United States Government Accountability Office

GAO Report to Congressional Committees

SPACE 

ACQUISITIONS 

DOD Needs Additional 

Knowledge as it 

Embarks on a New 

Approach for 

Transformational 

Satellite 

Communications 

System 

May 2006 

 

GAO-06-537 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

May 2006

SPACE ACQUISITIONS

DOD Needs Additional Knowledge as it 

Embarks on a New Approach for 

Transformational Satellite 

Communications System 

Highlights of GAO-06-537, a report to 

congressional committees 

The Department of Defense 

(DOD) wants to create a 

networked force where soldiers 

and systems are able to operate 

together seamlessly. To help

facilitate this transformation, 

DOD began the Transformational 

Satellite Communications System 

(TSAT) program in January 2004. 

We reported in 2003 that TSAT 

was about to begin without 

sufficiently mature technology. In 

this report, at your request, we 

followed up with an assessment 

of (1) how the TSAT program is 

progressing, and (2) whether the 

program is using an acquisition 

approach that will provide the 

knowledge needed to enter 

product development. 

What GAO Recommends

We are recommending that, 

before entering product 

development, DOD: (1) reassess 

the value of TSAT in broader 

context of other DOD 

investments, using updated 

knowledge on likely cost, 

schedule, technology, and initial 

capability; (2) update 

requirements in coordination 

with the TSAT user community; 

(3) demonstrate the maturity of 

all critical technologies; and (4) 

establish new cost, schedule, and 

performance goals. In 

commenting on the report, DOD 

agreed with the 

recommendations. 

The Department of Defense is not meeting original cost, schedule, and 

performance goals established for the TSAT program. When the program 

was initiated in 2004, DOD estimated TSAT’s total acquisition cost to be 

$15.5 billion and that it would launch the first satellite in April 2011. TSAT’s 

current formal cost estimate is nearly $16 billion and the initial launch date 

has slipped to September 2014—a delay of over three years. Furthermore, 

while the performance goal of the full five-satellite constellation has not 

changed, the initial delivery of capability will be less than what DOD 

originally planned. After DOD established initial goals for TSAT, Congress 

twice reduced the program’s funding due to concerns about technology 

maturity and the aggressiveness of the acquisition schedule. DOD developed 

the initial goals before it had sufficient knowledge about critical TSAT 

technologies. 

DOD is taking positive steps to lower risk in the TSAT program so it can 

enter the product development phase with greater chance of success.

However, as DOD prepares to implement a new incremental development 

approach for the program, it faces gaps in knowledge that could hamper its 

success. An incremental development will mean reduced capabilities in the 

initial satellites and more advanced capabilities in the remaining satellites. 

Given this change, it will be important for DOD to update requirements in 

coordination with the TSAT user community. While senior DOD officials 

have agreed to these reduced capabilities to get the first satellite launched in 

2014, DOD has yet to reevaluate its investment in TSAT in light of other DOD 

investments using the knowledge it has now gained. Using this new 

knowledge, DOD could be in a better position to set more realistic goals, 

before entering product development. 

Source: Air Force.

www.gao.gov/cgi-bin/getrpt?GAO-06-537.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Mike Sullivan at 

(202) 512-4841 or sullivanm@gao.gov. 
Contents 

Letter 1

Results in Brief 2 

Background 3

DOD Not Meeting Original TSAT Goals 6 

DOD Taking Steps to Lower Program Risk but Additional 

Knowledge Needed Before Product Development 10 

Conclusions 15

Recommendations for Executive Action 16 

Agency Comments 16 

Appendix I Scope and Methodology 18 

Appendix II Comments from the Department of Defense 19 

Appendix III Onboard Signal Processing Technology Heritage 24 

Appendix IV Networking Technology Heritage 25 

Appendix V Lasercom Technology Heritage 26 

Appendix VI Technology Readiness Levels 27 

Tables 

Table 1: Technology Readiness Levels of TSAT Critical 

Technologies 9

Table 2: TSAT Critical Technologies and Their Purposes 13 

Page i GAO-06-537 Transformational Satellite Communications System
Figures 

Figure 1: TSAT System Elements 5 

Figure 2: Changes to Key Milestones in TSAT’s Acquisition 

Schedule 7

Page ii GAO-06-537 Transformational Satellite Communications System
Abbreviations 

ABL Airborne Laser 

ACTS Advanced Communications Technology Satellite 

AEHF Advanced Extremely High Frequency

AISR airborne intelligence, surveillance, and 

 reconnaissance 

ALEX Airborne Lasercom Experiment 

CDR critical design review 

DBRA dynamic bandwidth and resource allocation 

DOD Department of Defense 

DT&E developmental test and evaluation 

EHF extremely high frequency

GIG Global Information Grid

HAIPE High Assurance Internet Protocol Encryptor 

IP Internet protocol 

LES Lincoln Experimental Satellite 

LITE Laser Intersatellite Transmission Experiment 

MDR medium data rate 

MIT Massachusetts Institute of Technology 

NASA National Aeronautics and Space Administration

NGPR next generation processor router 

OSVS Optical Standards Validations Suite 

RF radio frequency 

SHF super high frequency 

SISR space intelligence, surveillance, and 

 reconnaissance 

TCA Transformational Communications Architecture 

TMOS TSAT Mission Operations System 

TRANSEC transmission security 

TRL technology readiness level 

TSAT Transformation Satellite Communications System 

TSOC TSAT Satellite Operations Center 

TSOE TSAT Satellite Operations Element 

XDR+ extended data rate plus 

This is a work of the U.S. government and is not subject to copyright protection in the 

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Page iii GAO-06-537 Transformational Satellite Communications System
United States Government Accountability Office

Washington, DC 20548 

 

May 24, 2006

The Honorable Jeff Sessions 

Chairman, 

Subcommittee on Strategic Forces 

Committee on Armed Services 

United States Senate 

The Honorable Ted Stevens 

Chairman, 

Subcommittee on Defense 

Committee on Appropriations 

United States Senate 

The Department of Defense (DOD) is seeking to transform its 

communication systems to achieve a networked force where soldiers and 

systems are able to operate together seamlessly. To help facilitate this 

transformation, DOD started a new program in January 2004—the 

Transformational Satellite Communications System (TSAT)—with an 

estimated cost of $15.5 billion. Plans call for TSAT to serve as the 

backbone for DOD’s future communications system and to provide critical 

support to weapons systems. A key role envisioned for TSAT is to transfer 

information from DOD’s planned ground-based Global Information Grid 

(GIG), a complex set of programs and initiatives intended to provide users 

with an Internet-like capability for sharing information among military and 

national security users around the world. Through the use of advanced 

technologies, TSAT is slated to transfer higher volumes of information to 

users at a faster rate than current systems, and allow interface with other 

U.S. national security agencies’ satellite-based communications. 

