

stage. The design of the X-30 would incorporate

advanced propulsion, materials, avionics, and control systems and make unprecedented use of supercomputers as a design aid and complement to

ground test facilities. NASP is a technically risky

program that, if successful, could spur the development of a revolutionary class of reusable, rapid

turn-around hypersonic flight vehicles, that would

be propelled primarily by air-breathing “scramjet”

engines.

Operational follow-ons to the X-30: An aerospace plane derived from NASP technology offers

the promise of dramatically reduced launch costs if

the vehicle can truly be operated like an airplane

using standard runways, with minimum refurbishing and maintenance between flights.

SOURCE: Office of Technology Assessment, 1990.

namic and aerothermal effects from Mach 1 to

Mach 25.18 The uncertainties in meeting design

goals are compounded because a successful X-30

would require many of the key enabling technologies to work in concert with one another. Because

ground test facilities cannot replicate all of the

conditions that would be encountered in ascent to

orbit, it is impossible to predict precisely how the

X-30 would perform when pilots make the first

attempts to push it far into the hypersonic realm.

If funded, the X-30 would be a research vehicle,

not a prototype of an operational vehicle. To develop

an operational vehicle would require an additional

program beyond NASP. A development cycle that

took full advantage of lessons learned in the X-30’S

planned test program could not commence until the

late 1990s at the earliest. An operational vehicle

derived from the proposed X-30 would therefore be

unlikely until approximately 2005 or later unless it

were closely modeled on the X-30. However, if the

X-30 were designed to provide the maximum data — . —

17 Debates over NASP f~ding within the Administration and within Congress have left !he long-term status of the program in doubt. ~ SPriW 1989

DoD decided to cut its contribution to NASP by two-thirds for fiscal year 1990 and to terminate funding for it in subsequent years. A reexamination

of the program by the National Space Council led 10 the replacement of program funds, but delayed the decision concerning whether or not to proceed

with construction of the X-30 for2 years, to 1993. Congress decided to appropriate $254 milhon for NASP research in 1990 ($194 from DoD; $60 million

from NASA).

IsMach 1 is the speed of smnd. Hypersonic usually refers to flight at speeds of at least Mach 5—tive times the speed of sound, or about 4,~ miles

per hour. Mach 25 (25 times Mach 1), is the speed necessary to reach Earth orbit.
76 ● Access to Space: The Future of U.S. Space Transportation Systems

about the feasibility of an operational aerospace

plane, it would be unlikely to serve as an appropriate

prototype of an operational vehicle. Although the

X-30 would be piloted, aerospace planes based on

the X-30 could be designed to carry cargo autonomously. 19

If the X-30 proves successful, the frost operational

vehicles that employ NASP technologies are likely

to be built for military use, possibly followed by

civilian space vehicles. Commercial hypersonic

transports (the ‘Orient Express”) are a more distant

possibility. Recent studies have shown that from an

economic standpoint, commercial hypersonic transports would compare unfavorably with proposed

slower, Mach 3 supersonic transports based on less

exotic technology and conventional fuels. Therefore, the most economic route to commercial

high-speed air transport is unlikely to be through

the X-30 development program. However, the

X-30 program could provide technical spin-offs

to aerospace and other high-technology industries through its development of advanced materials and structures and through advances in

computation and numerical simulation techniques. It is too early to judge the economic

importance of such spinoffs.

Even assuming a rapid resolution of the myriad of technical issues facing the creation of an

X-30 capable of reaching orbit with a single

propulsion stage based on airbreathing technology, translating this technology into an operational spaceplane might come late in the period

when an AMLS could be ready, and perhaps

after the time when replacements for the Shuttle

would be necessary. With their less exotic technologies, rocket propelled AMLS vehicles could probably be funded in the mid to late 1990s and still be

developed in time to replace aging Shuttles. An

AMLS program begun in this period would also

benefit from the technical base being developed in

the NASP program, which is exploring concepts

based solely on rocket propulsion as well (see

below). However, the technical and economic

uncertainties of both programs suggest that

Congress would benefit from monitoring their

progress and comparing the probability of success of each before committing development

funds for operational vehicles in the mid-1990s.

The development costs of each program, as well

as other competing budget priorities, will play a

major role in such a decision.

