Defense Acquisitions: DOD Efforts to Develop Laser Weapons for Theater
Defense (Chapter Report, 03/31/1999, GAO/NSIAD-99-50).

The Pentagon is developing two laser weapons--the Airborne Laser and the
Space-Based Laser--which it intends to use to destroy enemy ballistic
missiles. In a joint effort with Israel, the Defense Department is also
developing a ground-based laser weapon, the Tactical High Energy Laser,
which Israel plans to use to defend its northern cities against
short-range rockets. The three laser weapon programs are in varying
stages of development, ranging from conceptual design studies to
integration and testing of system components. Laser experts agree that
all three programs face significant technical challenges. The Airborne
Laser Program has addressed some technical challenges, such as
completing the collection of non-optical atmospheric turbulence data
from the Korean and Middle East theaters. However, although the Air
Force argues that the design specification established for atmospheric
turbulence is generally accurate, DOD has yet to reach a final position
on this issue. The technical complexity of the Airborne Laser Program
has caused some laser experts to conclude that the laser's planned
flight test schedule is compressed and too dependent on the assumption
that tests will be successful and therefore does not allow enough time
or resources to cope with potential test failures. GAO believes that the
Air Force should reconsider its plan to order a second Airborne Laser
Program aircraft before flight tests show that the system can shoot down
enemy ballistic missiles. Management of the Space-Based Laser Program
has characterized the program's demonstrators as the most complex
spacecraft that the United States has ever attempted to build. If DOD
ultimately decides to continue the program, the size and weight
limitations dictated by current and future launch capabilities will
force the program to push the state of the art in such areas as laser
efficiency, laser power, and deployable optics. The Tactical High Energy
Laser's components have been produced, but initial testing of the laser
has found problems with the operation of the chemical flow control
valves and with the low-power laser to be used in tracking the
short-range rockets the system is designed to shoot down.

--------------------------- Indexing Terms -----------------------------

 REPORTNUM:  NSIAD-99-50
     TITLE:  Defense Acquisitions: DOD Efforts to Develop Laser Weapons
	     for Theater Defense
      DATE:  03/31/1999
   SUBJECT:  Air defense systems
	     Defense capabilities
	     Military aircraft
	     Weapons research and development
	     Ballistic missiles
	     Life cycle costs
	     Schedule slippages
	     Weapons systems
	     Operational testing
	     Military procurement
IDENTIFIER:  DOD Theater Missile Defense Program
	     Patriot Missile Advanced Capability-Three Upgrade
	     Navy Area Defense Program
	     Medium Extended-Range Air Defense System
	     SDI Theater High Altitude Area Defense System
	     DOD Airborne Laser Program
	     DOD Space-Based Laser Program
	     DOD High Energy Laser Technology Program
	     DOD Advanced Concept Technology Demonstration Program
	     Boeing 747-400 Aircraft
	     Israel

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GAO/NSIAD-99-50

GAO United States General Accounting Office

Report to Congressional Requesters

March 1999 DEFENSE ACQUISITIONS

DOD Efforts to Develop Laser Weapons for Theater Defense

GAO/NSIAD-99-50

  GAO/NSIAD-99-50

GAO United States General Accounting Office

Washington, D. C. 20548 Lett er National Security and
International Affairs Division Lett er

B-279125 Letter March 31, 1999 The Honorable Owen B. Pickett
Ranking Minority Member Subcommittee on Military Research and
Development Committee on Armed Services House of Representatives

The Honorable John M. Spratt, Jr. Ranking Minority Member
Committee on the Budget House of Representatives

This report responds to your request that we conduct a review of
Department of Defense (DOD) programs to develop laser weapons for
missile defense. Specifically, you asked us to (1) identify what
laser weapons are being considered for missile defense and the
coordination

among the program offices developing the systems, (2) determine
the current status and cost of each system, and (3) identify the
technical challenges each system faces as determined by DOD
program managers and analysts and other laser system experts. The
report recommends that the Secretary of Defense direct the
Secretary of the Air Force to reconsider plans to exercise the
option for the second ABL aircraft for the engineering and
manufacturing development phase of the Airborne Laser program
before flight testing of the Airborne Laser system developed
during the program definition and risk reduction phase has
demonstrated that the Airborne Laser concept is an achievable,
effective combat system.

We are sending copies of this report to Senator Pete V. Domenici,
Senator Daniel K. Inouye, Senator Carl Levin, ''Senator Frank R.
Lautenberg, Senator Joseph I. Lieberman, Senator Rick Santorum,
Senator Ted Stevens, Senator John W. Warner, Representative Duncan
L. Hunter, Representative John R. Kasich, Representative Jerry
Lewis, Representative John P. Murtha, Representative David R.
Obey, Representative Norman Sisisky, Representative Ike Skelton,
Representative Floyd D. Spence, Representative Curt Weldon, and
Representative C. W. Bill Young in their capacities as Chair or
Ranking Minority Member of Senate and House Committees and
Subcommittees. We are also sending copies of this report to the
Honorable William Cohen, Secretary of Defense; the Honorable F.
Whitten Peters, Acting Secretary of the

Air Force; the Honorable Louis Caldera, Secretary of the Army; the
Honorable Jacob Lew, Director, Office of Management and Budget;
and Lieutenant General Lester L. Lyles, Director, Ballistic
Missile Defense Organization. Copies will also be made available
to others on request.

B-279125 Page 2 GAO/NSIAD-99-50 Defense Acquisitions

Please contact me at (202) 512- 4841 if you or your staff have any
questions concerning this report. Major contributors to this
report are listed in appendix II.

Louis J. Rodrigues Director, Defense Acquisitions Issues

Page 3 GAO/NSIAD-99-50 Defense Acquisitions

Executive Summary Purpose The Ranking Minority Member, House
Committee on the Budget, and the

Ranking Minority Member, Subcommittee on Military Research and
Development, House Committee on Armed Services, asked GAO to
review the Department of Defense's (DOD) programs to develop laser
weapons for missile defense to (1) identify the laser weapons
being considered for missile defense and the coordination among
the program offices

developing the systems, (2) determine the current status and cost
of each system, and (3) identify the technical challenges each
system faces as determined by DOD program managers and analysts
and other laser system experts.

Background DOD is developing a variety of weapon systems as part
of its Theater Missile Defense program. The first generation of
these weapons uses interceptor missiles to intercept and destroy
enemy missiles in the latter stages of their flight. Included
among these systems are the Patriot Advanced Capability- 3, an
improved version of the Patriot system that was used during the
Gulf War; Navy Area Defense; Medium Extended Air

Defense System; Theater High Altitude Air Defense; and Navy
Theater Wide system.