The Department of Defense (DOD) is seeking to transform its 

communication systems to achieve a networked force where soldiers and 

systems are able to operate together seamlessly. To help facilitate this 

transformation, DOD started a new program in January 2004—the 

Transformational Satellite Communications System (TSAT)—with an 

estimated cost of $15.5 billion. Plans call for TSAT to serve as the 

backbone for DOD’s future communications system and to provide critical 

support to weapons systems. A key role envisioned for TSAT is to transfer 

information from DOD’s planned ground-based Global Information Grid 

(GIG), a complex set of programs and initiatives intended to provide users 

with an Internet-like capability for sharing information among military and 

national security users around the world. Through the use of advanced 

technologies, TSAT is slated to transfer higher volumes of information to 

users at a faster rate than current systems, and allow interface with other 

U.S. national security agencies’ satellite-based communications. 

At your request, we followed up our earlier work and assessed (1) the 

TSAT program’s progress toward its cost, schedule, and performance 

goals, and (2) whether the program’s acquisition approach will provide the 

knowledge needed to enter product development. 

At your request, we followed up our earlier work and assessed (1) the 

TSAT program’s progress toward its cost, schedule, and performance 

goals, and (2) whether the program’s acquisition approach will provide the 

knowledge needed to enter product development. 

To conduct our work, we interviewed DOD officials in the National 

Security Space Office, Office of the Director for Program Analysis and 

Evaluation, Office of the Under Secretary of the Air Force, Space and 

Missile Systems Center, and officials from the Massachusetts Institute of 

Technology (MIT) Lincoln Laboratory and the Aerospace Corporation. We

reviewed and analyzed DOD documents related to capabilities, schedule, 

To conduct our work, we interviewed DOD officials in the National 

Security Space Office, Office of the Director for Program Analysis and 

Evaluation, Office of the Under Secretary of the Air Force, Space and 

Missile Systems Center, and officials from the Massachusetts Institute of 

Technology (MIT) Lincoln Laboratory and the Aerospace Corporation. We

reviewed and analyzed DOD documents related to capabilities, schedule, 

Page 1 GAO-06-537 Transformational Satellite Communications System
funding, and technology development efforts, and GAO studies that 

discuss acquisition problems and associated challenges, including our 

decade long body of work on best practices in weapon system 

development. We conducted our review from August 2005 to March 2006 

in accordance with generally accepted government auditing standards. For 

more on our scope and methodology, see appendix I. 

DOD is not meeting original cost, schedule, and performance goals 

established for the TSAT program. When the program was initiated in 

2004, DOD estimated TSAT’s total acquisition cost to be $15.5 billion and 

that it would launch the first satellite in April 2011. TSAT’s current official 

cost estimate is nearly $16 billion, and the initial launch date has slipped to 

September 2014—a delay of over 3 years. Furthermore, DOD has changed

the TSAT program to an incremental development approach and under 

this approach, the initial delivery of capability will be less than what DOD 

originally planned but the performance goal of the full five-satellite 

constellation has not changed. After DOD established initial goals for 

TSAT, Congress reduced the program’s funding in fiscal years 2005 and 

2006 because of concerns about the maturity of critical technologies and

an aggressive acquisition schedule. DOD developed the original goals 

before it had sufficient knowledge about critical TSAT technologies, 

rendering the goals unreliable. In early 2004, when DOD initiated the TSAT

acquisition, only one of seven critical technologies was mature. 

Results in Brief 

DOD is taking positive steps to lower risk in the TSAT program before 

entering the product development phase but as DOD prepares to 

implement a new incremental development approach for the program, it 

faces gaps in knowledge that could hamper the program’s success. To 

lower risk, DOD has separated technology development efforts from

product development and is conducting detailed reviews of the TSAT 

program at critical milestones. Second, DOD has reduced program 

complexity and is incorporating software development best practices for 

the software-intensive ground network that is to interface with DOD’s 

other planned ground networks, such as GIG, to deliver enhanced 

capabilities. Third, DOD plans to demonstrate critical technologies’ 

maturity during key integration tests in fiscal year 2007, before initiating 

product development. Despite these efforts, DOD could improve the 

likelihood of program success by gaining additional knowledge. In 2006, 

DOD directed the TSAT program to follow an incremental development 

approach—a strategy that calls for reduced capabilities in the initial 

satellites and more advanced capabilities in the remaining satellites. This 

approach will likely reduce risks by introducing less new content and 

Page 2 GAO-06-537 Transformational Satellite Communications System
technology in the first two satellites. In light of this change, it will be 

important for DOD to update requirements in coordination with the TSAT 

user community. While senior DOD officials have agreed to reduced 

capabilities up front to increase the confidence in launching the first 

satellite in 2014, DOD has yet to justify the TSAT investment in light of 

other DOD investments using the knowledge it has now gained. Using this 

new knowledge, DOD could be in a better position to establish realistic 

goals for the TSAT program before initiating product development. 

To improve DOD’s transition to transformational communications and 

gain the additional knowledge needed before initiating TSAT product 

development efforts, we are recommending that DOD (1) reassess the 

value of TSAT in the broader context of other DOD investments, using 

updated knowledge on likely cost, schedule, technology, and initial 

capability; (2) update requirements in coordination with the TSAT user 

community; (3) demonstrate the maturity of all critical technologies; and 

(4) establish new cost, schedule, and performance goals. In written 

comments on a draft of this report, DOD concurred with our 

recommendations, and we have incorporated detailed comments where 

appropriate (DOD’s letter is reprinted in app. II). 

Present and evolving threats highlight the need to design, operate, and 

defend military communication networks to ensure continuity of joint 

operations. However, current systems lack the connectivity, capacity, 

interoperability, control, adaptability, availability, and coverage to support 

military action. To address these shortcomings, DOD is moving toward 

network-centric communication systems to facilitate critical 

communication. A key system in this concept is TSAT—one of DOD’s most 

complex and expensive space programs involving the integration of 

multiple, complex technologies never before integrated in a single space 

system. 

Background 

As early as 2001, DOD had developed a new Transformation 

Communications Architecture (TCA) to guide the implementation of 

emerging communications technologies. The TCA is an element of a 

broader global information network or grid, DOD’s overarching vision to 

provide authorized users with a secure and interconnected information 

environment. The performance parameters for the GIG define the 

fundamental requirements for the systems to be interconnected through 

the TCA. The TCA is designed to realize the benefits of an Internet 

protocol (IP) environment, as it will provide instant accessibility to the 

military and intelligence communities. The goal of the TCA is to provide 

Page 3 GAO-06-537 Transformational Satellite Communications System
accessibility to all users while removing communications constraints 

related to capacity, control, and responsiveness. It is composed of 

elements in ground stations, aboard tactical vehicles, and in space. 

