AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

AssociAte AdministrAtor

for commerciAl spAce trAnsportAtion

reseArch And development Accomplishments

fY 2004 

Associate Administrator for 

Commercial Space Transportation 

october 2004 

Destination FAA Destination FAA 032504.indd 

AST FY 2004 R&D Accomplishments 
NOTICE

Use of trade names, services, or images associated with corporate 

entities in this document does not constitute official endorsement 

of such products, services, or corporate entities, either expressed or 

implied, by the Federal Aviation Administration. 

Available from 

Federal Aviation Administration

Associate Administrator for Commercial Space Transportation

800 Independence Avenue, S.W., Rm. 331

Washington, D.C. 20591

Photo credits for front cover: 

Upper left corner image, courtesy of NASA. Upper right corner image, courtesy of 

NASA. Center left image, courtesy of Scaled Composites, LLC. (Mojave, California). 

Lower left corner image, courtesy of International Launch Services (McLean, Virginia). 

Lower right corner image, courtesy of NASA. 

Photo credits for page i: The Boeing Company, Chicago, Illinois.

All other Images created or purchased by Futron Corporation (Bethesda, Maryland).

All rights reserved.
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Mission 

AST’s mission is to ensure 

protection of the public, property, 

and the national security and 

foreign policy interests of the 

United States during a commercial 

launch or reentry activity and 

to encourage, facilitate, and 

promote U.S. commercial space 

transportation.

AST FY 2004 R&D Accomplishments 
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Introduction 

This document describes seven Research and Development	

(R&D) projects undertaken by the Associate Administrator for	

Commercial Space Transportation (AST) in the Federal Aviation	

Administration (FAA) during fiscal year 2004. Four new research	

projects were selected and assigned to anAST division. Work also	

continued on three projects initiated in FY 2003. In addition to	

a description of each project, a summary of accomplishments to	

date is provided.

The AST safety research supports the development of the	

policy,	 standards,	 and	guidance	material	needed	to	meet	FAA

goals and objectives. Such research is also essential in developing	

the knowledge necessary to maintain and improve FAA/AST	

materials used to verify that the products and procedures	

of launch vehicle and site operator licensees and applicants	

adequately comply with applicable safety standards.

To that end,AST formulated and instituted an R&D activity to	

support its mission and the FAA’s strategic goal of safety. TheAST	

Research and Development Plan provides a process for effectively	

applying resources forresearch based on clearly identified safety	

priorities each fiscal year. This Plan was used to solicit candidate	

research projects from internal sources, such as AST aerospace	

engineers and projects. External sources, such as the Commercial	

Space TransportationAdvisory Committee (COMSTAC) Reusable	

Launch Vehicle (RLV) Working Group, were also solicited.	

First,	 the	 AST	 R&D	 Advisory	 Board	 evaluated	 candidate	

research	 projects	 for	 relevance	 to	 AST’s	 mission,	 relative	

importance,	 and	 cost.	 Second,	 the	AST	 R&D	Advisory	 Board	

ranked the candidate research projects to arrive at a prioritized	

list to present	to	the AST	R&D	Senior Steering	Committee for	

review. Third, the AST R&D Senior Steering Committee selected	

the R&D projects to undertake in FY 2004 that had the greatest	

potential	 to	 fulfill	 AST’s	 mission	 and	 to	 meet	 its	 budgeted	

requirements.	 Lastly,	 the	 R&D	 Advisory	 Board	 and	 Senior	

Steering	Committee	held	periodic	R&D	project	 status	reviews	

throughout the year.

AST FY 2004 R&D Accomplishments 1
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Non-Traditional Flight Safety Systems 

and Integrated Vehicle Health Monitoring 

AST initiated a follow-on study to a report on nontraditional flight safety systems that was completed in FY

2003. Flight safety systems minimize the threat to public safety	

and property posed by a malfunctioning launch vehicle. Nontraditional versions of these systems include autonomous	

and semi-autonomous systems that interface with pilots,	

ground controllers, or both. This follow-on study will apply a	

verification methodology developed in the FY 2003 report to	

an autonomous flight safety system currently being developed	

and tested by NASA.	

To date,AST has conducted initial meetings and developed	

a study plan with its contractor, ITT Industries, headquartered	

inReston, Virginia. ITT will conduct this research and complete	

the research report. Results and lessons learned during this	

trial application will provide AST with insight into the most	

appropriate methods for granting regulatory approval for	

license applications proposing use of these types of	systems.

