r ,A* 

NASA Technical Memorandum 102298 

AIAA-89-2298 

NASA's Chemical Transfer Propulsion 

Program for Pathfinder 

Ned P. Hannum and Frank D. Berkopec 

NASA Lewis Research Center 

Cleveland, Ohio 

Robert L. Zurawski 

NASA Headquarters 

Washington, D. C. 

Prepared for the 

25th Joint Propulsion Conference 

cosponsored by the AIAA, ASME, SAE, and ASEE 

Monterey , California, July 10- 12, 1989 

(NASA-TH-102298) bi4SA'S CHEMICAL TBBISF'ER ti8 9-268 76 

Lewis Research Center) 18 p CSCL 228 

P3OPULSION PROGRbR FOE PATEFINDER {BIrSA, 

Unclas 

63/15 0224222 
NASA's Chemical Transfer Propulsion Program for Pathfinder 

Ned P. Hannum and Frank D. Berkopec 

NASA Lewis Research Center 

Cleveland, Ohio 44135 

Robert L. Zurawski 

NASA Headquarters 

Washington, D.C. 20546 

ABSTRACT 

Pathfinder is a research and technology project, with specific 

deliverables, initiated by the National Aeronautics and Space Administration 

(NASA) which will strengthen the technology base of the United States civil 

space program in preparation for future space exploration missions. 

Pathfinder begins in Fiscal Year 1989, and is to advance a collection of 

critical technologies for these missions and ensure technology readiness for 

future national decisions regarding exploration of the solar system. 

The four major thrusts of Pathfinder are: Surface Exploration, In-Space 

Operations, Humans-in-Space, and Space Transfer. The Space Transfer thrust 

will provide the critical technologies needed for transportation to, and 

return from, the Moon, Mars, and other planets in the Solar System, as well as 

for reliable and cost-effective Earth-orbit operations. A key element of this 

thrust is the Chemical Transfer Propulsion program which will provide the 

propulsion technology for high performance, liquid oxygen/liquid hydrogen 

expander cycle engines which may be operated and maintained in space. These 

advanced engines will enhance or enable a variety of future space exploration 

missions. 

This paper describes the program overview including the goals and 

objectives, management, technical plan, and technology transfer for the 

Chemical Transfer Propulsion element of Pathfinder. 

INTRODUCTION 

PROJECT PATHFINDER OVERVIEW 

American leadership on the space frontier requires aggressive programs in 

technology development. Technological advance will be critical to programs 

for future space exploration missions (Ref. 1). These missions may include an 

intensive study of the Earth, a return to the Moon, piloted missions to Mars, 

and the continuing robotic exploration of the Solar System (Ref. 2). The 

technologies needed for success in these ventures are many and varied. The 

National Aeronautics and Space Administration (NASA), recognizing that it must 

intensify and broaden the scope of its research and technology program to 

provide the range of technical options and evaluate technological readiness in 

select areas to enable future space exploration missions, is initiating 

Project Pathfinder. 

1 
Project Pathfinder is a research and technology initiative which will 

strengthen the technology base of the United States civil space program in 

preparation for future space exploration missions. Pathfinder is a long-term 

program of both research and demonstrations which begins in Fiscal Year 1989. 

It io managed by the NASA Office of Aeronautics and Space Technology (OAST) 

and has the goals to advance a collection of critical technologies for future 

space missions and to ensure technology readiness for future national 

datlsions regarding exploration of the Solar System (Ref. 3). 

Pathfinder is organized into four programtic thrusts: 1) Surface 

Exploration, 2) In-Space Operations, 3) Humans-in-Space, and 4) Space 

Transfer, as shown in Figure 1. The Surface Exploration thrust will provide 

the critical technologies needed for gathering scientific and engineering 

data for robotic and piloted missions to the Moon, Mars and other planets in 

the Solar System. Technologies needed for Earth-orbit staging and 

operations, as well as planetary operations, will be provided in the In-Space 

Operations thrust. The Humans-in-Space Thrust will provide technology and 

understanding needed to ensure safe and productive human space exploration 

missions. Finally, the Space Transfer thrust will provide critical 

technology for transportation to, and return from, the Moon, Mars, and other 

planets in the Solar System, as well as for reliable and cost-effective 

Earth-orbit operations (Ref 4). 

Chemical Transfer Propulsion is a key element of the Space Transfer 

thrust and will provide the technology for high-performance, liquid 

oxygedliquid hydrogen expander cycle engines for space-based transfer 

vehicles, as well as for Lunar and Mars landers. 