TSAT is the space-based network component of the TCA that is expected

to provide survivable, jam-resistant, global, secure, and general purpose 

radio frequency and laser cross-links with air and other space systems. 

Some of the satellite technologies TSAT will employ have been evolving 

for over 25 years. TSAT is building on these heritage technologies in three 

primary areas: onboard signal processing for protection and connectivity, 

networking, and space laser communication. Through these advanced 

technologies, TSAT will improve communications to DOD, intelligence 

community, and homeland defense users by transmitting large amounts of 

data at a faster rate. Further, TSAT is designed to vastly improve satellite 

communications by extending the GIG to users without ground 

connections and making it possible for users to travel with small terminals 

and communicate while on the move. 

The TSAT system will consist of a five-satellite constellation (with a sixth 

satellite for backup), the TSAT satellite operations element (TSOE) which 

includes a primary TSAT satellite operations center (TSOC) for on-orbit 

satellite control, a backup TSOC, and a set of transportable units, a TSAT 

Mission Operations System (TMOS) to provide network management, and 

ground gateways (see fig. 1). 

Page 4 GAO-06-537 Transformational Satellite Communications System
Figure 1: TSAT System Elements 

Source: Air Force.

DOD has awarded four TSAT contracts through separate bidding 

processes. In 2003 DOD awarded a contract to Booz Allen Hamilton for 

overall systems engineering and integration. DOD also awarded two 

separate contracts to competing contractor teams—Lockheed Martin 

Space Systems/Northrop Grumman Space Technology and Boeing Satellite 

Systems—to conduct risk reduction efforts and present development plans 

for the TSAT satellites. DOD expects to award a contract to one of these 

contractor teams in 2007 to design and build the satellites. Finally, in 

January 2006 DOD awarded a $2 billion contract to Lockheed Martin 

Integrated Systems and Solutions to develop TMOS and the overall 

network architecture. This network development contractor is responsible 

for negotiating the interfaces between the TSAT network and the space

segment, user terminals, and other external networks. 

Page 5 GAO-06-537 Transformational Satellite Communications System
Recently, DOD changed the TSAT acquisition strategy to an incremental 

development approach. This approach establishes time-phased 

development of new products in increments. The first increment 

incorporates technology that is already mature or can be matured quickly. 

As new technologies become mature, they are incorporated into 

subsequent increments so that the product’s capability evolves over time. 

This approach also reduces risks by introducing less new content and 

technology into a design and development effort, an approach intended to 

enable developers to deliver a series of interim capabilities to the 

customer more quickly. As such, incremental development is considered a 

best practice for successful DOD and commercial development programs 

because it allows these programs to make cost and schedule estimates 

that are based on mature technologies. Recognizing the benefits of 

evolving space systems, DOD included the incremental development of 

space systems in its revised National Security Space acquisition policy. 

DOD is not meeting its original cost, schedule, and performance goals for 

the TSAT program. TSAT’s cost has increased by over $420 million, the 

planned launch date for the first satellite has slipped more than 3 years, 

and the satellites will be less capable than originally planned. Since DOD 

established initial goals for the program, Congress has twice reduced the 

program’s annual budget and directed DOD to spend more time 

developing and proving critical technologies. DOD developed the initial 

goals with limited knowledge, when almost all of the critical technologies 

had yet to be proven to work as intended. As a result, the goals were 

developed without a high level of reliability. 

When DOD started the TSAT program in January 2004, it estimated the 

total acquisition cost to be about $15.5 billion. TSAT’s acquisition cost had

increased to nearly $16 billion by the end of 2004.1 DOD also originally 

scheduled critical design review (CDR) for April 2008 and the first TSAT 

satellite launch in April 2011. CDR is now scheduled for September 2010 

and the first launch in September 2014—delays of approximately 29 and 41 

months, respectively. In addition, DOD recently changed its TSAT 

acquisition strategy to an incremental approach by deciding to build the 

first two satellites with fewer capabilities and delaying the more advanced 

DOD Not Meeting 

Original TSAT Goals 

Initial Goals for TSAT Were 

Based on Limited 

Knowledge 

 1

 At the time of this report, the 2005 end-of-year cost data and a new program baseline were 

unavailable. 

Page 6 GAO-06-537 Transformational Satellite Communications System
capabilities for the later satellites in the program. While the initial two 

satellites will not perform as originally planned, the full five-satellite 

system will still meet the original user requirements, according to program 

officials. 

According to program officials, the original goals for TSAT have been 

revised several times as a result of reductions in program funding. After 

DOD set its initial goals for TSAT, Congress twice funded the program at 

levels below DOD’s request (in fiscal years 2005 and 2006) because of 

concerns about the state of technical maturity for key subsystems and an 

aggressive schedule for acquisition. During this time, Congress also 

directed the program to focus on the challenges of integrating the 

technologies needed for the system. Figure 2 shows the changes to key 

milestones dates in TSAT’s acquisition schedules. The program recently 

was directed to develop a new total acquisition cost estimate at a higher 

level of confidence—which could further increase the amount of funding 

requested in the near term for the program.2

 However, as of April 2006, 

DOD had yet to develop this new estimate. 

Figure 2: Changes to Key Milestones in TSAT’s Acquisition Schedule

Current Schedule Estimate

Preliminary 

design

review

(3/09)

Critical 

design

review

(9/10)

Initial 

Operational 

Capability

(2016)

KDP-B 

(Program initiation)

(1/04)

First TSAT 

launch

(9/14)

Original Schedule Estimate

Preliminary 

design

review

(Data not available)

Critical 

design

review

(4/08)

First TSAT 

launch

(4/11)

Initial 

Operational 

Capability

(10/13)

KDP-B 

(Program initiation)

(1/04)

Current Schedule Estimate

Preliminary 

design

review

(3/09)

Critical 

design

review

(9/10)

Initial 

Operational 

Capability

(2016)

Initial 

Operational 

Capability

(2016)

KDP-B 

(Program initiation)

(1/04)

KDP-B 

(Program initiation)

(1/04)

First TSAT 

launch

(9/14)

First TSAT 

launch

(9/14)

Original Schedule Estimate

Preliminary 

design

review

(Data not available)

Preliminary 

design

review

(Data not available)

Critical 

design

review

(4/08)

Critical 

design

review

(4/08)

First TSAT 

launch

(4/11)

First TSAT 

launch

(4/11)

Initial 

Operational 

Capability

(10/13)

Initial 

Operational 

Capability

(10/13)

KDP-B 

(Program initiation)

(1/04)

KDP-B 

(Program initiation)

(1/04)

Source: Air Force (data); GAO (presentation).