Additional Reusable Launch Concepts

Routine flight to space with reusable vehicles

offers tremendous economies if the United States

can master the underlying technologies-materials,

structures, propulsion, and avionics to produce a

highly reliable and maintainable reusable vehicle.20

The technologies needed for fully reusable space

launch systems are being developed primarily by the

NASP program, although the ALS and AMLS

programs are also investing in reusable concepts.

Future operational cargo systems may combine the

best technologies developed by each program.

Ranging from rocket-powered vehicles that might be

available by the beginning of next century, to

airbreathing propulsion systems that would be

available later, such vehicles could support intermediate to near Shuttle-size payloads. Operated as fully

reusable vehicles able to fly to orbit without an

expendable stage, such vehicles offer some of the

economies associated with aircraft.

l~e Soviet shuttle B~an has demonstrated the feasibility of launching and landing a reusable space plane without a human cnw.

z~ee app. A for a discussion of the effect of reliability on life-cycle cost estimates of future launch systems.
Chapter 8

International Competition

and Cooperation

Photo credit: Novosti

Soviet Shuttle Buran on the launch pad at the Soviet launch complex
Chapter 8

International Competition and Cooperation

COMPETITION

This decade has seen the rise of intergovernmental

competition in space transportation. The development of space transportation systems is a national

achievement that signals a nation’s status as a space

power, able to develop and use advanced technology. The Soviet Union, Europe, Japan, and China

now operate launch systems capable of reaching

space with sizable payloads. Although only the

United States and the Soviet Union are currently

able to send humans to and from space, ESA, France,

Germany, Japan, and the United Kingdom are all in

various stages of developing their own reusable

launch systems, which, if successful, would be

capable of transporting human crews.

Recently, commercial competition subsidized by

governments has become an important part of space

transportation competition. Europe, the Soviet

Union, and China now compete with U.S. private

firms for the international space launch market. Each

government has developed its own mechanisms for

assisting its launch fins. For example, Glavcosmos

(U. S. S. R.) and the Great Wall Corp. (China) are

government corporations, for which sales of launch

services are an integral part of international policy.

Arianespace, S.A. (France) is a private corporation

owned in part by the French Governmental Although

it operates as a private firm, Arianespace receives

considerable indirect support from the European

Space Agency, which has developed the various

Ariane launchers, built the launch complexes, and

purchases launch services. The United States Government has assisted U.S. private firms by developing the expendable launch vehicles and launch

facilities (which are leased to the firms), by purchasing launchers and launch services from them, and in

numerous other ways.2

A number of experts have raised doubts about the

capability of the U.S. private sector to compete for

providing launch services in the world market,

especially in the face of a relatively small market for

commercial launch services. Projected launch services supply far exceeds expected demand. Launch

firms in the United States, France, the Soviet Union,

and China expect to be able to supply about 35 to 40

vehicles per year to launch only 15 to 20 commercial

payloads per year over the next decade.

A launch industry capable of competing on the

basis of price as well as capability in the world

market could contribute several hundred million

dollars per year toward improving the current strong

negative balance of payments with foreign countries, directly by making sales to foreign customers,

and indirectly by keeping U.S. payload owners from

going off-shore to purchase launch services. Congress could assist the U.S. private sector by helping

the Executive work to develop and maintain a‘ ‘level

playing field” in the marketplace, in which prices

are arrived at by rules based on justifiable economic

rationales and agreed on by the launch providers.3

The recent negotiations with China in which that

country agreed to price its launch services to reflect

actual manufacturing and launch cost have been a

step in the right direction, but similar arrangements

need to be negotiated with all launching nations who

are offering their launch vehicles in the commercial

market.

COOPERATION

The United States has always maintained a

vigorous program of international cooperation in

space in order to support U.S. political and economic

goals. However, it has cooperated very little with

other countries in space transportation, in large part

because most launch technology has direct military

applications and much of the technology has been

classified or sensitive.