CHEMICAL TRANSFER PROPULSION PROGRAM OVERVIEW 

MISSION STUDIES AND TECHNOLOGY REQUIREMENTS 

In its report to NASA in 1987, the Committee on Advanced Space Technology 

of the National Research Council recommended that advanced propulsion 

technologies for future space missions be afforded the highest priority of 

RLD activity within NASA. Recognizing that propulsion is a pacing item for 

future space exploration missions, the committee suggested that NASA pursue a 

strong program leading to the design and development of reusable cryogenic 

and longevity (Ref. 5). The NASA Office of Aeronautics and Space Technology 

has responded with the Chemical Transfer Propulsion element of Pathfinder, 

which will provide the technology necessary to confidently proceed with the 

development of high performance liquid oxygen/liqufd hydrogen expander cycle 

engines for future space exploration missions, as well as to fulfill the 

orbit transfer role in Earth space. 

I transfer vehicle engines with features of fault tolerance, high reliability 

NASA's planning for future exploration of the solar system includes 

unmanned (precursor) and manned missions to Mars and its moons, as well as a 

resumption of manned missions to the Moon to establish Lunar observatories. 

A portion of the cost for these missions depends on launch vehicle and 

on-orbit fuel requirements. One of the keys to reducing cost is to minimize 

the propellant mass in low-Earth orbit required to achieve a transfer 

trajectory, to accomplish orbit insertion, to effect a planetary landing, and 

2 
to return to Earth. Launch of the many millions of pounds required for 

virtually all future space exploration mission scenarios may be affordable 

only if advanced propulsion systems can be made available (Ref. 5). Reduced 

propellant requirements in orbit translate to substantial cost savings 

because fewer Earth-to-orbit vehicle launches are required to accomplish the 

mlssion. For example, in the case of a manned Mars mission, an increase of 

35 seconds of engine specific impulse saves the cost of at least two 

Earth-to-orbit vehicle launches. 

fn-orbit propellant mass requirements is the development of high-performance 

chemical transfer engines. 

A key enabling technology to greatly reduce 

Another key to reduced cost is to develop reusable transfer stages that 

are based in and operated from low-Earth orbit, are operated in low-Earth 

orbit (LEO) to geosynchronous orbit (GEO) space, and are used in the 

exploration missions. Technologies that will enable automated in-orbit 

operation (such as refueling, maintenance, servicing, and preflight systems 

checkout, as well as fault-tolerant in-flight operation) are critical to the 

successful development and use of space-based vehicle systems. Integrated 

controls and health monitoring systems will be required for such fault 

tolerant engines which will be repeatedly operated and maintained in space. 

The NASA Office of Exploration (OEXP) is currently studying several 

mission scenarios to provide recomnendations and alternatives for an early 

1990's national decision on a focused program for human exploration of the 

Solar System. These mission scenarios include human expeditions to the 

Martian moon Phobos, human expeditions to Mars, human tended Lunar 

observatories, and an evolutionary expansion from a Lunar outpost to Mars 

exploration (Ref. 6). A preliminary set of propulsion technology 

requirements generated by OEXP for these mission scenarios is presented in 

Table I. Requirements for these propulsion systems include: 1) fault 

tolerance and high reliability, 2) space basing, long life, and space 

maintainability, 3) man rating, 4) reusability, restart capability, and 

checkout before reuse, 5) diagnostic capability (integrated controls and 

health monitoring), and 6) some level of on-orbit assembly. 

TECHNOLOGY ASSESSMENT 

The only upper stage liquid oxygen/liquid hydrogen expander cycle engine 

currently in operation is the RLlO engine which was developed and certified 

in the late 1950's and early 1960's. Two RL10A-3-3A engines are used on the 

expendable Atlas Centaur vehicle. The RL10A-3-3A is a regeneratively cooled, 

turbopump-fed rocket engine that weighs approximately 310 pounds and produces 

a rated vacuum thrust of 16,500 pounds (Ref. 7). With a chamber pressure of 

465 psia, the engine delivers moderate performance (444.4 seconds specific 

impulse at mixture ratio of 5:l using a 61:l area ratio nozzle), has limited 

throttling capability (with significant performance penalties) and no 

on-board diagnostics. 

vehicles. 

It was designed for and is only used on expendable 

In the early 1970's. NASA initiated a technology program directed toward 

an advanced liquid oxygen/liquid hydrogen upper stage engine, as shown in 

Figure 2. 

utilizing a staged combustion cycle for very high pressure, high performance 

The program initially focused on an advanced space engine 

3 
operation. The Advanced Space Engine technology program was carried through 

component verification testing, at which time it was decided that a liquid 

oxygen/liquid hydrogen expander cycle engine would better satisfy future 

mission requirements. The Orbital Transfer Rocket Engine technology program, 

which began in the early 198O's, focused on advanced component technologies 

for high performance (high pressure), reusable liquid oxygen/liquid hydrogen 

expander cycle engines which would be space based and man-rated. 

were focused on technologies for high-speed turbomachinery, 

hlgh-heat-transfer combustors, large-area-ratio nozzles, and health 

monitoring systems. The basic proof-of-concept of advanced, high-performance 

liquid oxygen/liquid hydrogen e x p a n d e r c y c l e c o m p o n e n t s w a s only partially 

demonstrated during this program, which has given way to the Chemical 

Transfer Propulsion Program. Some limited testing of turbomachinery and 

health monitoring components (sensors) in a breadboard e n g i n e w a s also 

conducted. 