In addition, DOD is developing ballistic missile defense systems
that will use laser beams to destroy enemy missiles. These
systems, as well as a system that is to be used to destroy short-
range artillery rockets, are the focus of this report. Results in
Brief DOD is developing two laser weapons-- the Airborne Laser
(ABL) and the

Space- Based Laser (SBL)-- which U. S. forces intend to use to
destroy enemy ballistic missiles. Additionally, in a joint effort
with Israel, DOD is developing a ground- based laser weapon, the
Tactical High Energy Laser

(THEL), which Israel will use to defend its northern cities
against short- range rockets. ABL is funded and managed by the Air
Force, SBL is jointly funded by the Ballistic Missile Defense
Organization and the Air Force and managed by the Air Force, and
THEL is funded jointly with Israel and managed by the Army. The
respective program offices are coordinating the development of
these programs through various means of information sharing. ABL,
SBL, and THEL are in varying stages of development ranging from
conceptual design studies to integration and testing of system
components.

Executive Summary Page 4 GAO/NSIAD-99-50 Defense Acquisitions

 The ABL program is in the program definition and risk reduction
(PDRR) acquisition phase 1 and is scheduled for full operational
capability in 2009, with a total of seven ABLs. This schedule
reflects a 1- year delay from the original schedule. The Air Force
attributes this slippage to a congressional funding cut and to an
expanded test

program. The Air Force estimates the life- cycle cost of the ABL
to be about $11 billion.  The SBL program is about a year into a
$30- million study phase to define

concepts for the design, development, and deployment of a proof of
concept demonstrator. DOD estimates that it will cost about $3
billion to develop and deploy the demonstrator. The future of the
SBL program is unknown at this time, pending the outcome of a DOD
assessment of the program.

 The $131.5- million THEL Advanced Concept Technology
Demonstration program is about 34 months into a 38- month program.
System components have been built, but system testing has been
delayed from December 1998 to July 1999 due to administrative and
technical

problems. The United States is contributing $106.8 million toward
the program cost and Israel is contributing $24.7 million.

Laser experts agree that the ABL, SBL, and THEL face significant
technical challenges. The ABL program has made progress in
addressing some technical challenges, such as completing the
collection of non- optical atmospheric turbulence data from the
Korean and Middle East theaters. However, in commenting on a draft
of this report, DOD officials stated that while the Air Force's
analyses of these data argue that the design specification
established for atmospheric turbulence is generally accurate, DOD
has yet to reach a final position on this issue. The technical
complexity of the ABL program has caused some laser experts to
conclude that the ABL planned flight test schedule is compressed
and too dependent on the assumption that tests will be successful
and therefore does not allow enough time and resources to deal
with potential test failures and to

prove the ABL concept. GAO believes that the Air Force should
reconsider its plan to order a second ABL aircraft before flight
tests demonstrate that the ABL system can shoot down enemy
ballistic missiles. 1 This phase consists of steps necessary to
verify preliminary design and engineering, build prototypes,
accomplish necessary planning, and fully analyze trade- off
proposals. The objective is to validate the choice of alternatives
and to provide the basis for determining whether to proceed into
the next phase (engineering and manufacturing development) of the
acquisition process.

Executive Summary Page 5 GAO/NSIAD-99-50 Defense Acquisitions

SBL program management has characterized the SBL demonstrator as
the most complex spacecraft the United States has ever attempted
to build. If DOD ultimately decides to continue the program, the
size and weight limitations dictated by current and future launch
capabilities will force the

program to push the state of the art in areas such as laser
efficiency, laser power, and deployable optics.

THEL's components have been produced. However, initial testing of
the laser has identified problems with the operation of the
chemical flow control valves and with the low- power laser that is
to be used in tracking short- range rockets the system is being
designed to defeat.

Principal Findings DOD Developing Three Defensive Laser Weapons

The ABL is expected to be DOD's first system to intercept and
destroy enemy missiles in their boost phase several hundred
kilometers away. The program involves placing multimegawatt
lasers, beam control systems, and related equipment, in a fleet of
seven Boeing 747- 400 freighter aircraft.

The SBL is to be DOD's first space- based laser weapon and is
designed to provide a continuous global boost phase intercept
capability for both theater and national missile defense. Proposed
concepts call for placing multimegawatt chemical lasers, beam
control systems, and related components on a constellation of 20
to 35 satellites. Each SBL is to be capable of destroying about
100 missiles and is to have a range of about 4,300 kilometers.

The THEL is a ground- based weapon that is being designed to
destroy Katyusha 2 and other short- range rockets. It is to detect
an incoming rocket, track the rocket's path, and hold a
concentrated laser beam on the rocket's warhead until the beam's
heat causes the warhead to detonate, destroying the rocket. THEL
is not designed to be powerful and mobile enough to meet U. S.
needs.

2 According to THEL program officials, the Katyusha rocket has a
range of 8 to 24 kilometers, with a flight time of 20 to 80
seconds. Its boost phase is about 1.5 seconds.

Executive Summary Page 6 GAO/NSIAD-99-50 Defense Acquisitions

Coordination Among the Programs

The directors for the three laser development programs are
coordinating their efforts by meeting periodically to share
information on technology and development issues. In addition,
some of the same contractors and contractor personnel are involved
in all three programs, thereby increasing program coordination.
Further, all three programs have benefited from

work performed by the Air Force Research Laboratory. Status and
Cost of the Laser Weapon Programs

The ABL program is currently in the PDRR acquisition phase. In
November 1996, the Air Force awarded the PDRR contract to the team
of Boeing, TRW, and Lockheed Martin. Under this contract, Boeing
is to produce and modify a 747- 400 freighter aircraft and
integrate the laser and beam control system with the aircraft; TRW
is to develop the chemical oxygen iodine laser and ground support
systems; and Lockheed Martin is to develop the beam control
system. One prototype ABL is to be produced and used in 2003 in
attempts to shoot down missiles in their boost phase. This

schedule reflects a 1- year slip in the original PDRR schedule.
According to the program office, this slip is due to a $25-
million reduction made by Congress in the fiscal year 1999
appropriation for the ABL and to an expanded test program. If the
2003 demonstration is successful, the program is to move into the
engineering and manufacturing development phase. The Air Force
estimates the life- cycle cost of the ABL to be about $11 billion,
including $1. 6 billion for the PDRR phase, $1.1 billion for the

engineering and manufacturing development (EMD) phase, $3.6
billion for the production phase, and $4. 6 billion for 20 years
of operations and support.