2 AST FY 2004 R&D Accomplishments 
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Supports FAA Strategic Goal: SAFETY

Human Space Flight Safety

Under a cooperative research effort with the FAA’s Civil	

Aerospace Medical Institute (CAMI) concerning commercial	

human	 space	flight,	 aeromedical	 guidelines	for	 commercial	

launch	 vehicles	 were	 completed.	 The	 CAMI	 is	 the	 medical	

certification,	 research,	 and	 education	 wing	 of	 the	 United	

States	 Department	 of	 Transportation,	 Federal	 Aviation	

Administration’s	 Office	 of	 Aerospace	 Medicine	 located	 at	

the Mike Monroney Aeronautical Center in Oklahoma City,	

Oklahoma.	 Through	 CAMI’s	 National	 Research	 Council	

(NRC) program, a senior researcher worked on this AST R&D	

project	 to	 develop	 minimum	 guidelines	 for	 environmental	

control and life support systems and medical guidelines for	

assuring human survival during commercial launch vehicle	

operations.	

This research effort began in August 2003 and culminates	

in a final report that the CAMI senior researcher delivers to	

AST. Results of this research effort will provide guidance to	

reusable launch vehicle operators who propose to carry crew	

and passengers and assist AST in evaluating such proposals.

AST FY 2004 R&D Accomplishments 3
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Supports FAA Strategic Goal: SAFETY

Structural Inspection Through Bonded 

Thermal Protection Systems

AST continued an FY2003 R&D project to research existing	

and new techniques	for inspecting components covered by	

Thermal Protection	Systems	(TPS). Assuring the health	and	

flightworthiness of reusable launch vehicle (RLV) structures	

is a fundamental concern for the success and safety of future	

commercial space launch ventures. The myriad material- and	

component-level inspection processes performed throughout	

the manufacturing, testing, and service life of these flight	

hardware systems are critical to achieving this assurance.	

Nondestructive evaluation (NDE) methods used for assessing	

the quality of flight structures are among the most vital	

inspection processes. Such methods enable inspection without	

damaging, sampling, or otherwise sacrificing the inspected	

parts. Several NDE techniques are suitable for subassembly	

inspections; however, options narrow as material systems and	

subassemblies are integrated, and accessibility for inspection	

becomes	limited.

Accessibility	 is	 particularly	 relevant	 to	 RLV	 flight	

structures	 covered	 with	 thermal	 protection	 systems.	 These	

systems	 provide	 necessary	 thermal	 barriers	 against	 harsh	

environments imposed during reentry or by other operational	

heatloads. As the external skinofthevehicle,TPSplaya crucial	

role	 in	 protecting	 critical	 structural	 elements.	 The	 design	

and capabilities of TPS vary with location and vulnerability	

of	the	 underlying	 structure.	Examples	 of	 material	 systems	

used for TPS include ablative or durable insulation coatings,	

bonded or sprayed multilayers, flexible blankets, and ridged	

refractory	 tiles.	 These	 TPS	 can	 constrain	 access	 to	 the	

underlying structures for inspection. In some cases, removal	

and reapplication of the TPS may be required to inspect these	

4 AST FY 2004 R&D Accomplishments 
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

structures. Where direct access to critical flight structures is	

unavailable or impractical without damaging the underlying	

structure,	 inspection	 processes	 that	 can	 penetrate	 the	 TPS	

are	 needed.	An	 understanding	 of	 present	 NDE	 capabilities	

also	 serves	 to	 aid	 identification	 and	 guide	 development	 of	

advanced	 NDE	 techniques	 offering	 improved	 potential	 for	

inspection of future RLV structures.

This R&D project was completed in July 2004 when AST	

contractor,	Aerospace	 Corporation	 (El	 Segundo,	 California)	

delivered	 its	 final	 report.	 This	 report	 presents	 a	 brief,	

descriptive	 summary	 of	 various	 NDE	 methods	relevant	 to	

inspecting	 launch	 vehicle	 structures	 covered	 by	 TPS.	 Basic	

issues	 affecting	inspection	 of	 such	 structures	 are	identified.	

Inherent	 strengths	 and	 limitations	 of	 the	 various	 NDE	

techniques as they relate to the projected needs of future RLV	

systems are described.	

AST FY 2004 R&D Accomplishments 5
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Supports FAA Strategic Goal: SAFETY 

Develop and Calibrate a Reentry 

Vehicle Hazard Model

The FAA maintains public safety associated with	

commercial launch vehicle activities by developing safety	

standards and acceptable methods of verification. The FAA/AST

intends to improve public safety regarding commercial space	

launch vehicles by investigating improvements to methods	

of analyzing debris survivability. In FY 2003, AST initiated an	

R&D project to develop a tabular handbook that would allow	

launch and reentry vehicle developers to perform a first-hand	

estimation of casualty expectation (Ec) for the reentry phase	

of missions. In developing this handbook, AST focused on the	

aerothermal demise of the reentry debris analysis process.	

In addition to the development oftheAerothermalAnalysis	

Handbook, AST tasked Aerospace Corporation (El Segundo	

California) to prepare a report addressing the enhancement of	

existing hazard models using the nonmetallic debris fragments	

recovered from the Space Shuttle Columbia’s reentry breakup.