Efforts 

What remains to be accomplished in order to confidently proceed with the 

development of an advanced high performance liquid oxygen/liquid hydrogen 

expander cycle engine for future space exploration missions is: 1) the 

validation testing of engine components, 2) integration and testing of 

components assembled into an engine system (to study component interactions, 

system transients, system dynamics, and health monitoring/control systems), 

and 3) the verification of design and a n a l y s i s m e t h o d o l o g i e s a t both the 

engine component and engine system level. Pathfinder Chemical Transfer 

Propulsion is a focused program intended to elevate technology readiness (to 

Level 6 as shown in Table 11) by bridging the t e c h n o l o g y g a p between basic 

research and technology efforts conducted to date (Level 3) and the eventual 

development of advanced liquid oxygen/liquid hydrogen engines for space 

transfer vehicles. 

CHEMICAL TRANSFER PROPULSION PROGRAM GOALS AND OBJECTIVES 

The goal of the Chemical Transfer Propulsion Program is to provide the 

technology necessary to confidently proceed, in the 1990's. with the 

development of high-performance, liquid oxygen/liquid hydrogen expander cycle 

engines for future space exploration missions. Major program objectives are: 

(1) Proof-of-concept demonstration of a high performance, liquid 

oxygen/liquid hydrogen expander cycle in a test bed engine system, 

including: 

(a) Validation of high pressure, high performance expander cycles 

(b) InvestigatZon of engine system icteractions, transients, 

dynamics, control functions, and health monitoring techniques 

(2) The validation of a design and a n a l y s i s m e t h o d o l o g i e s to support the 

development of future, high performance liquid oxygen/liquid 

hydrogen expander cycle engines including; 

(a) Assembly and validation of analytical methodologies f o r t h e 

design of advanced liquid oxygen/liquid hydrogen expander cycle 

engine components and systems 
i 

(b) Validation of design concepts for high performance, 

space-based, throttleable liquid oxygen/liquid hydrogen 

expander cycle engines 

(3) Mission-focused components integrated into a focused-technology test 

bed engine to demonstrate the high performance, liquid oxygen/liquid 

hydrogen expander cycle engine system technology that is to be the 

basis for future space engine development 

(4) Results of propulsion studies conducted to define firm propulsion 

requirements and to trade propulsion system performance, 

configuration, operating characteristics, and the attributes that are 

key to long-term space transportation infrastructures (space-basing, 

reuse, man-ratlng, fault tolerance) 

TECHNICAL APPROACH 

At the present time, future space exploration mission scenarios have not 

been defined to a point where firm propulsion requirements exist. However, 

technology goals for an advanced liquid oxygen/liquid hydrogen space engine 

which support the range of future mission options are presented in Table 111. 

The major technical issues for an advanced liquid oxygen/liquid hydrogen 

expander cycle engine which will be addressed in the Chemical Transfer 

Propul si on Program are : 

(1) High performance: 

High performance engine operation (Goal of 490 lbf-sec/lbm vacuum 

specific impulse) 

(2) Deep throttling: 

Continuous and stable engine operation from rated thrust to perhaps 

5% (20:l vacuum thrust throttling ratio) with minimum performance loss 

(3) Reusability: 

Specifications of the number of starts and the number of hours of 

operational life, as well as the number of starts and hours of 

service-free life are to be established; preliminary assessments 

are: 500 starts/20 hours operational life, 100 starts/4 hours 

service free life 

(4) Space Basing: 

Modular engine design for space maintenance, operating 

characteristics and diagnostics and techniques that facilitate 

long-term storage and operations in space 

(5) Fault tolerance: 

Fault tolerance in the "classical" sense: the propulsion system 

shall tolerate a given number of failures without causing a hazard, 

5 
or fail operational/fail safe (as an additional requirement, the 

system shall tolerate off-design operation of some combinations of 

components in a way that maintains system durability to allow 

completion of the mission) 

(6) Man rating 

High reliability; redundancy of all critical systems; design and 

operational safety; proven design standards; enable safe haven or 

return 

The technical approach to be used in the Chemical Transfer Propulsion 

Program is summarized in Figure 3. The program consists of propulsion 

studies, focused advanced component technology efforts, and systems technology 

activities. Drawing on technology developed in the Orbital Transfer Rocket 

Engine Technology program, advanced liquid oxygen/liquid hydrogen expander 

cycle engine components will be designed, fabricated and tested in component 

test stands. The components will then be assembled into a test bed engine for 

systems testing. In parallel with these activities, propulsion studies will 

be conducted to define propulsion system requirements which will guide the 

selection of .focused advanced component technologies to be pursued in the 

program. The focused advanced engine components emerging from these efforts 

will be integrated into a focused-technology test bed engine. This engine 

system will be tested to complete Level 6 of technology readiness. 