 2

 DOD originally estimated the TSAT program cost using a 50 percent confidence level, 

which meant that the program had a 50 percent chance of being completed under or over

budget. DOD is changing to an 80 percent confidence level in its next estimate which 

should result in a higher, more accurate, program cost estimate. 

Page 7 GAO-06-537 Transformational Satellite Communications System
When DOD established initial goals for the TSAT program, it lacked 

sufficient knowledge about key critical technologies. Our past work has 

shown that a knowledge-based model leads to better acquisition 

outcomes.3

 This model can be broken down into three cumulative 

knowledge points for technology maturity, design maturity, and 

production maturity. At the first knowledge point, a match is made 

between a customer’s requirements and the product developer’s available 

resources in terms of technical knowledge, time, money, and capacity. We 

have also reported that starting a complex program like TSAT with 

immature technologies can lead to poor program performance and 

outcomes. 

In early December 2003, we reported that the Air Force would have 

difficulty establishing goals when starting the TSAT program because 

critical technologies were underdeveloped and early design studies had 

not been started. 4 At that time, we recommended that the Air Force delay 

the start of the TSAT program until technologies had been demonstrated 

to be at an acceptable level of maturity and to consider alternative 

investments to TSAT. One month later DOD started the program with only 

one of the seven critical technologies mature, and could not have known 

with any certainty what resources would be needed to eventually meet 

users’ requirements, despite having confidence in its technology 

development schedule. 

For the TSAT program, the Next Generation Processor Router (NGPR) 

and laser communications are the highest-risk areas. Program officials 

reported that three of the critical technologies in the NGPR are involved 

with the transmission of data: (1) packet processing payloads, (2) dynamic 

bandwidth and resource allocation (DBRA), and (3) protected bandwidth 

efficient modulation using high data rates. The use of these Internet-like 

processes will provide unprecedented connectivity for all TSAT users by 

moving from an older circuit-based network (similar to telephone) to the 

newer IP-based network (similar to the Internet). Additionally, DOD 

continues to develop the technologies that are needed for laser 

 3

 See GAO, Defense Acquisitions: Space-Based Radar Effort Needs Additional Knowledge

before Starting Development, GAO-04-759 (Washington, D.C.: July 23, 2004).

4

 See GAO, Space Acquisitions: Committing Prematurely to the Transformational Satellite 

Program Elevates Risks for Poor Cost, Schedule, and Performance Outcomes, GAO-04-71R

(Washington, D.C.: Dec. 4, 2003). 

Page 8 GAO-06-537 Transformational Satellite Communications System
communications. Table 1 identifies the level of maturity of TSAT critical 

technologies at program start and their expected maturity dates. 

Table 1: Technology Readiness Levels of TSAT Critical Technologies 

Critical technology

TRL level at

 development starta

TRL level as 

 of March 2006 

Expected

maturity dateb

Communication-on-the move antenna 4 6 N/A

Packet Processing Payload 6 6 N/A

Bandwidth Efficient Modulation (XDR+) 3 5 2007

Dynamic Bandwidth Resource Allocation (DBRA) 3 5 2007

Information Assurance – TRANSEC 3 6 N/A

Information Assurance – HAIPE 4 6 N/A

Single-Access Lasercom 5 5 2007

Multi-Access Lasercomc

Narrow field of view 

Wide field of view 2 2 to be determined

Source: Air Force (data); GAO (analysis). 

 N/A: not applicable 

a

TRL levels might vary in maturity among the viable suppliers. 

b

These dates might vary depending on the viable supplier and refer to the original acquisition 

approach; they could be different for an incremental approach, as resources are restructured. 

c

Multi-Access Lasercom is shown here for context only. The TSAT program is being restructured and

this technology is no longer part of the baseline TSAT program. 

To minimize the potential for technology development problems after the 

start of product development, DOD uses an analytical tool to assess 

technology maturity. This tool associates technology readiness levels 

(TRL) with different levels of demonstrated performance, ranging from 

paper studies to actual application of the technology in its final form. For 

TSAT, the space segment contractors are using a series of events to 

demonstrate and integrate the critical technologies into subsystems and 

then testing to determine the extent the components function properly 

together. The maturity levels of the critical technologies for TSAT 

currently range from TRL 5 to 6, with the remaining technologies needing 

integration testing to demonstrate maturity. (See app. VI for a description 

of the TRL levels.) 

According to program officials, these technologies will be demonstrated at 

TRL 6 when key integration tests are completed in fiscal year 2007. The 

two main tests facing the program are the second series of integration 

Page 9 GAO-06-537 Transformational Satellite Communications System
testing on the Next Generation Processor Router and Optical Standards 

Validation Suite (NGPR-2 and OSVS-2). Program officials said that the 

program is using these independent tests to reduce risk by uncovering 

technical problems before awarding the space segment contract for the 

design and assembly of the satellites. The results of the tests are to be 

assessed at the second interim program review before DOD makes a 

decision to enter the product development phase of the program. At the 

time of this report, results from the first series of integration tests were 

unavailable.

DOD is taking positive steps to lower TSAT program risk, but additional 

knowledge is needed before entering product development. DOD is 

separating its technology development efforts from product development,

continuing to conduct program reviews before making key decisions, 

reducing program complexity by staggering the awards on its ground and 

space segment contracts, and incorporating knowledge-based metrics in 

software development. Additionally, DOD is reducing risks in technology 

development efforts by leveraging decades of knowledge on heritage 

systems and using independent integration tests to demonstrate the 

maturity of critical technologies. Despite these efforts, DOD faces gaps in

knowledge that could hamper successful outcomes. As DOD implements 

an incremental approach for the TSAT program, it has yet to justify the 

TSAT investment in light of other DOD investments using the knowledge it

has now gained. 

DOD is reducing TSAT program risk in the following ways: 

• Separating technology and product development—DOD is separating 

technology development from product development and plans to prove 

that all critical technologies will work as intended before the TSAT 

program enters product development in 2007. In the past, DOD has not 

successfully implemented acquisition best practices in its space 

programs to reduce risks and increase the likelihood of better 

outcomes, particularly in some of its larger and more complex 

programs. We previously reported that DOD could curb its tendency to 

over-promise the capabilities of a new system and to rely on immature 

technologies in part by separating technology development from 

DOD Taking Steps to 

Lower Program Risk 

but Additional 

Knowledge Needed 

Before Product 

Development 

Efforts Under-Way Reduce 

Program Risk 

Page 10 GAO-06-537 Transformational Satellite Communications System
product development (system integration and system demonstration). 5

According to program officials, the TSAT program will not start 

building the TSAT system until all critical technologies needed for the 

system to satisfy user requirements are mature, ensuring a clear 

demarcation between the two phases of system development. This 

approach better enables decision makers to determine if a match exists 

between TSAT requirements and available resources (time, technology, 

capacity, and funding). 