Today, because other countries have developed

their own indigenous launch capabilities, reducing

much of the competitive edge the United States once

held, and because progress in space will continue to

be expensive, cooperating on space transportation

and sharing costs could be beneficial. Several

cooperative ventures have been suggested:

● Space Station resupply. The United States

could share responsibility for resupply of the

international Space Station with its Space

Station partners. In order for other countries to

l~mespace is owed by 35 companies, 13 banks, and CNES, the French Space Agenc}

z~e ~ommercl~ market done is insufficient t. suppo~ more than one U.S. commercial mcdlum-capacity launch system. NO large launch sYstem

has yet been privately developed, and at least for the next decade or two commercial traffic lcwels will probably not justify future private development.

JS= public Law 1~.657 (lfj2 Stat. 3900), “The Commercial Space Launch Act AJll(?ndt!len[s of 1988.”

-79 -
80 ● Access to Space: The Future of U.S. Space Transportation Systems

Photo credit: British Aerospace

Artist’s conception of British Aerospace’s Hotol aerospace plane taking off. If successful, this space plane

would reach Earth orbit with a single propulsion stage.

use their launch systems to supply the Space

Station, or to dock with it, the countries will

have to reach agreement with the United States

on appropriate standards for packaging, docking, and safety. ESA and NASA have now

established a working committee to discuss

these matters. If successful, such cooperation ●

could be extended to include cooperation on

more sensitive aspects of space transportation.

In particular, because Europe and Japan have

now developed and operated their own launch

systems, they may have specific technologies

or methods to share with the United States in

return for access to some U.S. technology.

● Emergency rescue from Space Station. As

noted in an earlier section, NASA is planning

to provide some sort of emergency crew return

capability for the Space Station. NASA estimates that developing such a capability would

cost between $1 billion and $2 billion, depending on its level of sophistication. If properly

outfitted, the European Hermes or the Japanese HOPE might be used as an emergency

return vehicle. In addition, Hermes could

even back up the Shuttle for limited space

station crew replacement. However, such

international cooperation would also require a

degree of international coordination and technology sharing for which the United States has

little precedent.

Cooperative space rescue efforts. At present,

the Soviet Union is the only country beyond the

United States with the capability to launch

people into space. As Europe and Japan develop their crew-carrying systems, the potential

for emergencies requiring rescue from a variety

of space vehicles will increase. Broad agreements on docking standards, and procedures for

space rescue,4 could increase astronaut safety

for all nations and lead to more extensive

cooperative activities in the future. Initial

meetings have been scheduled this spring to

discuss the nature and extent of such cooperation. Both this cooperative project and the use

of foreign vehicles to supply Space Station

have the advantage that they risk transferring

very little U.S. technology to other participants. 5

 U. S. S. R., have On t& 

and the Return of Objects Launched into Outer 7570; TIAS 6599.

 Program, for example, was designed to minimize for 
Chapter 8--International Competition and Cooperation ● 81

●

●

Aerospace plane research and development.

With strong encouragement from their private

sectors, Germany, Japan, and the United Kingdom are working independently toward development of aerospace planes. The level of

foreign sophistication in certain areas of advanced materials, advanced propulsion, and

aerodynamic computation is on a par with U.S.

work. A joint development program with one or

more of these partners might allow the United

States to develop an aerospace plane faster and

with lower cost to the United States than the

United States could on its own. Although a

joint project would risk some technology transfer, if properly structured, such a joint project

could be to the mutual benefit of all countries

involved.

U.S. use of the Soviet Energia heavy-lift

launcher. The U.S.S.R. has offered informally

to make its Energia heavy-lift launch vehicle

available to the United States for launching

large payloads. As noted throughout this report,

the United States has no existing heavy lift

capability. Thus, the Soviet offer could assist in

developing U.S. plans to launch large, heavy

payloads, such as Space Station components.

However, concerns about the transfer of militarily useful technology to the Soviet Union

would inhibit U.S. use of Energia for such

high-technology payloads. As well, NASA

would be understandably reluctant to make use

of a Soviet launcher because such use might be

seen as sufficient reason for the United States

to defer development of its own heavy-lift

vehicle.

Although cooperation in space transportation can

be expected to be more difficult than cooperation in

other areas of space endeavor, it could assist the

United States to achieve much more in space than

Photo credit: Arianespace

Night launch of Ariane 3 launcher from the European

Space Agency launch pad in Kourou, French Guiana.

this country can afford to attempt on its own.