The primary focus will be on using the Columbia debris to	

calibrate existing vehicle breakup scenarios, trajectories, and	

predicted heating	loads.

Results of this research project will help identify public	

safety issues associated with AST-licensed launch and reentry	

activities and mitigate risk to people on the ground caused by	

fallingdebris.In FY2004,Aerospaceproducedadraft handbook	

that will enable an applicant to perform a first estimate of the

Ec for a given mission. This interim report contains survivability	

tables for multiple materials (aluminum, titanium, and steel)	

and shapes (sphere, flat plate, square, and cylinder) as well	

as instructions on how to use the tables. The final report	

is scheduled for completion in February 2005. Because this	

R&D project has reached a sufficient level of maturation, it is	

considered essentially complete and was transitioned to an	

internal AST program.

6 AST FY 2004 R&D Accomplishments 
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Supports FAA Strategic Goal: SAFETY

Radio Frequency Blackout During Reusable 

Launch Vehicle Reentry

A study	 was	 initiated	 to	 increase	 understanding	 of	 the	

high-temperature	 plasmas	 associated	 with	 space	 vehicle	

reentry	 that	 greatly	 affect	 radio	 frequency	 (RF)	 signal	

reception	between	the	vehicle and ground	 controllers. Both	

voice communication and data telemetry between the reentry	

vehicle	 and	 ground	 control	 can	 suffer	 severe	 degradation	

or total loss during the most critical phase of the flight. This	

disruption occurs during an extended period encompassing	

before and after the maximum dynamic pressure phase. The	

resulting radio blackout can block controller communications	

and adversely affect safe	operations.

Three main classes of representative vehicles were chosen	

for study: unpowered lifting glide vehicles, ballistic reentry	

vehicles,	 and	 powered	 air-breathing	 hypersonic	 vehicles.	

Within each of these groups, a number of specific subgroups	

were	 postulated	 that	 represent	 either	 existing	 or	 designed	

vehicles that may experience blackout conditions. Unpowered	

lifting	 glide	 vehicles	 include	the	 Space	 Shuttle	 Orbiter	 and	

several designs for hypersonic boost-glide vehicles, such as	

the crew return vehicle. Ballistic reentry vehicles include sharp	

tip (ballistic missiles) and blunted cone designs (Gemini and	

Apollo reentry capsules). At this time, one private enterprise’s	

reentry	 vehicle	 design,	 the	 Kistler	 Aerospace	 Corporation	

(Kirkland, Washington) K-1, falls within the ballistic reentry	

category, with a blunted cylinder flared at its end. Powered	

air-breathing	 hypersonic	 vehicles	 are	 still	 in	 the	 concept	

development and design	stages.

The study considered two boundary layer, electron density,	

and collision frequency profiles for the sharp-tipped conical	

body,	 one	 at	 low	 altitude	 (15	 kft)	 and	 one	 at	 high	 altitude	

AST FY 2004 R&D Accomplishments 7
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

(154 kft). For the low altitude case, the plasma layer is thin	

and	has	 an	 extremely	high	 collision	frequency	(~150	GHz).

At high altitudes, the plasma layer is thicker, and the collision	

frequency	is	 several	 orders	 of	magnitude	less.	The	 electron	

density	 and	 collision	frequency	 were	reduced	to	 a	data	list	

which	 can	 be	 input	 to	 the	 planar	 code.	 These	 two	 profiles	

were used to determine the reflection from and transmission	

through the plasma over a transmission frequency range from	

0.5 to 50	GHz.

The	 interim	 draft	 report,	 produced	 by	 AST	 contractor,	

Aerospace Corporation (El Segundo, California), addressed	

•	

•	

•	

•	

understanding	of	methods	to	mitigate	communication		

outages	during	reentry	and	enable	controller		

communications	for	operation	within	the	National		

Airspace	System	and	near	space	for	civilian	commercial		

space	reusable	launch	vehicles	operating	within	the		

Space	and	Air	Traffic	Management	System,	

recommendations	on	techniques	for	reduced	RF		

reception	errors	on	reentry	craft	for	Global	Positioning		

System	and	other	RF	navigation	signals,	

recommendations	on	methods	for	uninterrupted			

communications	through	plasma	sheaths,	and	

recommendations	on	requisite	frequency	bands	to		

facilitate	an	AST	decision	on	whether	or	not	to	request		

that	the	Federal	Communications	Commission	reserve		

selected	bands.

The	 final	 report	 is	 scheduled	 for	 completion	 in	 December	

2004.