• Conducting program reviews—DOD plans to continue conducting 

reviews of the TSAT program at key milestones to reduce program risk. 

DOD’s space acquisition policy requires that program managers hold 

milestone reviews or independent program assessments as a program 

is nearing key decision points. Following this guidance, the TSAT 

program’s acquisition schedule requires the program manager to assess 

program knowledge at specific points. The next major milestone is 

scheduled for the fourth quarter of fiscal year 2007, when the program 

will hold an interim program review to assess the program’s readiness 

to proceed into the product development phase. Importantly, this 

review will include an assessment of the maturity levels of the critical 

technologies. Part of this review will involve the use of independent 

cost estimators as a way to develop an unbiased, consistent, and 

objective total cost estimate for the program. 

• Reducing ground and space segment complexity—DOD has lessened 

the likelihood of problems in development by reducing the complexity 

of the program. Specifically, according to program officials, the 

contract for ground-based network operations was awarded before the 

space segment contract so that the competing space segment 

contractors could work toward a stable and more mature network 

design. In January 2006, DOD awarded a TMOS contract worth $2 

billion to Lockheed Martin Integrated Systems and Solutions to start 

developing the overall network architecture and TMOS. Awarding this 

contract first will allow the competing space contractors to focus their 

satellite designs on a single architecture and mission operations 

system, thereby reducing program complexity. 

 5

 See GAO, Defense Acquisitions: Improvements Needed In Space Systems Acquisition 

Policy to Optimize Growing Investment in Space, GAO-04-253T (Washington D.C.: July 

12, 2005); and GAO, Military Space Operations: Planning, Funding, and Acquisition 

Challenges Facing Efforts to Strengthen Space Control, GAO-02-738 (Washington, D.C.: 

Sept. 23, 2002). 

Page 11 GAO-06-537 Transformational Satellite Communications System
• Incorporating software best-practices—Our review of the 

development plans for the software-intensive TMOS segment that is to 

interface with other networks like the GIG shows that DOD is also 

incorporating best practices in this area to mitigate program risks. Our 

previous work has identified and reported on three fundamental 

management strategies that are best practices for software 

development: (1) implementing an evolutionary approach, (2) following 

disciplined development processes, and (3) collecting and analyzing 

meaningful metrics to measure progress.6

 First, the evolutionary 

approach includes setting requirements, establishing a stable design, 

writing code, and testing. Second, successful acquisitions require that 

developers demonstrate they have acquired the right knowledge before 

proceeding to the next development phase. Finally, metrics such as 

costs, schedule, size of a project, performance requirements, testing, 

defects, and quality provide evidence that the developer has acquired 

appropriate knowledge in moving from one phase to another. Although 

DOD’s software acquisition plans may incorporate these best practices, 

the potential for cost and schedule increases because of unforeseen 

software complexity is inherent in the development of a large quantity 

of software, as is needed for TSAT. To manage this risk, program 

officials stated that extensive and fully funded mitigation plans are in 

place and that the network contractor will be held to the best practices 

through program oversight and reporting. 

Heritage Technologies and 

Independent Tests Reduce 

Program Risk 

To reduce risk while developing the critical technologies for TSAT, DOD is 

leveraging decades of existing knowledge from heritage systems. For 

TSAT to be successful, DOD will have to integrate technologies that have 

been proven to work in other space systems, but now must be integrated 

into a single communication system. Officials at MIT’s Lincoln Laboratory, 

who are responsible for the independent testing and verification of TSAT 

technologies, stated that there are no fundamental discoveries or 

breakthroughs involved with developing TSAT. Rather, the enabling 

technologies build upon architectures and technologies developed across 

decades of space programs or experiments. However, officials at the 

Aerospace Corporation who are working closely with the TSAT program 

stated that there are risks involved in using heritage technologies—

primarily integration risks—because the technologies must still be tested 

 6

 See GAO, Defense Acquisitions: Stronger Management Practices Are Needed to Improve 

DOD’s Software-Intensive Weapon Acquisitions, GAO-04-393 (Washington, D.C.: Mar. 1,

2004). 

Page 12 GAO-06-537 Transformational Satellite Communications System
and evaluated to determine if they will work together as intended. The 

three main TSAT enabling technologies are onboard signal processing, 

networking, and laser communications. See table 2 below for a list of the 

critical technologies and a description of their purposes. 

Table 2: TSAT Critical Technologies and Their Purposes 

Critical technology Purpose

Communication-on-the move antenna Provide satellite to ground link using a 1-foot

antenna for mobile assets. 

Packet Processing Payload Convert incoming analog radio signals into an

Internet-like packet of digital data and then 

interpret the header on the data and pick the 

correct Internet-like address that is to receive 

the data packet. 

Bandwidth Efficient Modulation

(extended data rate plus: XDR+) 

Provide a set of radio frequency waveforms to 

transfer data from the satellite.

Dynamic Bandwidth and Resource 

Allocation 

Algorithm used to choose which radio 

frequency waveform (XDR+) to use, depending 

on what speed the data need to be sent; 

determined by such factors as environmental

conditions on the ground (e.g., urban, desert,

trees, etc.). 

Information Assurance (transmission 

security: TRANSEC) 

TRANSEC algorithms and keys that provide 

transmitted signal cover to avoid detection, 

identification, and exploitation (such as traffic 

analyses.) 

Information Assurance (highassurance IP encryptor: HAIPE) Inline Network Encryptor devices to protect 

user data. 

Single-access lasercom Use of a single telescope, optical module, 

high-power optical power amplifier, and 

modem to transport data along a laser carrier

from one location to another. 

Source: Air Force (data); GAO (presentation). 

TSAT is building upon the onboard signal processing developments in 

military satellite communications that started in the mid-1970s. These 

developments initially focused on providing highly robust 

communications, but over time have evolved to increased capacity and 

bandwidth, as well as enhanced efficiency. For example, the Lincoln 

Experimental Satellites (LES) 8 and 9, Milstar I and II, and Advanced 

Extremely High Frequency (AEHF) system have verified the onboard 

processing capabilities that will be used in TSAT. 

According to officials at the Lincoln Laboratory, much of the required 

technology for the network services for TSAT comes directly from the 

Page 13 GAO-06-537 Transformational Satellite Communications System
ground-based Internet. Further, TSAT is building on the successful 

achievements of previous space programs like DOD’s Milstar and AEHF 

satellites, the National Aeronautics and Space Administration’s (NASA)

Advanced Communications Technology Satellite (ACTS), and the 

Spaceway and Astrolink satellites from the commercial sector. 7 In addition 

to space-based signal processing, the TSAT satellites will use packet 

routing in space, faster data transmission, and Internet-like data 

transmission formats to produce the networking capability to extend 

worldwide network services to the user. 