MANAGEMENT PLAN 

OVERVIEW 

The Chemical Transfer Propulsion Program is a focused technology program 

leading to technology demonstrations of an advanced liquid oxygen/liquid 

hydrogen expander cycle engine system and engine components. The extensive 

variety of work being performed in the program requires a management approach 

which is tailored to coordinating and integrating the various work 

activities. The management system must ensure achievement of planned 

accomplishments, effective reporting and control, and permit prompt replanning 

if required. The work breakdown structure, management structure, program 

coordination, planning and documentation, reporting, and advisory groups for 

the Chemical Transfer Propulsion program are described in this section. 

WORK BREAKDOWN STRUCTURE 

The Chemical Transfer Propulsion program is divided into three major 

research areas which allows work to be focused in critical areas and provides 

a flow mechanism for raising the technology to higher levels of hardware 

definition, leading to the eventual testing of an advanced liquid 

oxygen/liquid hydrogen expander cycle focused-technology test bed engine in 

the late 1990's. The major work packages are; (1) Propulsion Studies (2) 

Mission-Focused Technologies and (3) Engine Systems Technologies. Figure 4 

illustrates the top-level work breakdown structure elements. The work flows 

from one element to the succeeding one. The propulsion studies will generate 

propulsion requirements to guide the selection of mission-focused 

technologies. Advanced engine subcomponents and components emerging from the 

6 
mission-focused technology efforts will be tested in an engine system in the 

focused-technology test bed. 

ORGANIZATION AND MANAGEMENT STRUCTURE 

Program management responsibilities for the Chemical Transfer Propulsion 

Program will reside in OAST's Propulsion, Power and Energy Division. A 

Program Manager will establish overall programtic goals and objectives and 

serve as the focal point at NASA Headquarters for the Chemical Transfer 

Propulsion Program. The Chemical Transfer Propulsion Program Manager will 

report on regular basis to the Program Manager for Pathfinder as to the 

status, problems and accomplishments of the program. 

The NASA Lewis Research Center (LeRC) will be the lead center for the 

Chemical Transfer Propulsion Program. As the lead center, LeRC will assume 

full responsibility of achieving the goals and objectives of the program, as 

well as for integrating next-tier assignments in the program both within LeRC 

and at participating Centers. 

The Lewis Research Center will plan and integrate Chemical Transfer 

Propulsion activities and execute some portion of that plan within the 

Center. A Project Manager located at LeRC will be the focal point of all 

field installation activity bearing directly on the Chemical Transfer 

Propulsion Program and will be exclusively responsible for the execution of 

the program. In essence, the Project Manager will be responsible for the 

day-to-day supervision and the execution of the program as carried out by 

industrial contractors, field installation personnel, and university 

participants. These responsibilities include: 1) technical planning, 2) 

maintaining and reporting schedules, 3) planning, disbursement and tracking of 

resources, and 4) facility planning as required. 

The Chemical Transfer Propulsion Management Structure is depicted in 

Figure 5. 

PROGRAM COORDINATION 

The LeRC Project Manager will be kept informed and will coordinate 

information with the Office of Exploration (OEXP), and the Office of Space 

Flight (OSF), to assure that future space vehicle requirements guide 

propulsion technology efforts within the Chemical Transfer Propulsion 

program. OEXP will define scenarios for future, human exploration missions in 

the Solar System. OSF will establish space vehicle requirements for these 

future space exploration missions, which will guide the development of 

propulsion technologies. Mission and vehicle definition will be important in 

determining propulsion system characteristics such as; (1) minimum performance 

requirements, (2) thrust level, (3) throttling requirements, (4) life, 

reliability and reusability requirements and (5) design criteria for in-space 

engine operation and maintenance. 

Within OAST, coordination will be maintained with the propulsion R&T Base 

program, as applicable to chemical transfer propulsion technologies. External 

to OAST, coordination will also be maintained with the Department of Defense 

through the Joint Army, Navy, NASA, Air Force (JANNAF) Interagency Propulsion 

7 
Committee and the NASA/AF Space Technology Interdependency Group (STIG) for 

the exchange of information and technology where propulsion technologies and 

application are common. 