The SBL program office awarded two 6- month, $10 million contracts
in February 1998 to Lockheed Martin and TRW to obtain information
needed to develop an acquisition plan. It planned to award another
contract in August 1998 for the design, development, and
deployment of the demonstrator. However, that contract was not
awarded because, in August 1998, the Under Secretary of Defense
for Acquisition and Technology directed the Air Force to
restructure the SBL strategy, including considering other
alternatives to the SBL. The Air Force's restructured strategy
shows that a demonstrator would not be launched until the 2010 to
2012 time frame, due to the immaturity of the required technology
and the

projected program funding. The restructured strategy has not
received final approval and is not consistent with Congress'
desire to launch the SBL readiness demonstrator in the 2006 to
2008 time frame. At the time of GAO's review, Ballistic Missile
Defense Organization (BMDO) officials did

not know when or if the proposed restructured acquisition strategy
will be

Executive Summary Page 7 GAO/NSIAD-99-50 Defense Acquisitions

approved and ultimately submitted to Congress. If the SBL is
ultimately selected to proceed, DOD estimates that a fully
operational system would not be deployed until after 2020. The
$131. 5 million THEL system, which is being developed by TRW and
Israel, is scheduled to be the first of the three systems fielded,
albeit not for U. S. use. The program is about 34 months into a
38- month program. The United States and Israel are contributing
$106.8 million and $24.7 million toward the program cost,
respectively. All system components have been built and are in
varying stages of testing and integration. Testing at White Sands
Missile Range against Katyusha rockets, originally scheduled for

December 1998, is now scheduled for July 1999, due to
administrative issues and technical problems with the laser and
tracking system. Technical Challenges Face Each System

While individual components of the proposed systems have been
tested under laboratory conditions and the program offices have
conducted modeling and computer simulations, none of the systems
has been fully integrated and tested as a complete weapon system.
Until this is accomplished, it is not possible to predict with any
degree of certainty the probability that these laser programs will
evolve into viable defense systems.

The ABL program has made progress in addressing some technical
challenges. However, other challenges remain as do concerns about
some Air Force statements of program successes. Specifically, Air
Force statements that the flight- weighted laser module 3 exceeded
power output requirements are questionable because a major
component of the module

did not meet ABL design specifications. Further, the Air Force
states that it met the beam quality requirement for the laser
module; however, it has not yet measured the quality of an actual
laser beam generated by the module. Instead, during the initial
tests, beam quality was estimated using computer models and
measurements of the chemical flows within the laser. The
complexity of the ABL system indicates that initiating the hot
fire flight testing only 4 months prior to the 2003 theater
ballistic missile shoot down tests is not adequate. In that
regard, the Air Force Scientific Advisory Board stated that, "past
experience with high power laser systems and large beam directors
suggests that new and difficult problems will surface in that
[flight test] phase, and many flights and targets will be needed
to

3 A laser module that is of the size and weight that can be
carried by the ABL aircraft.

Executive Summary Page 8 GAO/NSIAD-99-50 Defense Acquisitions

sort them out." Given these complexities, the Air Force's plan to
order a second ABL aircraft, about 1 year before the weapon system
developed during the PDRR phase, attempts to demonstrate that the
proposed ABL system can shoot down an enemy theater ballistic
missile, should be reconsidered.

The high level of technical challenges facing the SBL program is
exemplified by a statement a senior SBL program official made to
GAO that there was a 50- percent chance of being able to build and
deploy the SBL concept demonstrator by 2008 (one of the then-
current deployment goals). According to this official, the SBL
demonstrator would be the most complex spacecraft the United
States has ever built. The major reasons for this technical
complexity are the weight and size constraints dictated by the
limited payload capabilities of current and future launch
vehicles. These constraints will force the program to push the
state of the art in areas such as laser efficiency, laser power,
and deployable optics.

A 7- month schedule delay in the THEL program illustrates the
technical challenges the program must overcome. Testing against
Katyusha rockets at White Sands Missile Range, New Mexico, was to
occur in December 1998, but has now slipped until July 1999 due to
administrative issues associated with contract initiation and
technical problems with the laser

and tracking system. The initial tests of the laser revealed leaks
in the specialized valves that control the flow of chemicals
through the laser. These leaks must be corrected because they
would detract from the performance of the laser. In addition,
testing of the pointer tracker system

disclosed a problem with the low- power laser that is to be used
in tracking incoming short- range rockets.

Recommendation Regarding the ABL program, GAO recommends that the
Secretary of Defense direct the Secretary of the Air Force to
reconsider exercising the

option for the second ABL aircraft for the EMD phase of the
program until flight testing of the ABL system developed during
the PDRR phase has demonstrated that the ABL concept is an
achievable, effective combat system.

Agency Comments and GAO's Evaluation

In a draft of this report, GAO recommended that the Secretary of
Defense direct the Secretary of the Air Force to provide DOD an
assessment of the need to expand the ABL flight test program. In
commenting on that draft

Executive Summary Page 9 GAO/NSIAD-99-50 Defense Acquisitions

report, DOD partially concurred with GAO's recommendation and
stated that its ongoing assessment of the ABL program by an
Independent Assessment Team (IAT) would constitute an appropriate
assessment of the flight test program. 4 Subsequent to DOD's
comments on GAO's draft report, DOD completed its assessment of
the ABL program and reported the results to Congress in March
1999. In its report, DOD noted the IAT's agreement with Air Force
plans to restructure the ABL program to expand testing and risk
reduction activities before starting modifications to the PDRR
aircraft (the first aircraft). DOD concurred with the IAT's
recommendation for more testing of the PDRR aircraft before
Milestone II, which governs entry into engineering and
manufacturing development. DOD stated that it will review the Air
Force's proposed restructured program and set a new

Acquisition Program Baseline in the spring of 1999. During the
restructuring and rebaselining effort, DOD stated that, among
other things, it will revise the exit criteria for Milestone II to
require more testing against threat- representative targets. DOD
stated that it expects that adding flight tests to the program
before the start of EMD will increase near- term costs and might
delay ABL's achievement of an initial operational capability.
However, according to

DOD, the added tests will ensure that the expenditures required
for ABL's EMD phase are justified. GAO agrees with DOD's
assessment and future plans for the ABL program. Therefore, GAO
deleted from its final report the recommendation for an assessment
of the ABL flight test program.