TSAT will use high-rate laser communications to connect TSAT satellites 

into a global network and to provide readout from other space- and airborne intelligence, surveillance, and reconnaissance (SISR/AISR) assets. 

According to Lincoln Laboratory officials, many of the needed 

components for TSAT’s laser communications are versions from 

commercial optical networking. A series of three systems developed by

Lincoln Laboratory (Lincoln Experimental Satellites (LES) 8 and 9, Laser

Intersatellite Transmission Experiment (LITE) and LITE-2, and GeoLITE) 

have and continue to demonstrate laser capabilities needed for TSAT. 

Moreover, recent programs like Lincoln Laboratory’s Airborne Lasercom

Experiment (ALEX) are providing knowledge about how TSAT’s laser 

communications can be used to support AISR assets, and DOD’s Airborne

Laser (ABL) is helping scientist to characterize certain limits of laser 

capabilities in atmospheric conditions, according to the officials. 

Appendixes III through V further highlight the history of the technology 

heritage being applied to TSAT. 

Remaining Gaps in 

Knowledge Could Hamper 

Successful Outcomes 

Despite these positive steps to lower program risks, DOD faces gaps in 

knowledge, as it begins to implement its new development approach, that 

could impede TSAT’s success. In 2006, DOD directed the program to 

follow an incremental development approach, changing the contents of 

the program. Under this approach, the program will deliver less capability 

in the first two satellites, and then more advanced capabilities as 

technologies mature and are incorporated into the remaining satellites. 

DOD has not fully assessed the value of the TSAT investment in light of 

major changes to the program. 

 7

 Although the Astrolink system was never launched, the first payload was essentially 

complete before the launch was canceled. 

Page 14 GAO-06-537 Transformational Satellite Communications System
Historically, many new development programs in DOD have sought to 

quickly gain the latest capabilities,8

 but because the technologies were not 

mature enough to make such leaps, programs were often in development 

for years while engineers continued to develop and mature the needed

technologies. This increased both the time and cost required to develop

the systems. An incremental approach, on the other hand, reduces risks by 

introducing less new content and technology into a design and 

development effort. The incremental approach for TSAT allows more time 

for the development of higher-performing capabilities, thereby potentially

increasing the level of confidence in the launch date of the first satellite, 

planned for 2014. High-level DOD officials have agreed to these reduced

capabilities up front, so the TSAT program now plans to deliver satellites

that meet user requirements in an evolutionary manner. 

Notwithstanding the approval for the revised TSAT program from senior 

DOD officials, DOD has yet to justify the TSAT investment in light of other 

DOD investments using the knowledge it has now gained on cost, 

schedule, and initial capabilities to be delivered. For example, TSAT’s cost 

estimate has increased and the initial satellites will be less capable than 

originally expected. Furthermore, it is imperative, given the recent 

changes to the program, that DOD work with the TSAT user community to 

update requirements to ensure the timely delivery of promised capabilities. 

Finally, it does not appear that DOD has completely addressed all the 

unknowns concerning the relationship between TSAT and two of DOD’s 

other expensive and complex systems, namely the GIG and Space Radar. 

For example, work still remains in finalizing the requirements for these 

systems and understanding how the incrementally developed TSAT will 

satisfy the needs. 

DOD has taken action to put itself in position to prove out critical 

technologies before initiating satellite development—an approach not 

typically seen in DOD’s space programs. DOD has taken further action to 

reduce program risk by changing to an incremental development 

approach. While this approach will reduce the capability of the first two 

satellites, it is a positive step in reducing program risk because the 

program will gain additional technical knowledge before integrating the 

more advanced technologies into the satellites. Even though DOD is taking 

Conclusions 

 8

 See GAO, Missile Defense: Knowledge-Based Practices Are Being Adopted, but Risks

Remain, GAO-03-441 (Washington, D.C.: Apr. 30, 2003). 

Page 15 GAO-06-537 Transformational Satellite Communications System
such positive steps, TSAT is still expected to be one of the most ambitious, 

expensive, and complex space systems ever built. TSAT is being designed

to transform military communication using Internet-like and laser 

capabilities—key integrations risks. Other weapon systems are to 

interface with it and will be highly dependent on it for their own success. 

While DOD is planning to undertake new systems, such as TSAT, broader 

analyses of the nation’s fiscal future indicate that spending for weapon 

systems may need to be reduced, rather than increased, given the 

constrained fiscal environment. Given these challenges and fiscal 

realities, it is prudent for DOD to reexamine the value and progress of 

TSAT before committing to building the full constellation of 

communication satellites. 

To improve DOD’s transition to transformational communications by 

gaining the additional knowledge it needs before TSAT enters product 

development, we recommend that the Secretary of Defense direct the 

Under Secretary of the Air Force to take the following four actions: 

• Reassess the value of TSAT in the broader context of other DOD 

investments, using updated knowledge on likely cost, schedule, 

technology, and initial capability;

• Update requirements in coordination with the TSAT user community; 

• Prove that all critical technologies will work as intended; and 

• Establish new cost, schedule, and performance goals for the program 

once the above knowledge has been gained.

We provided a draft of this report to DOD for review and comment. DOD 

concurred with our recommendations and provided detail comments, 

which we have incorporated where appropriate. DOD’s letter is reprinted 

as appendix II. 

We plan to provide copies of this report to the Secretary of Defense, the 

Secretary of the Air Force, and interested congressional committees. We 

will also provide copies to others on request. In addition, the report will be 

available on the GAO website at http://www.gao.gov. 

Recommendations for 

Executive Action 

Agency Comments 

Page 16 GAO-06-537 Transformational Satellite Communications System
If you or your staff has any questions concerning this report, please 

contact me at (202) 512-4841 or sullivanm@gao.gov. Contact points for our 

Offices of Congressional Relations and Public Affairs may be found on the 

last page of this report. Key contributors to the report are Arthur Gallegos, 

Assistant Director, Tony Beckham, Noah B. Bleicher, G. Martin Campbell, 

Sharron Candon, Claire Cyrnak, Maria Durant, and Hai V. Tran. 