PROGRAM REVIEWS 

Formal reviews of the Chemical Transfer Propulsion Program will be 

canducted semi-annually; mid-way during, and near the end of, each fiscal 

year. The focus of the mid-fiscal year review will be on program content, 

status and progress versus the Project Plan. Test results, experimental and 

analytical data, and program accomplishments will be central to this review. 

The review will include an advisory cornittee f o r t h e Chemical Transfer 

Propulsion program and principal managers and technical specialists directly 

involved in the program from Headquarters (Program Manager), the lead center 

(Project Manager), participating centers, contractors and universities. 

The purpose of the review near the end of the fiscal year will be to 

evaluate the specific Project Plan against schedule, accomplishments and 

resources. During this formal review, each participating center will 

represent its area of expertise and responsibility. The lead center will be 

responsible for making an integrated assessment of progress and 

accomplishments versus the Project Plan. Special, detailed technical reviews 

will also be conducted as necessary to ensure a planned pace of accomplishment 

to meet the goals and objectives of the program and to expose any problems or 

potential malfunctions before committing the program to the next step. These 

special reviews will include: 

(1) Review of design and analysis methodologies for liquid oxygen/liquid 

hydrogen expander cycle engine components/systems 

(2) Preliminary and critical design reviews f o r t h e test bed engine 

(3) Propulsion system trade studies 

(4) Technology reviews for advanced (mission-focused) engine components 

(prior to their integration into the focused-technology test bed) 

(5) Engine systems technology review ( p r i o r t o integration of the test 

bed engine system into the focused-technology test bed) 

Additionally, there will be special technical reviews scheduled and 

implemented by the LeRC Project Manager. 

ADVISORY COMMITTEES 

The OAST Space Systems Technology Advisory Committee (SSTAC) and the 

Aerospace Research and Technology Subcommittee (ARTS) will be utilized f o r t h e 

Chemical Transfer Propulsion program. These advisory groups will provide 

top-level programmatic and technical guidance to the program. In addition, a 

Space Propulsion Advisory Committee will provide a more specific advisory 

function to the Chemical Transfer Propulsion Program. This committee composed 

8 
of principal managers and technical specialists from NASA, other government 

agencies, industry and academe and will provide specific programmatic and 

technical guidance to the program once each year at the mid-fiscal year 

revtw. 

TECHNICAL PLAN 

TECHNICAL OVE RV I EW 

The Chemical Transfer Propulsion program will evolve fundamental liquid 

oxygen/liquid hydrogen expander cycle propulsion technologies through 

component, subsystem and system hardware demonstrations. Work in the Base R&T 

program over the past several years has been directed towards establishing 

engine design concepts capable of meeting expected mission requirements and 

pursuing critical technology advances necessary to achieve performance, life, 

and operational goals. Advanced design concepts and analytical methods have 

also been developed using laboratory and specially designed test equipment. 

The Chemical Transfer Propulsion program will build on the R&T Base by 

moving progressively through full-scale component, subsystem, and system level 

validations and demonstrations. Propulsion studies, mission focused 

technology efforts, and engine system technology efforts will be conducted, 

leading to the testing of a high performance liquid oxygen/liquid hydrogen 

expander cycle engine with mission focus. The objectives and overall 

technical approach for each of these three elements are described in the 

following sections. 

TECHNOLOGY READINESS OBJECTIVES 

The technology readiness level of the liquid oxygen/liquid hydrogen 

expander cycle engine, as the Chemical Transfer Propulsion program is 

initiated in Fiscal Year 1989, can be considered Level 3, as shown in Table 

11. Key components and related component analytical models for high 

performance liquid oxygen/liquid hydrogen expander cycle engines, such as 

pumps, turbines, thrust chambers and health monitoring devices, have been 

designed, fabricated and tested for proof-of-concept in the Base R&T program 

over the past several years. With this as a starting point, the Chemical 

Transfer Propulsion program will design, fabricate, and test components based 

on these proof-of-concept designs. These components will be tested in 

component test stands to determine expected performance and validate analysis 

and design methodologies. 

When the technology readiness is be elevated to Level 4, the components 

will be integrated into a test bed engine for system characterization 

testing. Advanced engine components emerging from the Mission-Focused 

Technology element will be integrated with the test bed engine to form a 

focused-technology test bed and elevate technology readiness to Level 5. 

System validation of hardware and analysis concepts will be conducted in the 

focused-technology test bed in a simulated space environment to complete Level 

6 of technology readiness. At this point in the program, in the late 199O's, 

the goals and objectives of the Chemical Transfer Propulsion program will be 

,met. 

development program. 