However, it will require that NASA and the U.S.

aerospace industry make a greater effort to tap the

expertise and technology now available in other

industrialized countries.
Appendix A

The Sensitivity of Operational

Aerospace Plane Costs To Required

Confidence and Actual Reliability
Appendix A

The Sensitivity of Operational Aerospace Plane Costs

To Required Confidence and Actual Reliability

The proposed experimental National Aero-Space Plane

(NASP), the X-30, is being designed with a goal of 99.999

percent reliability—i.e., to have only 1 chance in 100,000

of failing catastrophically during a flight, assuming no

human error. NASP program officials have said that later

first-generation aerospace planes, which they term

NASP-Derived Vehicles (NDVs), would probably be

designed to have a similar reliability. Recognizing that the

design reliability does not account for possible human

error in maintaining and flying the vehicle, NASP

program officials assume the actual reliability of a

first-generation NDV would be lower—nominally 99.8

percent, but 99.9 percent in the “best case, ” and 99.5

percent in the “worst case.”1

NASP program officials assume there is little risk that

an NDV of lower reliability would be flown on operational missions, because they expect NDV development

would be halted if the proposed X-30, or a later prototype

NDV, fails to demonstrate acceptable reliability (99.5

percent) in its flight test program. Thus, in their view, the

cost at risk would be not billions of dollars of greater than

expected failure costs but only those funds spent to

develop and build X-30S.

2

This argument hinges on a critical assumption: that if

the test vehicles turn out to be unacceptably unreliable, the

test program will detect that fact with high confidence.

The validity of this assumption cannot yet be decided,

because the NASP program office has not yet specified

what kind of confidence (statistical or subjective) they

require, nor how much is enough, nor how it will be

calculated from test results. These details are important,

because a test program cannot determine the reliability

precisely. The test flights might be a lucky streak, or an

unlucky streak; the actual reliability could differ significantly from the successful percentage of test flights.

However, a properly designed test program can determine

the confidence level with which the required reliability

has been demonstrated.

In choosing a required confidence level, NASP program officials face a dilemma—as would any manager of

a launch vehicle development program: Requiring too

little confidence could allow acceptance of a vehicle that

is actually unacceptably unreliable; operational vehicles

of similar design and reliability would probably fail often

enough to incur staggering failure costs. If, on the other

hand, too much confidence is required, a vehicle that is

actually highly reliable might be rejected, and the savings

potentially realizable by using operational vehicles of

similar design and reliability would be forfeit.3

NASP program officials must also choose the type of

confidence to require. They could require statistical

confidence to be demonstrated, or they could calculate the

confidence level by Bayesian inference, which would use

the results of the flight tests to update a subjective prior

probability distribution over possible values of reliability

(see box A-A).4 The former choice would require a very

large number of flights to demonstrate the required

reliability with high statistical confidence. 5 A problem

with the latter choice is that there would be risks of

optimism and pessimism. If the prior distribution is

optimistic, the reliability might be low but the vehicle

would be accepted and later losses incurred. If pessimistic, reliability might be high but the vehicle would be

rejected and potential savings unrealized.

Because the type and level of confidence with which

99.5 percent reliability must be demonstrated has not been

specified, and because the actual reliability will never be

known precisely, this appendix shows how the life-cycle

costs of acquiring and operating a mixed fleet of launch

vehicles-including NDVs, if accepted—would depend

on the type and level of confidence required in testing and

on the actual reliability.

Cost Estimates,

If Statistical Confidence Is Required

The type and level of confidence required and the actual

reliability determine the probability that the test program

will be successful; if it is, NDVs will be acquired and

operated, and their actual reliability will affect the failure

costs incurred.

Figure A-1 shows estimates of the probabilities with

which test vehicles of various reliabilities would demonstrate 99,5 percent reliability with various levels of

statistical confidence in 100 test flights. If 40 percent

~NASp Joint progam Office staff, persorud communication, Jan. 18, Iw.

ZFu~emore, ~ey ~xpcct that the v~ue of NDV technology ‘tspm off” to other applications such as aircraft and launch vehicles would compensate

for some of the cost at risk.

31f more test flights were conducted, a reliable Vehicle could demons~ate acceptable reliability with acceptable confidence and allOW these Potentiai

savings to be realized, but against this must be weighed the expense and delay of the extra tests.

dNational Research Councll, Pos[-challenger Evahatlon of Space Shuttle Risk Assessment llnd Management (Washington! DC: ‘ation~ AcademY

Press, January, 1988), app. D.