Based on DOD's comments on GAO's draft report that DOD would not
necessarily incur unnecessary costs by proceeding with the
purchase of a second ABL aircraft, GAO revised its recommendation
to reflect the need for DOD to reconsider its planned purchase in
light of the IAT's findings and GAO's report.

GAO recognizes that delaying the procurement of the aircraft for
the EMD portion of the program until after the ABL demonstrates it
can shoot down target missiles might require a change in the
scheduled initial operational

4 This assessment was required by the Strom Thurmond National
Defense Authorization Act for Fiscal Year 1999.

Executive Summary Page 10 GAO/NSIAD-99-50 Defense Acquisitions

capability. However, such a slip would ensure that the procurement
of the EMD aircraft would then be based on the additional
knowledge gained in the shoot down demonstrations that the ABL
design is feasible. GAO's approach is consistent with DOD's March
1999 report to Congress on the ABL program wherein it accepted a
potential delay in the ABL's initial operational capability in
favor of obtaining additional data through

increased flight tests. GAO's approach is also appropriate in view
of the discussion in DOD's March 1999 report on the impact of
turbulence on the ABL design specification. DOD stated that
optical turbulence in excess of the design specification along the
slant path between the ABL and its target

can reduce ABL's maximum lethal range and increase required dwell
times, even at lesser ranges. It said that some analyses of
atmospheric turbulence data collected in theaters of interest to
date suggest that turbulence levels

well above assumed ABL design levels might occur more often than
expected at the time the design levels were set. According to DOD,
there are currently no clear methods for predicting the actual
turbulence level along a slant path to a particular threat
location at a given point in time. Thus, according to DOD, beyond
trial and error, it is not clear how a correct

decision can be made on whether a particular target can be
successfully engaged when launched near ABL's maximum lethal
range. The Air Force is analyzing turbulence data and
investigating tactical decision aids for the system to address
this issue.

DOD's comments are reprinted in appendix I. DOD also provided
separate technical comments that we have incorporated in this
report where appropriate.

Executive Summary Page 11 GAO/NSIAD-99-50 Defense Acquisitions

Page 12 GAO/NSIAD-99-50 Defense Acquisitions

Contents Executive Summary 3 Chapter 1 Introduction

14 Objectives, Scope, and Methodology 16

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in

Various Ways 17

Developing Three Defensive Laser Weapons 17 Coordination and
Technology Sharing 21

Chapter 3 Airborne Laser: Status, Cost, and Technical

Challenges 23

Status and Cost of the ABL Program 23 ABL Program Progress 24
Technical Challenges Remain 25 Planned Ordering of the EMD
Aircraft

May Be Premature 29 Conclusions 29 Recommendation 30 Agency
Comments and Our Evaluation 30

Chapter 4 Space- Based Laser: Status, Cost, and

Technical Challenges 32

Status, Cost, and Technical Challenges 32 Conclusions 34

Chapter 5 Tactical High Energy Laser: Status, Cost, and Technical
Challenges

35 Status and Cost of the THEL Program 35 Conclusions 37

Contents Page 13 GAO/NSIAD-99-50 Defense Acquisitions

Appendixes Appendix I: Comments From the Department of Defense 40
Appendix II: Major Contributors to This Report 44

Tables Table 1. 1: Examples of DOD Laser Development Efforts 14
Figures Figure 2.1: ABL Missile Engagement 18

Figure 2.2: Notional SBL Missile Engagement 19 Figure 2.3: THEL
Rocket Engagement 21

Abbreviations

ABL Airborne Laser AFRL Air Force Research Laboratory ATP
Authority to Proceed BMDO Ballistic Missile Defense Organization
DOD Department of Defense EMD engineering and manufacturing
development HELSTF High- Energy Laser Systems Test Facility PDRR
program definition and risk reduction SBL Space- Based Laser SBLRD
Space- Based Laser Readiness Demonstrator SMDC Space and Missile
Defense Command THEL Tactical High- Energy Laser

Page 14 GAO/NSIAD-99-50 Defense Acquisitions

Chapter 1 Introduction Chapt er 1

The Department of Defense (DOD) and Congress have become
increasingly concerned that U. S. and allied troops abroad may be
attacked by chemical, biological, or nuclear weapons delivered by
ballistic missiles. Operation Desert Storm demonstrated that the
U. S. military and other allied forces have limited capability
against theater ballistic missiles. In fact, U. S. defensive
capability is limited to weapons that defend against missiles
nearing the end of their flight, such as the Patriot. 1
Consequently, developing weapon systems to defeat these threats is
DOD's top priority in its overall ballistic missile defense
program.

DOD has been working with laser technology for a long time. The
following table shows some of the laser development efforts that
DOD has undertaken. To date, none of these efforts has resulted in
an operational laser weapon system.

Table 1. 1: Examples of DOD Laser Development Efforts

1 The Patriot system was initially deployed in 1985 as an anti-
aircraft weapon and modified in the late 1980s to defend against
ballistic missiles as well. It has a range of about 40 miles.

Development effort Purpose Inception date

Tri- Service Laser Program Develop carbon dioxide gas dynamic
laser 1968 Navy- Advanced Research Projects Agency Chemical Laser
Program

Develop high- energy chemical laser 1971 Airborne Laser Laboratory
Demonstrate the feasibility of using a high- energy laser

in an airborne environment 1972 Mid- Infrared Advanced Chemical
Laser Develop and integrate a

ground- based high- energy chemical laser with a beam control
system 1977 Space- Based Laser Program Develop space- based
highenergy chemical laser

weapon system 1977 Ground- Based Laser (free electron) Develop
high- energy free electron laser weapon

system 1979 Ground- Based Laser (Excimer) Develop high- energy
excimer laser weapon system 1979

Chapter 1 Introduction

Page 15 GAO/NSIAD-99-50 Defense Acquisitions

Currently, DOD is developing a variety of weapon systems as part
of its Theater Missile Defense program to counter the potential
threats posed by ballistic missiles. The first generation of these
weapon systems uses interceptor missiles to intercept and destroy
enemy missiles in the latter stages of the missiles' flight.
Included among these systems are the Patriot

Advanced Capability- 3, an improved version of the Patriot system
that was used during the Gulf War; Navy Area Defense; Medium
Extended Air Defense System; Theater High Altitude Air Defense;
and Navy Theater Wide.