8 AST FY 2004 R&D Accomplishments 
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Supports FAA Strategic Goal: SAFETY 

Using Orbital Debris Models To Predict 

Safe Reusable Launch Vehicle Reentry 

AST	 initiated	 an	 interagency	 R&D	 effort	 with	 NASA to	

develop a database on the debris recovered from space shuttle	

Columbia. This task seeks to enhance public safety and agency	

efficiency through the development of improved methods for	

public	 risk	 assessments.	 Specifically,	 this	 R&D	 project	 will	

achieve the following	objectives:

•

•

•

Develop a database with detailed information about		

individual fragments recovered from Columbia

Provide an important benchmark comprised of real		

world	data

Facilitate development of credible launch and reentry		

debris models appropriate for hypersonic aerodynamic

break-up conditions	

This	 effort	 responds	 to	 recommendations	 regarding	 air	

travel	 safety	 made	 by	 the	 Columbia Accident	 Investigation	

Board	(CAIB).	The	CAIB	counseled	that	the	aircraft	risk	study	

should	be	 “revisited	 after	the	fragment	data	has	been	fully	

processed”	[CAIB	vol.	II,	page	501].	

In	 addition,	 this	 R&D	 project	 will	 provide	 important	

insights	 necessary	for	the	development	 of	future	 standards	

to	protect	aircraft	during	commercial	launches	and	reentries.	

Several	performance	targets	were	achieved;	AST	

•

•

organized	an	interagency	working	group	dedicated	

to	development	of	a	database	on	Columbia	debris,

established	the	requirements	for	a	database	of		

individual	fragments	recovered	from	Columbia

relevant	to	public	safety	assessments,

AST FY 2004 R&D Accomplishments 9
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

•

•

	established	a	process	for	developing	a	Columbia	debris		

database	by	completing	the	first	Implementation	Plan		

(IP)	under	the	R&D	Memorandum	of	Agreement	with		

NASA	Kennedy	Space	Center,	Florida,	and	

	reached	an	interagency	agreement	with	NASA	to		

provide	funding	to	develop	procedures	for	the		

measurement	and	entry	of	fragment	data.

The quantity of information to be cataloged indicates that	

this effort may require an extended period before completion	

of the database. This long-term effort has been transitioned to	

an internal AST program.

10 AST FY 2004 R&D Accomplishments 
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Supports FAA Strategic Goal: SAFETY 

Assessment of Alternate Methodologies 

for Establishing Equivalent Satisfaction of 

the Expected Casualty Criterion for 

Launch Licensing 

AST completed a report summarizing the review of

an alternate analytical methodology to meet the Expected

Casualty (Ec) criteria for reusable launch vehicles (RLV), as

proposed by the Commercial Space Transportation Advisory

Committee (COMSTAC) RLV Working Group. This FY 2004

R&D project was performed to determine whether this

approach demonstrated a level of safety equivalent to existing

Ec analysis methods. The proposed alternate methodology

derives an allowable catastrophic failure rate for RLVs,

allocates that failure rate to subsystems, and proposes the use

of a Failure Modes, Effects, and Criticality Analysis (FMECA)

to demonstrate that the allocated allowable failure rates

have been met. AST examined the proposed methodology

by investigating the traditional FMECA process, including

its advantages and disadvantages. Current use of FMECA

within the FAA for aircraft certification, expendable launch

vehicle licensing, and RLV licensing was documented. Then,

the proposed process was reviewed and compared to existing

AST processes for determining Ec.

This alternative ties the system safety process directly to

specified reliability goals and is similar to methods used for

commercial aircraft; however, the proposed methodology

suffers drawbacks. Specifically, reliability goals and

reallocations stated in this methodology were derived from

aircraft experience and may not apply to RLVs. Additionally,

this methodology does not include casualty area or population

density.

AST FY 2004 R&D Accomplishments 11
AssociAte AdministrAtor for commerciAl spAce trAnsportAtion 

Failure Modes, Effects, and Criticality Analysis is an

excellent hazard analysis and risk assessment tool, but it

suffers from other limitations. This alternative does not

consider combined failures or typically include software and

human interaction considerations. It also usually provides an

optimistic estimate of reliability. Therefore, FMECA should

be used in conjunction with other analytical tools when

developing reliability estimates.

Results of this research will help AST in the development

of future reliability and risk assessment guidelines in support

of the RLV license evaluation process. While the proposed

alternate methodology does not convincingly demonstrate

a level of safety equivalent to existing Ec analysis methods,

based on this AST study, it presents some concepts for

further consideration. These concepts include setting

vehicle reliability levels in support of system safety and

using analytical methods, such as reliability allocation, to

demonstrate those reliability levels. The resulting final report

recommends that AST investigate setting vehicle reliability

levels as safety criteria and investigate methods that combine

rigorous analytical techniques with limited tests and flight

experience to demonstrate an equivalent level of safety to that

of the existing Ec analysis method.

Supports FAA Strategic Goal: SAFETY 

12 AST FY 2004 R&D Accomplishments