5one h~dred test fli@ts, if all successful, would provide only 39,4 ~rccnt statistic~ confidence in a $)$).5 percent lower confidence bo~d on

reliability.

-85–
86 ● Access to Space: The Future of U.S. Space Transportation Systems
Appendix A-The Sensitivity of NASP-Derived Vehicle Costs To Required Confidence and Actual Reliability ● 87

less than 40 percent confident that the reliability is less than 98 percent even though his SPD implies

the same expected value of reliability—98 percent-as does the SPD of the Confident Pessimist (the

expected value of reliability cannot be read from a graph of the SPD; it must be calculated from the

SPD). Similar readings of points on the SPDs of the Uncertain optimist and the Confident Optimist

reveal why they are so named.

The figure on the right shows portions of the posterior SPDs of the same four subjects, updated

after 9,900 successes have been observed in 10,000 tests-a success rate of 99 percent. The posterior

SPDs of the Uncertain Pessimist and the Uncertain Optimist are almost indistinguishable; influenced

by the test results in a logically consistent manner, their prior SPDs have converged, that of the

Uncertain Pessimist (who expected 98 percent reliability a priori) becoming more optimistic, and that

of the Uncertain Optimist (who expected 99.8 percent reliability a priori) becoming more pessimistic.

The SPDs of the Confident Pessimist and the Confident Optimist also became more similar but did not

fully converge; the high confidence implicit in the prior SPDs (and apparent as steep slopes in the

graphs) caused them to be influenced less by the test results.

Figure A-1—Probability That Test Vehicles Will Demonstrate Acceptable Reliability If .

Statistical Confidence IS Required

100 % f ’

60 %

40 %

20 %

I

v / / / / /

/

7’

4’

/ / / / / / /’ / /’ ‘ 94.5%

/ / / / / / / / 7

93.5%

o% I I I I I I I I I 92.5%

10 20 30 40 50 60 70 80 90

Required Confidence in 99.5% Reliability

Based on 100 Monte Carlo samples.

30URCE: Office of Technology Assessment, 1990.

‘.5%

%

/

Actua l

Reliability y

statistical confidence, or more, is required, a vehicle Figure A-2 shows how the expected present value of

would be rejected even if all flights were successful. If, the life-cycle costs of flying the missions in OTA’s

however, only 30 percent statistical confidence is re- Low-Growth mission model6 through the year 2020

quired, a 99.5-percent reliable vehicle would be accepted would depend on actual reliability and required confiwith a probability of about 80 percent. dence, if statistical confidence is required. The greater the

6u.s, cmw~~, office of T~~~l~gY ~W~~ment, hunch ~pt~~ for t~ Fu~re-..A ~uye/~ GM’&, OTA-ISC-383 (Washington, ~: U.S.

Government Printing Office, July 1988).
88 ● Access to Space: The Future of U.S. Space Transportation Systems

Figure A-2—Expected Present Value of Mixed-Fleet Life-Cycle Cost If Statistical Confidence Is

$160 B

$150 B

$140 B

$130 B

$120 B

Required and NDV Costs Are As Estimated by NASP JPO

Present Value of Life-Cycle Cost (FY89$)

/ I

/

I I I I I I I I I

92.5%

93.5%

94.5%

95.5%

6.5%

97.5%

8.5%

/

Actua l

Retiability

10 20 30 40 50 60 70 80 90

Required Confidence in 99.5% Reliability

Based on 100 Monte Carlo samples.

SOURCE: Office of Technology Assessment and National Aero-Space Plane Joint Program Office.

X-30’S reliability turns out to be, the greater the savings estimated by the NASP Joint Program Office (JPO),

can be.7 If managers require at least 10 percent statistical which are shown in table A-1. OTA also assumed:

confidence, they risk little or nothing compared to the 1. costs if NDVs were not attempted (figure 1-2) if the

X-30’S reliability turns out to be low, because there is little 2.

chance that an unreliable vehicle would be accepted, and

no NDV development costs are assumed to be incurred

before the decision on whether to proceed with NDV 3.

development. 8

Methodology

OTA calculated these estimates assuming that NDV- 4.

related costs are uniformly distributed over ranges

X-30 development costs are sunk costs.