Validated hardware and design methodologies will be available to the 

9 
PROPULSION STUDIES 

Objectives. Propulsion system studies will be conducted in the Chemical 

’Transfer Propulsion Program to provide engine parametric data to support the 

mission/vehicle studies being conducted by the OEXP and the OSF. 

will also identify and assess the technology requirements of candidate 

propulsion systems resulting from the vehicle studies. 

The studies 

Technical Approach. The initial propulsion system parametric data 

packages needed for the mission/vehicle studies will be generated as a task 

under the existing OTV (Orbit Transfer Vehicle) Rocket Engine Technology 

contracts with Aerojet Techsystems Company, Pratt 6 Whitney, and Rocketdyne. 

These data packages will be provided to the OEXP and OSF vehicle contractors. 

Provisions will be made to enable close coordination between vehicle and 

engine study contractors such that the impact of vehicle derived requirements 

on the engine system can be assessed and the results utilized in the vehicle 

trade studies. 

Once propulsion system requirements for the vehicles have been defined, 

mission-focused propulsion system studies will be conducted to optimize the 

engine components and/or systems. 

Hission-Focused Technologies activity. 

These studies will be used to guide the 

Schedule of Milestones and Deliverables. The objectives for this element 

are to support the mission/vehicle studies by OEXP and OSF and to implement 

the results of the mission vehicle studies into the Chemical Transfer 

Propulsion Program. 

Del i verabl es are : 

(1 ) Engine parametric data packages FY89 

(2) Special engine parametric data packages FY90 

.I” (3) Mission-focused engine component requirements FY92 

(4) Propulsion trade studies FY92 

HISSION-FOCUSED TECHNOLOGIES 

Objective. The objective of Mission Focused Technologies is to 

provide missi’m-specific technology for inclusion into the Focused-Technology 

Test Bed engine that is scheduled for 1994. This technology will complement 

the results of the earlier engine technology from the OTV effort. 

Wission-Focused Technologies will include those issues that have not yet been 

defined; but are size, mission, and cycle specific. These issues are not 

being covered in the early engine technology effort but will be defined as a 

result of ongoing propulsion studies. 

The 

Technical Approach. The technical approach will be to define those 

technology issues that are specific to a space-based, man-rated, reusable, 

fault-tolerant, liquid oxygen/liquid hydrogen expander-cycle engine that will 

be used for future space exploration. Definition will come from 

10 
the propulsion studies. They will be the thrust level, throttleability range, 

mixture-ratio range, and size envelope. Where these aspects can not be 

defined, a broad range of values will be pursued. Up-dating of the 

configuration and cycle candidates will also be results of the propulsion 

studies. With this narrowing of configurations, the technology issues 

specific to these configurations will be identified. 

Once identified, these technology issues will be pursued both as 

individual components, and as sub-systems in a series of proof-of-concept 

tasks (Level 3). These tasks would lead next to the component validation work 

at Level 4, and ultimately to the test bed engine demonstration work at Level 

5. 

Schedule of Milestones and Deliverables. The key milestone for this 

work package is to provide demonstrated mission focused components f o r t h e 

build-up of the focused-technology test bed engine in FY94. A supplementary 

milestone is to have all of the mission-focused components available and 

characterized by FY 97. 

In order to meet these goals, several intermediate milestones can be 

listed. One is to have proof-of-concept validated mission-focused components 

(Level 3) completed in FY 92. To accomplish this, work on the mission-focused 

components must start in FY 89. 

ENGINE SYSTEMS TECHNOLOGY 

Objectives. The objectives of this work package element are: 1) 

validation of the high pressure, high performance e x p a n d e r c y c l e concept at 

the engine system level, 2) verification of the 1989 state-of-the-art 

methodologies for design and analysis of high pressure, high performance 

expander cycle components and engine system, 3) investigation of system 

effects on component design, control functions, and health monitoring 

techniques, and 4) demonstration of advanced, mission-focused components in a 

focused-technology test bed engine. The testing of the focused-technology 

test bed engine in a simulated environment will be the demonstration of the 

chemical transfer propulsion technology base for future space exploration 

missions. 

Technical Approach. The Engine Systems Technology will consist of 

one or more contract efforts and an in-house NASA LeRC effort. 

Using the technology developed in the RbT Base in the 1980's. a 

Test bed engine design will utilize the state-of-the-art design and 

contractor or ccntractors will design, fabricate, acceptance test, and deliver 

to NASA LeRC advanced, high pressure, high performance expander cycle test bed 

engines. 

analysis methodologies available. These methodologies will be verified during 

contractor testing of engine components and during the NASA LeRC in-house test 

bed engine test program. 