Michael J. Sullivan 

Director, Acquisition and Sourcing Management 

Page 17 GAO-06-537 Transformational Satellite Communications System
Appendix I: Scope and Methodology Appendix I: Scope and Methodology 

To assess the Department of Defense’s (DOD) progress toward achieving 

cost, schedule and performance goals for the Transformational Satellite 

Communications System (TSAT), we collected and reviewed (1) budget 

and expenditure plans, (2) acquisition planning documents, and (3) 

technology and readiness information to determine if the program was 

meeting its original goals. We compared changes in cost and schedule to

original estimates and evaluated DOD’s plans for maturing the critical 

technologies against best practice standards to determine if they will 

sufficiently mature when DOD plans to start product development. We 

discussed this information with DOD officials in the Office of the 

Secretary of Defense, Program Analysis and Evaluation, Crystal City, 

Virginia; National Security Space Office, Chantilly, Virginia; Space and 

Missiles Systems Center, Los Angeles Air Force Base, California; and with 

officials at the Massachusetts Institute of Technology (MIT) Lincoln 

Laboratory, Boston, Massachusetts; and the Aerospace Corporation, El 

Segundo, California. 

To determine if the TSAT program is using an acquisition approach that 

will provide the knowledge it needs to proceed to product development, 

we collected and reviewed documents that described the TSAT program’s 

plans to build knowledge and to mitigate risks. We reviewed detailed 

documents related to capabilities, schedule, funding, and technology 

development for the revised acquisition strategy. We considered DOD’s 

current knowledge-building activities against DOD and GAO studies that 

discuss acquisition problems and associated challenges with acquisition 

programs—including work on best practices in weapon system 

development that we have conducted over the past decade. We analyzed

the extent to which the TSAT program is using a knowledge-based 

approach to technology and product development. To do this, we focused 

on the whether the new acquisition approach will meet user requirements 

and match those needs to resources. We discussed DOD plans and efforts 

to meet user’s needs with DOD officials in the Military Satellite 

Communication Joint Program Office, Los Angeles Air Force Base, 

California; Directorate of Space Acquisition, Office of the Under Secretary 

of the Air Force, Arlington, Virginia; and Office of the Assistant Secretary 

of Defense (Networks and Information Integration), Arlington, Virginia. 

We performed our work from August 2005 through March 2006 in 

accordance with generally accepted government auditing standards. 

Page 18 GAO-06-537 Transformational Satellite Communications System
Appendix II: Comments from the Department Appendix II: Comments from the Department of Defense 

of Defense 

Page 19 GAO-06-537 Transformational Satellite Communications System
Appendix II: Comments from the Department 

of Defense 

Page 20 GAO-06-537 Transformational Satellite Communications System
Appendix II: Comments from the Department 

of Defense 

Page 21 GAO-06-537 Transformational Satellite Communications System
Appendix II: Comments from the Department 

of Defense 

Page 22 GAO-06-537 Transformational Satellite Communications System
Appendix II: Comments from the Department 

of Defense 

Page 23 GAO-06-537 Transformational Satellite Communications System
Appendix III: Onboard Signal Processing Appendix III: Onboard Signal Processing Technology Heritage 

Technology Heritage 

Time frame Program title Purpose/mission Relevance to TSAT

Mid-1970s Lincoln Experimental

Satellites (LES) 8 and 9 

First satellites to use onboard signal processing, 

spread spectrum techniques (frequency hopping) 

to demonstrate protected military satellite 

communications, and radio frequency (RF)

crosslink capability. 

Onboard signal processing; 

spread spectrum satellite 

communications; and satellite-tosatellite crosslinks. 

Mid-Late 1980s Fleet Satellite

Communications System 

(FLTSATCOM) EHF 

Packages: FEP 

Built by MIT Lincoln Laboratory and hosted on the 

operational FLTSATCOM satellites 7 and 8 (built 

by TRW). These packages provided the first 

satellite communications at extremely high 

frequency (EHF) on the uplink and super high 

frequency (SHF) on the downlink. 

Multichannel onboard signal 

processing; EHF/SHF spread 

spectrum satellite 

communications; and onboard

control for circuit switching. 

Early 1990s Milstar I Satellites provided the first strategic/tactical

operational satellite using the EHF/SHF. Satellites 

also provided narrower spot beam coverage and 

electronically agile beam coverage to provide

enhanced service to small, dispersed user 

terminals. 

Combined strategic/tactical

service at EHF, narrow beam 

antenna coverage, electronically 

steered antenna coverage; and 

intersatellite crosslinks. 

Late 1990s Milstar II Satellites provided enhanced capacity and 

protection through the addition of a medium data 

rate (MDR) payload through narrow spot beam 

antennas. Satellite capacity was more than 10

times greater than Milstar I. 

Extension of EHF waveform to 

higher rates. improved protection 

via active antenna discrimination 

(nulling). 

2005 Advanced EHF (AEHF) The Advanced EHF (AEHF) system provides a 

further increase in the capability of EHF satellite 

communications by increasing both the total 

satellite throughput by another factor of 10 and by 

increasing the data rate available to individual 

terminals. The extended data rate (XDR) 

waveform supports data rates from 75 to 

8,192,000 bytes per second for individual 

terminals. 

Binary bandwidth efficient 

waveforms for EHF, improved 

support for small terminals, and 

onboard processing technologies 

for increased satellite throughput. 

Source: MIT Lincoln Laboratory. 

Page 24 GAO-06-537 Transformational Satellite Communications System
Appendix IV: Networking Technology Appendix IV Heritage : Networking Technology 

Heritage 

Time frame Program title Purpose/mission Relevance to TSAT

1980s Milstar and AEHF The Milstar satellites were the first 

satellite payloads to use onboard 

processing and onboard switching of 

user signals. The AEHF system further 

developed space-based signal

processing technology, providing more 

capacity and higher data rates.

Space-based signal processing; 

quickly reconfigurable circuit setup, 

teardown, and switching; packetover-circuit transmission to/from 

geosynchronous orbit 

1990s NASA Advanced

Communications Technology 

Satellite (ACTS) 

This satellite produced many important 

studies of networking protocol behavior 

(such as Transmission Control 

Protocol/Internet Protocol: TCP/IP) in a 

combined space and terrestrial

environment. 

Provided performance 

measurements for IP, and increased

the class payload processing rate to 

more than 100 megabytes per

second. 

2000s Spaceway and Astrolink These are the first satellites designed to 

perform packet switching in space. The 

Astrolink system was never launched 

because of a sudden market downturn in 

the telecommunications industry. 

However, the first payload was 

essentially completed before market 

conditions caused cancellation of the 

deployment. The first Spaceway satellite 

is now onorbit and operational, and 

launch of the second is planned in the 

near future. 

Lessons include how to build packet 

processing and routing hardware 

and software for use in space in the 

gigabytes per second data rate

class. 

Source: MIT Lincoln Laboratory. 

Page 25 GAO-06-537 Transformational Satellite Communications System
Appendix V: Lasercom Technology Heritage Appendix V: Lasercom Technology Heritage 

Time frame Program title Purpose/mission Relevance to TSAT

1975 Lincoln Experimental Satellites 

(LES) 8 and 9 

The LES-8/9 satellites built by Lincoln 

Laboratory in the mid-1970’s were originally 

slated to use lasercom crosslinks. The 

development of these crosslinks was impaired

by the lack of an industry base for the 

necessary optical components and was 

abandoned in favor of RF links. 