The test program will consist of 100 test flights to orbit

and back; other (e.g., suborbital) test flights may be

conducted but will not be used to estimate reliability

on orbital flights.9

During the test program, the X-30S will not be

modified in any way, or operated in different ways,

that would make reliability differ from flight to

flight. 10

The government will decide in 2000 whether to

proceed with NDV development,ll based on whether

7’l”he actu~ reliability of o~rationat NDVS is assluned to be the same as that of the X-30S or prototype NDVS used to demonstrate reliability in the

flight test program.

S’l’hese est~ates exclude tie costs of developing the x-30 (or other prototype); if Congress decided now to forego development of an NDV! it co~d

save a few billion dollars by hatting the NASP program. See U.S. Congress, Congressional Budget Office, Reducing the Deficit. Spending and Revenue

Options (Washington, DC: U.S. Government Printing Office, 1990), pp. 68-70.

9The JPO actually plans only about 75 to 100 test flights, most of them suborbital. Data from suborbital test flights and ground tests of vehicle systems

and components could be used to estimate reliability on orbital flights, but this would require developing a component-level reliability model that

describes how component failures could cause vehicle loss and how component failure probabilities depend on details of vehicle assembly, maintenance,

and operation (e.g., on the speeds and altitudes at which the vehicle has flown).

l~ls ~mptlon simplifies an~ysis. ~ fact, tie x-30s co~d ~ m~lfied.<.g., after a fai]ure—~ an attempt [0 incre~ reliability, but “wiping

the slate clean” late in the test program might reduce confidence that the required reliability has been demonstrated.

1 lsome have suggest~ that if the x_30 is successful, NDVs might be develo@ pfivately [o ~rvice tie mwket for space tourism. For estimates Of

the demand for round trips to orbit as a function of ticket price, see DoD & NASA, National Space Transportation and Support Study 1995-20)0, Annex

B: Civil Needs Data Base, Version 1.1, vol. I—Summay Report, Mar. 16, 1986, pp. 3-3 1—3-32, and Gordon R. Woodcock, “Economics on the Space

Frontier: Can We Afford It?,” SS[ Update (Princeton, NJ: Space Studies Institute, May/June 1987).
Appendix A—The Sensitivity of NASP-Derived Vehicle Costs To Required Confidence and Actual Reliability ● 89

Table A-l—Ranges of Costs Estimated by NASP Joint Program Office (index year not specified)

Best Case Nominal Worst Case

Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $3,000 Ma

$4,000 M $6,000 M

Facilities (per NDV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $25 M $50 M $75 M

Production (first NDV) . . . . . . . . . . . . . . . . . . . . . . . . . . $700 M $800M $1,100 M

(% Iearninga

) . . . . . . . . . . . . . . . . . . . . . . . . 85 % 90 % 95 0/0

Operations (per NDV-year) . . . . . . . . . . . . . . . . . . . . . . $10 M $15 M $30 M

(per flight).. . . . . . . . . . . . . . . . . . . . . . . . . . $0.8 M $1.2 M $2.2 M

Failures (per failure) . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,500 M $2,000 M $2,500 M

a M = mji~ion

b le., the inCre~ntal “nit ~O~t of the nth NDV Will be (%/1 OF)@@ times the incremental unit cost of the first NDV, where Y’ is the percentage learning.

SOURCE: NASP Interagency Office, 1990

5.

6.

the required reliability (assumed to be 99.5 percent) is

demonstrated with a specified statistical confidence.

If the government decides not to proceed with NDV

development, the missions in the mission model will

be flown by Shuttles, Titan IVs, and Medium Launch

Vehicles. Construction of facilities required for

launching Titan IVs at the rates required (which began

earlier as a hedge) will continue.

If instead the government proceeds with NDV development,

(a)

(b)

(c)

(d)

(e)

Construction of only those Titan IV facilities

required for launching at the rates required to

complement the NDV will continue, possibly

after a delay .12

The actual reliability of operational NDVs will be

the same as that of the X-30s or prototype NDVs

used to demonstrate reliability in the flight test

Program. l3

Enough NDVs will be procured to make the

probability of losing them all to attrition no

greater than one percent, assuming a reliability of

99.5 percent.14

NDVs will fly all the reamed missions in OTA’s

“Low-Growth” mission model on a 1:1 basis

(i.e., one NDV flight substituting for one Shuttle

flight) and half of Titan missions 1:1, beginning

the year of initial operational capability, which

OTA assumes will be 2005.