In addition, DOD is developing ballistic missile defense systems
that will use laser beams to destroy enemy missiles. DOD plans to
spend billions of dollars to develop these laser weapons and place
them in the air (Airborne Laser) 2 and in space (Space- Based
Laser). In addition, DOD is developing a ground- based laser
(Tactical High- Energy Laser) that is to be used to destroy short-
range artillery rockets.

Congress has generally endorsed DOD's efforts to develop and
produce these laser weapon systems. Its desire to have these
systems developed, produced, and deployed as soon as possible was
heightened by a July 1998 report by the Commission to Assess the
Ballistic Missile Threat to the United States. 3 The Commission
concluded, among other things, that concerted efforts by a number
of overtly or potentially hostile nations to acquire ballistic
missiles with biological or nuclear warheads pose a

growing threat to the United States, its deployed forces, and its
friends and allies.

While endorsing, and in some instances suggesting that DOD's
efforts to develop laser weapon systems to defeat ballistic
missiles be accelerated, Congress has also expressed concern over
the cost and risk associated with developing and demonstrating the
maturity of the technologies required to develop such missile
defense capabilities.

2 See Theater Missile Defense: Significant Technical Challenges
Face the Airborne Laser Program (GAO/NSIAD-98-37, Oct. 23, 1997)
for a discussion of this program. 3 The Commission was established
pursuant to P. L. 104- 201, the National Defense Authorization Act
for Fiscal Year 1997.

Chapter 1 Introduction

Page 16 GAO/NSIAD-99-50 Defense Acquisitions

Objectives, Scope, and Methodology

The Ranking Minority Member, Committee on the Budget, and the
Ranking Minority Member, Subcommittee on Military Research and
Development, Committee on Armed Services, House of
Representatives, asked us to

review DOD's programs to develop laser weapons for missile defense
to  identify what laser weapons are being considered for missile
defense

and the coordination among the program offices developing the
systems,  determine the current status and cost of each system,
and  identify the technical challenges each system faces as
determined by

DOD program managers and analysts and other laser system experts.
To identify the laser weapons being considered for missile defense
and what coordination exists among the programs developing the
systems, we reviewed DOD budget and Airborne Laser (ABL), Space-
Based Laser (SBL), and Tactical High- Energy Laser (THEL) program
office documents. We also met with officials of the Office of the
Secretary of Defense; the

Ballistic Missile Defense Organization, the ABL program office;
the Air Force Space and Missile Systems Center; and the Army Space
and Missile Defense Command. To determine the current status and
cost of each system, we reviewed and analyzed DOD; Air Force;
Army; ABL, SBL, and THEL program offices; and contractor documents
regarding the status and cost of the DOD laser weapon programs. We
discussed the laser programs with officials of the Ballistic
Missile Defense Organization; the ABL program office; the Air
Force Space and Missile Systems Center; the Army Space and Missile

Defense Command; TRW, Inc.; and Lockheed Martin Corporation. To
determine the technical challenges each system faces, we reviewed
and analyzed documents and studies from DOD; Air Force; Army; ABL,
SBL, and THEL program offices; and contractors. We discussed the
technical aspects of the laser programs with officials of the
Office of the Secretary of Defense (Operational Test and
Evaluation); the Ballistic Missile Defense

Organization; the Air Force Air Combat Command; the Air Force
Operational Test and Evaluation Center; the ABL program office;
the Air Force Scientific Advisory Board; the Air Force Space and
Missile Systems Center; the Army Space and Missile Defense
Command; TRW, Inc.; Lockheed Martin Corporation; and Lawrence
Livermore National Laboratory.

Chapter 1 Introduction

Page 17 GAO/NSIAD-99-50 Defense Acquisitions

We conducted our review from November 1997 to December 1998 in
accordance with generally accepted government auditing standards.

Page 17 GAO/NSIAD-99-50 Defense Acquistions

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in Various Ways Chapt er 2

DOD is developing two laser weapons, ABL and SBL, that are to be
used by U. S. forces to destroy enemy ballistic missiles.
Additionally, in a joint effort with Israel, DOD is developing the
THEL, which is to be used by Israel to

defend against short- range rockets. All three programs have
benefited from work performed by the Air Force Research Laboratory
on lasers and associated systems. In addition, the program
directors for these three programs are coordinating their efforts
by meeting periodically to discuss and share information on
technology

and program development issues. Moreover, some of the same
contractors and contractor personnel are involved in all three
programs, thereby increasing program coordination.

Developing Three Defensive Laser Weapons

The ABL is to be carried by a 747 aircraft, and the SBL by a
constellation of satellites. Both of these weapons are to be used
by U. S. forces to destroy ballistic missiles while the missiles
are still in the early stage of their flight (boost phase). The
THEL is a ground- based laser weapon Israel is to use to defend
its northern border cities against Russian- made Katyusha rocket 1
attacks in the final stages of the rockets' flight.

ABL Program The ABL, funded and managed by the Air Force, is
planned to be the first system with the ability to detect and
destroy enemy missiles in their boost phase several hundred
kilometers away. It is a complex laser weapon system that is being
designed to detect an enemy missile shortly after its launch,
track the missile's path, and hold a concentrated laser beam on
the missile until the beam's heat causes the pressurized missile
casing to crack,

in turn causing the missile to explode and the warhead to fall to
earth well short of its intended target. The program involves
placing a multimegawatt laser, beam control system, and related
equipment in a Boeing 747- 400 freighter aircraft. One prototype
ABL is to be produced and tested in 2003 in attempts to shoot down
missiles in their boost phase. If this demonstration is
successful, the program is scheduled to move into the

engineering and manufacturing development phase in 2004. Figure
2.1 shows the ABL concept.

1 According to THEL program officials, the Katyusha rocket has a
range of 8 to 24 kilometers, with a flight time of 20 to 80
seconds. Its boost phase is about 1.5 seconds.

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in Various Ways

Page 18 GAO/NSIAD-99-50 Defense Acquistions

Figure 2.1: ABL Missile Engagement

The ABL is expected to operate from a central base in the United
States and be available to be deployed worldwide. Ultimately, with
a seven- aircraft fleet, five aircraft are expected to be
available for operational duty at any given time. The other two
aircraft are expected to be undergoing

modifications or undergoing maintenance or repair. When the ABLs
are deployed, two aircraft are to fly in figure- eight patterns
above the clouds at about 40, 000 feet. Through in- flight
refueling and rotation of aircraft, two

ABLs will always be on patrol, thus ensuring 24- hour coverage of
potential 100,000 80,000

60,000 40,000 20,000

0

Cloud Tops Altitude (feet)

Missile destroyed

Laser Dwell Destruction

Tracking Detection Booster burnout

747

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in Various Ways

Page 19 GAO/NSIAD-99-50 Defense Acquistions

missile launch sites within the theater of operations. Each ABL is
to be capable of destroying about 20 missiles before chemicals
needed to generate the laser beam need to be replenished. At that
point, the aircraft will have to land to refuel the laser.