The NASA LeRC in-house effort will be an extensive test program of 

the test bed engine to: 

11 
Validate the high pressure, high performance expander cycle 

concept at the engine system level 

Investigate engine system interactions, transients, and 

dynamics and what effect they have on mission-focused 

component designs 

Investigate engine control functions and health monitoring 

techniques to help direct the mission-focused technology 

efforts 

Verify engine system design and analysis methodologies 

As advanced components emerge from the Mission-Focused Technologies 

efforts they will be integrated into the test bed engine for system level 

testing. In this manner, the 1989-technology test bed engine will evolve into 

l a focused-technology test bed engine in the 1994-1996 time period. 

I TECHNOLOGY TRANSFER PLAN 

~ 

The effective transfer of propulsion technologies from the research 

center to the development center where the technology will eventually be 

developed into operational systems for future space transfer missions is 

recognized as a major goal of the Chemical Transfer Propulsion Program. 

Planning for the transition of Chemical Transfer Propulsion technology to 

advanced development in preparation for implementation involves both 

Headquarters and the field centers. 

REFERENCES 

1. Pioneering the Space Frontier. The Report of the National 

Commission on Space; Bantum Books, 1986. 

2. Ride. S.K.: Leadership and America's Future in Space. NASA 

TM-89638, 1987. 

3. Project Pathfinder: Technology Benefits Assessment. Office of 

Aeronautics and Space Technology, NASA, Nov. 1987. 

I 4. Project Pathfinder: Research and Technology to Enable Future Space 

Missions. Office of Aeronautics and Space Technology, NASA, 

Brochure/JPL 400-330, Dec. 1987. 

5. Space Technology to Meet Future Needs. National Research Council. 

National Academy Press. Washington, D.C. 1987. (NASA CR-181473.) 

6. Prerequisite Requirements for Exploration Class Missions. Version 

2.1, NASA Office of Exploration Document No. Z-MAS-PRD-003. May 

1988. 

I 7. RL-10 Liquid Rocket Engine Service Manual: Model RL10-10A-3-3A. 

United Technologies, Pratt & Whitney Aircraft Group, Feb. 15, 1982. 

12 
I '- 

75-100 K 

20-40 K 

20-40 K 

20-40 K 

(I 

LOXlLH2 > 460 

LOXILH2 s 480 

LOXlLH2 460 

Noto 1 Max 

MISSION 

Msrs Transtor 

(1st i 2nd st-) 

Lunsr Trsnsfor 

Mars transfor 

(3rd stsgo) 

YIrULunar Roturn 

YIlrmdYoon 

Dortont 

1 

yur.ndyoon 

Ascont 

I I 

BURN 

TIME 

e 30 min 

45-90 

mln 

10-20 

mln 

20 rnln 

REUSE 

YOS 

(10) 

YOS 

(10) 

Mars-No 

Noon-Yos 

Msrs-No 

Noon-Yo# 

(10) 

MROTNE ABLl 

No 

No 

Yes 

wo 

SPACE 

~(POSURI 

Months 

Yesrs 

Yesrr 

roars 

Noto 1: Yurt bo tornprtlbk wlth surf- hut loads and stmy tinm to 

nduco propllsnt lossos to rnlsslon accoptsblo kvols 

Table I: Chemical Transfer Propulsion Technology Requlremcnts 

FEASIBILITY 

BASK: PRlNCIPLES OBSERVED & REPORTED 

TECHNOLOGY CONCEPWAPPLICATION 

FORMULATED 

Y- 

\- 

ANALYTICAL AND EXPERIMENTAL CRITICAL 

FUNCTION ANDlOR CHARACTERISTIC 

PROOF-OF-CONCEPT 

COMPONENT AND/OR BREADBOARD 

VALIDATION IN LABORATORY 

COMPONENT ANDlOR BREADBOARD 

DEMONSTRATION IN RELEVENT 

ENVIRONMENT 

SYSTEM VALIDATION MODEL DEMONSTRATED 

IN SIMULATED ENVIRONMENT 

SYSTEM VALIDATION MODEL DEMONSTRATED 

IN SPACE 

Table II: Technology Readlness Levels 

13 
I. 

Roteronce Spaw Transtor 

Englno Syslom Vohlck Englm 

Paramoler (RL-1 OA-3-3A) lochnology Ooals 

nwog.n 

~V0.n 

no( S~~Id 

Expondor 

16,500 Ibf' 

444.4 lbf-rocllbm 

5.0. 

4.4 IO 5.6 

465 pslr' 

61 :l 

aio iba 

70.1 In. 

3 dmr. &oo uc. 