[f and when all NDVs are lost to attrition, another

NDV will be procured at the same incremental

unit cost as the first NDV.15

The probability that X-30S or prototype NDVs would

demonstrate the required reliability (99.5 percent) with

the required confidence during the flight test program was

calculated for each combination of actual reliability and

required confidence considered. This probability-the

“acceptance probability ’’-was used in calculating the

life-cycle cost of the mixed fleet. Titan and Shuttle costs

depend on the number of missions Titans and Shuttles are

required to fly, which depends on whether NDVs are

accepted and used to complement Titans and supersede

Shuttles.

For the case in which they are, the costs of NDV

development, facilities, production, operation, and failures are estimated by Monte-Carlo techniques-i. e.,

random-event simulation. For each of 100 scenarios,

values for each of the uncertain costs in table A-1 were

generated pseudorandomly

16 and used to calculate the

life-cycle costs of the NDV fleet. The number of

operational failures in each year was also generated

pseudo-randomly, based on the actual reliability assumed,

and used to calculate NDV failure costs. For each value

of actual reliability y considered, the difference between the

70th percentile of NDV costs and the median value of

NDV costs was used as the “STAS cost risk’’--i.e., the

cost risk as defined in the Space Transportation Architecture Study17 —for the NDV fleet.

Sensitivity to

Greater-than-Expected NDV Costs

To gauge the sensitivity of the estimates in figure A-2

to greater-than-expected- NDV costs, OTA estimated

costs by the same procedure but assumed NDV-related

costs are uniformly distributed over the ranges in table

A-2. The lower bounds of these ranges areas estimated by

12B~ause hey may not IX n~d~ as s~n, and delaying expenditures for facilities allows them to be more heavily discounted.

130perationa.1 NDVS could be designed to differ from the X-30S or prototype NDVs--e.g., to have more engines-with the intent of making them

more reliable. If so designed, detailed reliability models (footnote 9) of both X-30S and operational NDVS would be needed to estimate operational NDV

reliability on the basis of X-30 flight tests. If operational NDVS differ significantly from X-30S, X-30 flight tests may provide little information about

NDV reliability; in any case, the updating procedure would be much more complicated than updating based solely on test flights of similar vehicles under

similar conditions.

lq~cor~ng to this criterion, the fleetsize should be eight for the Low-Growth mission model (534 NDV flights).

15Thjs j5 Optimistic; jt neg]wts ~rocurement delay and the remote psjbj]jty that one NDV may be required to fly more flights than the NASP JPO

assumes it will be able to: 250 to 500, but nominally 400.

16The costs were ~sum~ to be distributed ~iformly between the worst-case and best-case values in table A-1.

17u.s. Con=ss, Office of Technology Assessment, op. cit.. footnote G.
90 ● Access to Space: The Future of U.S. Space Transportation Systems

the NASP JPO (table A-l); the upper bounds of these

ranges are twice the upper bounds of the ranges estimated

by the NASP JPO (in the case of percentage learning, the

upper bound is twice as close to 100 percent). Figure A-3

shows the resulting cost estimates.

Cost Estimates,

If Subjective Confidence Is Allowed

OTA has also estimated savings and losses for cases in

which the government decides whether to proceed with

NDV development based on the subjective (rather than

statistical) confidence with which the required reliability

(assumed to be 99.5 percent) is demonstrated. The

confidence level is calculated by Bayesian inference. For

illustration, the estimates were calculated assuming the

prior distribution of the “Confident Optimist” of box

A-A, which implies an expected reliability of 99.8

percent-the same nominal reliability estimated by the

NASP JPO. Figure A-4 shows the proto-NDV acceptance

probabilities, and figure A-5 the life-cycle costs, estimated under these assumptions, assuming OTA’s LowGrowth mission model and NDV-related costs uniformly

distributed over ranges estimated by the NASP JPO (table

A-l).