SBL Program The SBL, jointly funded by the Ballistic Missile
Defense Organization (BMDO) and the Air Force and managed by the
Air Force, is to be capable of detecting a missile in its boost
phase, tracking the missile's path, and holding a concentrated
laser beam on the missile until the beam's heat causes the missile
to be destroyed. The SBL program involves integrating a

multimegawatt laser, beam control system, and related equipment on
a space platform and launching it into low earth orbit. Air Force
estimates show that a full SBL system would not be deployed until
after 2020. Figure 2.2 shows a notional SBL engagement.

Figure 2.2: Notional SBL Missile Engagement

DOD is developing the SBL to provide a continuous global boost
phase intercept capability for both theater and national missile
defense. The Booster Destruct Laser Energy On Booster

Identify and Track Target Detect Target

Target

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in Various Ways

Page 20 GAO/NSIAD-99-50 Defense Acquistions

notional concept involves having a constellation of 20 to 35 SBLs.
Each SBL is to be capable of destroying about 100 missiles and is
to have a range of about 4,300 kilometers.

THEL Program The THEL, funded jointly with Israel and managed by
the U. S. Army, is a ground- based laser weapon that is to be used
to destroy short- range rockets toward the end of their flights.
THEL is to accomplish this by detecting an incoming rocket shortly
after it has been launched, tracking the rocket's path, and
holding a concentrated laser beam on the rocket's warhead until
the beam's heat causes the warhead to detonate, destroying

the rocket. The THEL program involves designing and building a
multi- hundred kilowatt chemical laser, a beam control system, a
fuel supply system, a laser exhaust system, and other equipment to
fit into separate, transportable containers, sized so that each
container can be transported by a large truck. The transportable
containers are to be placed on concrete pads at deployment sites.
Once deployed, the THEL components in each separate container are
to be integrated. All THEL components have been produced and are
scheduled to be integrated and tested at White Sands Missile
Range, New Mexico, in July 1999. Figure 2.3 shows the THEL

concept.

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in Various Ways

Page 21 GAO/NSIAD-99-50 Defense Acquistions

Figure 2.3: THEL Rocket Engagement

DOD is developing the THEL, in a joint effort with Israel, to be
used by Israel to defend against Russian- made Katyusha rockets
and other shortrange rockets that have been used by terrorists to
attack cities in northern Israel. The number of rockets THEL is
capable of destroying is limited only by the amount of laser fuel
stored at the deployment site.

Although THEL is a transportable system that can be moved by large
trucks, it is not a mobile system, in the sense that the
integrated system cannot move under its own power. Because of this
limitation, the United States has no use for THEL as it is
currently designed. See chapter 5 for additional discussion of the
U. S. need for a mobile THEL- type system.

Coordination and Technology Sharing The three laser weapon
development programs have coordinated their efforts by holding
periodic program director conferences to share information. In
addition, some of the same contractors and contractor personnel
are involved in all three programs and all three programs have
Detect

Target Track

Target Beam on Target THEL Fire Unit Target Kill

Defended Zone THEL Radar Unit

Chapter 2 DOD Developing Three Laser Weapons and Coordinating Its
Development Efforts in Various Ways

Page 22 GAO/NSIAD-99-50 Defense Acquistions

benefited from work performed by the Air Force Research Laboratory
on lasers and associated systems.

According to the program directors of the ABL, SBL, and THEL, they
have conducted periodic conferences and frequent phone
conversations to discuss and share information on technology and
program development issues. They told us that technology developed
under one program is shared where appropriate by all programs,
thereby reducing duplication. For example, weight reduction
techniques developed under the SBL program are to be used on the
ABL and THEL programs.

TRW is a subcontractor for the ABL and SBL programs and the prime
contractor for the THEL program and is developing the lasers for
all three programs. ABL program officials told us that some of the
same TRW personnel work on all three programs, thus transferring
and sharing their

laser technology knowledge between the programs. In another case,
the same contractor is to produce the deformable mirrors 2 used in
the ABL and SBL programs.

All three programs have benefited from the research carried out by
the Air Force Research Laboratory (AFRL). For example, all
programs plan to use AFRL- developed optical coatings for beam
control and laser optical systems. With these specialized
coatings, optics absorb little energy from a high energy laser
beam, and heavy, vibration- inducing cooling systems are

not needed. AFRL officials have also participated in the three
programs in various ways, which enhances information sharing. For
example, an AFRL official participating in the ABL program is also
acting as a THEL principal on- site government representative.

2 A deformable mirror is a flexible reflective surface mounted to
an array of actuators, or pistons, that can rapidly (up to 1,000
times per second) alter the shape of the mirror. In effect, the
mirror's shape is altered to predistort an outgoing laser beam,
which is then refocused by the turbulence through which the beam
travels on its way to the target.

Page 23 GAO/NSIAD-99-50 Defense Acquisitions

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges
Chapt er 3

The ABL program is currently in the program definition and risk
reduction (PDRR) acquisition phase. 1 Initial operational
capability of three ABLs is scheduled for 2007 and full
operational capability of seven ABLs is

scheduled for 2009. This schedule reflects a program slip of about
1 year. The Air Force estimates the life- cycle cost of the ABL at
about $11 billion.

The ABL program has made progress in addressing some technical
challenges, such as atmospheric turbulence that we and others have
reported on in the past. However, challenges remain because the
components of the system are in various stages of development and
have yet to be produced in their final configurations, tested, and
integrated into an operational weapon system. Because of the
complexity of this integration, some laser experts both inside and
outside of DOD have noted that the planned flight testing schedule
for the program should be

expanded. We believe that the technical complexity of the ABL and
related integration issues also raises questions about whether the
Air Force's planned ordering of a second aircraft, for
modification during the engineering and manufacturing development
(EMD) phase of the program, is premature.