Development of a fiber-based

architecture, and use of spacequalified commercial fiber-optic

components. 

1980s-1990s LITE and LITE-2 The LITE lasercom terminal developed by 

Lincoln Laboratory was able to capitalize on

commercial parts to leverage its large-scale 

production processes. In the early 1990s, as

commercial fiber optic components became 

available, the LITE-2 terminal was developed. 

It used a new fiber-based architecture with 

remote optics. The ability to remote the 

telescope and other free space optics from the 

High Power Optical Amplifier and modem 

dramatically simplifies spacecraft integration. 

Telescope, optical module, fiberbased high power optical 

amplifier, modem, and high-rate 

lasercom. 

Late 1990s GeoLITE Built in the late 1990’s by Lincoln Laboratory 

and flown aboard a Northrop-Grumman (TRW) 

satellite. The GeoLITE experiment (launched in 

2001) used the fiber-based architecture 

developed under the LITE-2 program. The 

lasercom payload continues to send telemetry 

from critical subsystems that provide insight 

into the lifetime of optical components in space. 

Same as in LITE and LITE-2, 

demonstrating all of the 

capabilities needed for the TSAT

mission. 

2000s Airborne Lasercom Experiment 

(ALEX) 

ALEX, built by Lincoln Laboratory, successfully 

demonstrated the capabilities necessary for airspace lasercom. 

While ALEX focused on the 

airborne terminal, it demonstrated 

an understanding of the channel 

that is relevant to TSAT lasercom 

AISR support. 

2000s Airborne Laser (ABL) program The ABL program has performed numerous

experiments characterizing the propagation of 

optical wavefronts through various airborne 

environments. These data are relevant to the 

TSAT Air-Space link. 

Atmospheric and airborne

platform boundary 

characterizations. 

Source: MIT Lincoln Laboratory. 

Page 26 GAO-06-537 Transformational Satellite Communications System
Appendix VI: Technology Readiness Levels 

Technology Readiness Level Description Hardware/Software

Demonstration 

Environment 

1. Basic principles observed and 

reported. 

Lowest level of technology readiness. 

Scientific research begins to be translated

into applied research and development. 

Examples might include paper studies of a 

technology’s basic properties.

None (Paper studies and 

analysis) 

None 

2. Technology concept and/or

application formulated. 

Invention begins. Once basic principles are 

observed, practical applications can be 

invented. The application is speculative 

and there is no proof or detailed analysis to 

support the assumption. Examples are still 

limited to paper studies. 

None (Paper studies and 

analysis) 

None 

3. Analytical and experimental

critical function and/ or 

characteristic proof of concept. 

Active research and development is 

initiated. This includes analytical studies 

and laboratory studies to physically 

validate analytical predictions of separate 

elements of the technology. Examples 

include components that are not yet 

integrated or representative. 

Analytical studies and 

demonstration of nonscale 

individual components 

(pieces of subsystem). 

Lab 

4. Component and/ or breadboard. 

Validation in laboratory 

environment. 

Basic technological components are 

integrated to establish that the pieces will 

work together. This is relatively “low 

fidelity” compared to the eventual system. 

Examples include integration of “ad hoc” 

hardware in a laboratory. 

Low fidelity breadboard. 

Integration of nonscale

components to show pieces 

will work together. Not fully 

functional or form or fit but 

representative of technically 

feasible approach suitable for

flight articles. 

Lab 

5. Component and/ or breadboard 

validation in relevant environment. 

Fidelity of breadboard technology 

increases significantly. The basic 

Technological components are integrated 

with reasonably realistic supporting 

elements so that the technology can be 

tested in a simulated environment. 

Examples include “high fidelity” laboratory 

integration of components. 

High fidelity breadboard. 

Functionally equivalent but 

not necessarily form and/or fit 

(size weight, materials, etc.). 

Should be approaching 

appropriate scale. May 

include integration of several 

components with reasonably 

realistic support elements/ 

subsystems to demonstrate 

functionality. 

Lab demonstrating 

functionality but not 

form and fit. May 

include flight 

demonstrating 

breadboard in 

surrogate aircraft. 

Technology ready 

for detailed design 

studies. 

6. System/ subsystem model or 

prototype demonstration in a 

relevant environment. 

Representative model or prototype system, 

which is well beyond the breadboard tested 

for TRL 5, is tested in a relevant 

environment. Represents a major step up

in a technology’s demonstrated readiness. 

Examples include testing a prototype in a 

high fidelity laboratory environment or in 

simulated operational 

environment. 

Prototype—Should be very 

close to form, fit and function. 

Probably includes the 

integration of many new 

components and 

realistic supporting 

elements/subsystems if 

needed to demonstrate full 

functionality of the 

subsystem. 

High-fidelity lab 

demonstration or 

limited/ restricted 

flight 

demonstration for a 

relevant 

environment. 

Integration of 

technology is 

well defined. 

Appendix VI: Technology Readiness Levels 

Page 27 GAO-06-537 Transformational Satellite Communications System
Appendix VI: Technology Readiness Levels 

Technology Readiness Level Description Hardware/Software

Demonstration 

Environment 

7. System prototype demonstration 

in an operational environment. 

Prototype near or at planned operational 

system. Represents a major step up from 

TRL 6, requiring the demonstration of an 

actual system prototype in an operational 

environment, such as in an aircraft, vehicle 

or space. Examples include testing the 

prototype in a test bed aircraft. 

Prototype. Should be form, fit 

and function integrated with 

other key supporting 

elements/ subsystems to 

demonstrate full functionality 

of subsystem. 

Flight 

demonstration in 

representative 

operational 

environment such 

as flying test bed or 

demonstrator 

aircraft. Technology 

is well 

substantiated with 

test data. 

8. Actual system completed and 

“flight qualified” through test and 

demonstration.

Technology has been proven to work in its 

final form and under expected conditions. 

In almost all cases, this TRL represents the 

end of true system development. Examples 

include developmental test and evaluation 

of the system in its intended weapon 

system to determine if it meets design 

specifications.

Flight qualified hardware DT&E in the actual 

system application 

9. Actual system “flight proven” 

through successful mission 

operations. 

Actual application of the technology in its 

final form and under mission conditions, 

such as those encountered in operational 

test and evaluation. In almost all cases, 

this is the end of the last “bug fixing” 

aspects of true system development. 

Examples include using the system under 

operational mission conditions. 

Actual system in final form OT&E in 

operational mission 

conditions 

Source: GAO and its analysis of National Aeronautics and Space Administration data. 

(120478) Page 28 GAO-06-537 Transformational Satellite Communications System
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