To gauge the sensitivity of the estimates in figure A-5

to greater-than-expected NDV costs, OTA estimated

costs by the same procedure but assumed that NDVrelated costs are uniformly distributed over the ranges in

table A-2. Figure A-6 shows the life-cycle costs estimated

under these assumptions.

Figure A-5 shows that if NDV costs areas estimated by

the NASP JPO, there is little risk that an unacceptably

Table A-2—Ranges of Costs Assumed by OTA

for Sensitivity Analysis

Best Case Worst Case

Development . . . . . . . . . . . . . . . . . . . . $3,000 Ma $12,000 M

Facilities (per NDV) . . . . . . . . . . . . . . $150 M

Production (first NDV) . . . . . . . . . . . . $700 M $2,200 M

(% learning) . . . . . . . . . . . 857. 97.570

Operations (per NDV-year) . . . . . . . . $10 M $60 M

(per flight) . . . . . . . . . . . . $0.8 M $4.4 M

Failures (per failure). . . . . . . . . . . . . . $1,500 M $5,000 M

aM = rmllion.

SOURCE: Office of Technology Assessment, 1990.

unreliable vehicle would be accepted and, as a consequence, the mixed-fleet life-cycle cost (figure A-5) would

exceed that of the current mixed fleet (the Titan-IV option

in figure 1-2).

However, if NDV costs can range up to twice the upper

bounds estimated by the NASP JPO, figure A-6 shows

that there could be a significant risk of loss caused by

accepting an unacceptably unreliable vehicle. For example, if only 10 percent confidence is required and actual

reliability turns out to be 92.5 percent, the median

life-cycle cost would be about $16 billion more than if the

NDV were rejected, or not attempted, because the failures

that would occur in the test flight program would probably

not reduce the confidence in NDV reliability (over 98.9

percent, a priori) below 10 percent. If 90 percent

confidence were required (see figure A-6), or 10 percent

statistical confidence were required (see figure A-3), or

prior confidence in NDV reliability were lower, this risk

could be made negligible, but this would also reduce the

probability of accepting, and benefiting from, a reliable

NDV,
Appendix A—The Sensitivity of NASP-Derived Vehicle Costs To Required Confidence and Actual Reliability ● 91

Figure A-3-Expected Present Value of Mixed-Fleet Life-Cycle Cost If Statistical Confidence Is Required and NDV Costs May Be 2X NASP JPO Estimates

Present Value of Life-Cycle Cost (FY89$)

$160

$150

$140

$130

$120

B

B

B .5%

%

B

/

Actual

B Reliability

10 20 30 40 50 60 70 80 90

Required Confidence in 99.5% Reliability

Based on 100 Monte Carlo samples.

Figure A-4--Probability That Test Vehicles Will Demonstrate Acceptable Reliability If Subjective Confidence Is Allowed

Probability of Accepting Vehicle

/ /’

100

8 0

60

4 0

20

0

%

%

10 20 30 40 50 60 70 80 90

Required Confidence in 99.5% Reliability

Based on 100 Monte Carlo samples.

‘.5%

%

/

Actual

Reliability y

SOURCE: of Assessment and National Plane Joint Program Office, 1990.
92 ● Access to Space: The Future of U.S. Space Transportation Systems

Figure A-5-Expected Present Value of Mixed-Fleet Life-Cycle Cost If Subjective Confidence Is

Allowed and NDV Costs Are As Estimated by NASP JPO

Present Value of Life-Cycle Cost (FY89$)

$160 B 1

$150 B

$140 B

I

$130 B

$120 B

Based on 100

I IIIII

10 20 30 40 50 60 70 80 90

Required Confidence in 99.5% Reliability

Monte Carlo samples.

..5%

%

.5%

%

/

Actual

Reliability y

Figure A-6--Expected Present Value of Mixed-Fleet Life-Cycle Cost If Subjective Confidence Is

Allowed and NDV Costs May Be 2X NASP JPO Estimates

Present Value of Life-Cycle Cost (FY89$)

$160 B

$150 B

$140 B 

$130 B

$120 B 

Based on 100

‘.5%

%

/

Actual

Reliabilitv

10 20 30 40 50 60 70 80 90 .

Required Confidence in 99.5% Reliability

Monte Carlo samples.

SOURCE: Office of Assessment and National Plane Joint Program Office, 1990.