Status and Cost of the ABL Program In November 1996, the Air Force
awarded a 77- month PDRR contract to the contractor team of
Boeing, TRW, and Lockheed Martin. Under the

contract, Boeing is to produce and modify a 747- 400 freighter
aircraft and integrate the laser and beam control system with the
aircraft; TRW is to develop the laser and ground support systems;
and Lockheed Martin is to develop the beam control system. The
PDRR phase includes two interim

milestones-- Authority to Proceed 1 (ATP- 1), originally scheduled
for June 1998, and ATP- 2, scheduled for August 2002. The ABL
passed ATP- 1 in September 1998, 3 months late because the flight-
weighted laser module

had problems producing the required power level. The PDRR phase is
scheduled to culminate with attempts, in 2003, by the PDRR ABL
aircraft to destroy a boosting theater ballistic missile. If these
demonstrations are successful, the program is scheduled to move
into the

engineering and manufacturing development phase in 2004. Initial 1
This phase consists of steps necessary to verify preliminary
design and engineering, build prototypes, accomplish necessary
planning, and fully analyze trade- off proposals. The objective is
to validate the choice of alternatives and to provide the basis
for determining whether to proceed into the next phase
(engineering and manufacturing development) of the acquisition
process.

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges

Page 24 GAO/NSIAD-99-50 Defense Acquisitions

operational capability of three ABLs is scheduled for 2007; full
operational capability of seven ABLs is scheduled for 2009. This
schedule reflects a 1- year slip in the original PDRR schedule.
According to the program office,

the revision to the schedule is due to a $25- million reduction
Congress made in the fiscal year 1999 appropriation for the ABL
and to an expanded test program. The Air Force estimates the life-
cycle cost of the ABL to be about $11 billion, including $1.6
billion for the PDRR phase, $1. 1 billion for the EMD phase, $3.6
billion for the production phase, and $4.6 billion for

20 years of operations and support. ABL Program Progress We
reported on the ABL program in October 1997. At that time, the

immediate area of concern that we and others reported was whether
the program had adequately assessed the adverse effects of
atmospheric turbulence on the ABL's operational effectiveness. 2
We reported that the Air Force did not have all of the data needed
to fully understand the effect

that atmospheric turbulence would have on the operation of the ABL
and that the Air Force had not determined whether non- optical
turbulence measurements could be correlated to optical turbulence
measurements. 3 We reported that the Air Force had not shown that
it could accurately predict the levels of turbulence the ABL will
actually encounter; neither

had it shown that the ABL's technical requirement regarding
turbulence was appropriate. Consequently, we concluded that it was
not yet known whether the ABL would be able to operate effectively
in its operational environment. In addition, we reported that the
Air Force planned to only take additional non- optical turbulence
measurements to predict the

severity of the optical turbulence the ABL would encounter without
first determining whether the two measurement types could be
correlated.

The Air Force has now completed collecting non- optical
atmospheric turbulence data from the Korean and Middle East
theaters. In commenting on a draft of this report, DOD stated
that, while the Air Force's analyses of 2 The type of turbulence
that the ABL will encounter is referred to as optical turbulence.
It is caused by

temperature variations in the atmosphere. These variations distort
and reduce the intensity of the laser beam. Unless these
turbulence effects are compensated for, they decrease the laser
beam's effective range.

3 Optical turbulence measurements are taken by instruments that
directly measure distortions in light that has traveled from a
point source through the atmosphere to the measuring instrument.
This can be accomplished by transmitting laser beams from one
aircraft to instruments on- board another aircraft at various
altitudes and distances, or by focusing on a point source of
light, such as a star. Non- optical turbulence measurements are
taken by radar or by temperature probes mounted on balloons or on
an aircraft's exterior.

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges

Page 25 GAO/NSIAD-99-50 Defense Acquisitions

these data argue that the design specification established for
atmospheric turbulence is generally accurate, the DOD has yet to
reach a final position on this issue. DOD stated further that it
is still examining the design specification for atmospheric
turbulence. According to DOD, the Air Force plans to collect and
characterize additional data to further validate its

design assumptions. DOD also stated that uncertainties remain
concerning the ability to use non- optical turbulence measurements
under all conditions to predict operational performance for the
ABL. It said that it was considering what additional measurements
and analysis are needed to

resolve these uncertainties. The Air Force has also been able to
establish that the correlation between non- optical and optical
data is adequate for the purposes of estimating ABL performance
using non- optical data at this stage of the program. However,
according to DOD officials, there are instances where optical and
nonoptical data disagree and the causes of these differences are
not understood. Consequently, the Air Force is continuing to
collect and analyze data to further validate its turbulence design
assumptions.

Technical Challenges Remain

While the ABL program has made progress in addressing technical
challenges relating to atmospheric turbulence, other challenges
remain. Developing a laser module that is of the size and weight
that can be carried by the ABL aircraft (referred to as a flight-
weighted laser module), and

integrating the laser, beam control system, and related equipment
into an aircraft, are two examples of these challenges.

Flight- Weighted Laser Module Challenges

The technical challenge inherent in the ABL program is exemplified
by problems experienced in developing the high- energy laser. The
Air Force must build the laser to be able to contend with size and
weight restrictions, motion and vibrations, and other factors
unique to an aircraft environment, yet be powerful enough to
sustain a killing force over a range of hundreds of kilometers. It
is also to be constructed in a configuration that links

modules together to produce a single high- energy beam. The laser
being developed for the PDRR phase will have six modules. The
laser for the EMD phase will have 14 modules. When we issued our
report on the ABL in 1997, the program had constructed and tested
a developmental laser module. Although that developmental module
exceeded its energy output requirements, it was too heavy and
large to meet integration requirements. It would have to be
reduced in width by about one- third and reduced in weight by over
one- half. To accomplish this, many components of the

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges

Page 26 GAO/NSIAD-99-50 Defense Acquisitions

module would have to be reconfigured and built of advanced
materials, such as composites. As previously discussed, the PDRR
phase of the ABL program includes two milestone decision points--
referred to as ATP- 1 and ATP- 2. To pass ATP- 1, the Air Force
had to "demonstrate a single laser module at full power with all
critical components flight- weighted and show performance (power,

beam quality, chemical efficiency, thermal management) is
scaleable/ traceable to the EMD design through analysis." During
testing of the flight- weighted laser module in connection with
the scheduled June 1998 ATP- 1 decision point, the module failed
to meet its power output requirement. Because of this failure, the
program provisionally passed

ATP- 1. The program fully passed ATP- 1 when, 3 months later, the
laser module exceeded its power output requirement by 10 percent.
However, the power output was achieved using a flight- weighted
laser module that was not representative of the laser modules that
will be used in an operational ABL

weapon system. Specifically, the flight- weighted laser module
used for testing in connection with ATP- 1 used a stable
resonator. ABL design specifications require that an unstable
resonator be used. 4 According to program officials, an unstable
resonator is needed because it would produce a laser beam that
would allow the ABL's beam control system to focus more of the
beam's power on the target than would be possible with a beam
produced by a stable resonator. In commenting on a draft of this
report, DOD stated that a stable, versus unstable, resonator was
used for the initial flight- weighted laser module tests because
the test facility had a

stable resonator in place, and to replace the stable resonator
with an unstable resonator would have been too costly and would
have adversely affected the program schedule.