Errlh 

m 

wW0l )cnM.d 

worr 

(kr* 

PROJECT 

PATHFINDER 

I 1 7 

MISSION I 1 

STUDIES 

SURFACE 

EXPLORATION OPERATIONS TRANSFER 

Figure 1 : Project Pathfinder Work Breakdown Structure 

14 
LOXIHYDROGEN SPACE 

ENGINE PROGRAMS 

RLlO 

RLlO PRODUCT 

IYPROV€YENT 

ADVANCED SPACE ENGINE 

ORBIT TRANSFER ROCKET 

ENGINE TECHNOLOGY 

AS-44 

PATHFINDER CHEMICAL 

TRANSFER PROPULSION 

Figure 2: LOXlHydrogen Upper Stage Engine History 

COMPONENT 

PROPULSION 

STUDIES 

EFFORTS 

FOCUSED 

TECHNOLOGY 

L 

TECHNOLOGY 

BREADBOARD 

ENGINE 

BASE) ORBITAL TRANSFER ROCKET ENGINE I 

R&T TECHNOLOGY 

~ 

Figure 3: Chemical Transfer Propulsion Technical Approach 

15 
Focurod Sy8tomr 

Tochnolo Studios 

I I I-’ Mirrion- II Enoine 1 

I II Studibw Tochnologior I I 

Figure 4: Work Bnrkdown Structuro for Chomicrl 

Trrnrkr Propulsion Program 

PAIHFIWDER I -RAY OAS1 I 

SPACE SVSTEMS CHEMICAL TRANSFER 

ADVISORV PROORAM MANAGER 

PROPULSION 

OAST - CODE RP COMMITTEE 

I 

ADV. STUDIES/ 

DEVELOPMENT 

LEAD CENTER FOR 

PROJECT YANAGEMENT 

LEw13 RESEARCH 

CENTER 

1 

LEWIS 

RESEARCt1 I CENTER I YARSHALL 

SPACE FLIGMT 

KEY 

-@ Adrlromnt 

+ Roqulromontr 

- cmhf Robs/ 

Fundlng 

- Plorning L 

Roporllng 

- Coordlnrllon 

Figure 5: Chemical Transfer Propulsion Management Structure 

16 
rn 

National Aeronautics and 

19. Security Classif. (of this report) 

Unclassified 

%ace Administration 

20. Security Classif. (of this page) 21. No of pages 22. Price' 

Unclassified 17 A03 

Report Documentation Page 

2. Government Accession No. NASA TM- 102298 1. Report No. 

AIAA-89-2298 

4. Title and Subtitle 

NASA's Chemical Transfer Propulsion Program for Pathfinder 

7. Author(s) 

Ned P. Hannum, Frank D. Berkopec, and Robert L. Zurawski 

9. Performing Organization Name and Address 

National Aeronautics and Space Administration 

Lewis Research Center 

Cleveland, Ohio 44135-3191 

2. Sponsoring Agency Name and Address 

National Aeronautics and Space Administration 

Washington, D.C. 20546-0001 

3. Recipient's Catalog No. 

5. Report Date 

6. Performing Organization Code 

8. Performing Organization Report No. 

E-4976 

IO. Work Unit No. 

591-41-21 

11. Contract or Grant No. 

13. Type of Report and Period Covered 

Technical Memorandum 

14. Sponsoring Agency Code 

15. Supplementary Notes 

Prepared for the 25th Joint Propulsion Conference cosponsored by the AIAA, ASME, SAE, and ASEE, 

Monterey, California, July 10-12, 1989. Ned P. Hannum and Frank D. Berkopec, NASA Lewis Research Center; 

Robert L. Zurawski, NASA Headquarters, Washington, D.C. 20546. 

16. Abstract 

Pathfinder is a research and technology project, with specific deliverables, initiated by the National Aeronautics 

and Space Administration (NASA) which will strengthen the technology base of the United States civil space 

program in preparation for future space exploration missions. Pathfinder begins in Fiscal Year 1989, and is to 

advance a collection of critical technologies for these missions and ensure technology readiness for future national 

decisions regarding exploration of the solar system. The four major thrusts of Pathfinder are: Surface Exploration, 

In-Space Operations, Humans-in-Space, and Space Transfer. The Space Transfer thrust will provide the critical 

technologies needed for transportation to, and return from, the Moon, Mars, and other planets in the Solar 

System, as well as for reliable and cost-effective Earth-orbit operations. A key element of this thrust is the 

Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid 

oxygenlliquid hydrogen expander cycle engines which may be operated and maintained in space. These advanced 

engines will enhance or enable a variety of future space exploration missions. This paper describes the program 

overview including the goals and objectives, management, technical plan, and technology transfer for the 

Chemical Transfer Propulsion element of Pathfinder. 

17. Key Words (Suggested by Author@)) 

Rockets 

Pathfinder 

Propulsion for orbit transfer 

18. Distribution Statement 

Unclassified - Unlimited 

Subject Category 15 

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