In addition to demonstrating the laser module at full power, ATP-
1 also required the program to demonstrate that the beam quality
of the laser 4 A resonator consists of two mirrors placed at
opposite ends of a laser cavity. As the reaction of

chemicals within the laser cavity produces photons of light, the
photons are reflected back and forth between the two mirrors,
which causes additional photons to be generated, resulting in a
state of high energy within the cavity. In a stable resonator, one
mirror is fully reflective while the other is only partially
reflective, allowing part of the energy to escape from the laser
cavity in the form of a

high- energy laser beam. In an unstable resonator, both mirrors
are fully reflective but one is much smaller in diameter. As the
photons are reflected from the larger mirror in the direction of
the smaller mirror, energy escapes from the laser cavity by
passing around the edges of the smaller mirror in the form of a
high- energy laser beam.

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges

Page 27 GAO/NSIAD-99-50 Defense Acquisitions

beam generated by the module would meet ABL design requirements.
In meeting this requirement, the Air Force did not measure the
quality of an actual laser beam generated by the module. Instead,
it estimated the beam quality using computer models and
measurements of the chemical flows

within the laser. In future tests of the laser module, the Air
Force plans to measure the beam quality of an actual beam
generated by the laser module.

In attempting to demonstrate the laser module at full power, the
Air Force identified several design problems. For example, the
catch tank and catch tank outlet, which collect and recirculate a
chemical used by the laser, were too small. This limited the flow
rate of the chemical, reducing the

laser's power. Another problem identified was that too much water
vapor entered the laser cavity, which reduced the amount of power
generated. In addition, gas pressure within the laser cavity was
too high, thus slowing the

velocity of gases through the cavity, which also reduced the
amount of power generated. Some modifications were made to achieve
higher power levels during testing. These and other modifications
are currently being finalized and incorporated into the flight-
weighted laser module.

System Integration Challenges The ABL program manager stated that
integrating a weapon- level laser, beam control system, and the
other related components into an aircraft is the largest challenge
facing the program. Some individual components of the ABL have
been tested under laboratory conditions and the program office has
conducted modeling and computer simulations. However, the
individual components have not been integrated and tested as a
complete weapon system. As we stated in our October 1997 report,
until this system

integration and testing is accomplished, it is not possible to
predict with any degree of certainty the probability that the ABL
program will evolve into a viable missile defense system. A major
aspect of this system integration testing will be the hot fire
flight tests when the laser is turned on and the beam is
controlled by the beam control system. According to planning
documents, hot fire flight testing begins only 4 months prior to
the 2003 theater ballistic missile shoot- down tests. Because of
the complexity of the system integration task, some experts both
inside and outside of DOD have noted that the planned flight
testing schedule for the program is too dependent on successful
tests and does not allow enough time and resources to deal with
potential test failures and to prove the ABL concept.

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges

Page 28 GAO/NSIAD-99-50 Defense Acquisitions

In a May 1998 Early Operational Assessment, the Air Force
Operational Test and Evaluation Center characterized the flight
test schedule as "compressed and success- oriented." In addition,
the Air Force Scientific Advisory Board, in its February 1998
report, "Airborne Laser Scenarios and

Concept of Operations," stated that while the ABL program
evolution as currently planned is rational in its sequencing of
tests, the schedule appears to have an unrealistically brief
flight testing phase. The Board

characterized the flight test program as "immature" and said that
it needs to be structured to build high confidence in the
operability of the laser system. It further stated that past
experience with high- power laser systems and large beam directors
suggests that new and difficult problems will surface in that
phase, and that many flights and targets will be needed

to sort them out. The Board suggested that the laser should be
fired a reasonably large number of times (in the hundreds) with
the ABL in flight before committing to a lethality demonstration
and that this would serve to gain experience; establish that it is
safe, reliable, and routine; and measure

the critical parameters that will give a commander the confidence
to use the system without hesitation. Consequently, the Board
advised the Air Force to develop contingency plans to prepare for
the possibility that the current success- oriented schedule is not
achieved, to include ordering additional long lead targets if
required, the identification of potential avenues of failure
during the flight tests, and preparation of work- arounds or
corrective steps prepared in advance.

Congress has also raised concerns related to this issue. The
conference report on the Strom Thurmond National Defense
Authorization Act for Fiscal Year 1999 noted that the conferees
are concerned that the Air Force plans to enter EMD without
adequate time to operate, test, and evaluate the PDRR
configuration. As a result, the conferees directed the Secretary
of Defense to establish an independent review team to assist with
the Secretary's evaluation of the technical risk in the ABL
program and his

determination of whether (1) additional testing and risk reduction
is necessary prior to integration of the ABL subsystems into a
commercial 747- 400F aircraft and (2) the fully integrated PDRR
aircraft should be operated for a period of time and thoroughly
tested prior to finalizing an objective design. The act directed
the Secretary of Defense to report the findings of his assessment
of the ABL program by March 15, 1999.

Chapter 3 Airborne Laser: Status, Cost, and Technical Challenges

Page 29 GAO/NSIAD-99-50 Defense Acquisitions

Planned Ordering of the EMD Aircraft May Be Premature

The technical complexity of the ABL and related integration issues
raise questions about when a second aircraft, for modification
during the EMD phase, should be ordered. Current program plans
call for an aircraft to be ordered about 1 year before the planned
attempts to shoot down a theater

missile with the PDRR aircraft. The Air Force has a contract with
Boeing for the aircraft that will be used during the PDRR phase.
According to ABL acquisition plans, a second 747- 400 freighter
will be ordered in September 2002 for the EMD phase. 5 The
ordering of the aircraft is to immediately follow the August 2002
ATP- 2 meeting. However, this acquisition strategy will result in
the second aircraft being ordered about 1 year prior to the
scheduled demonstration of the ABL's ability to shoot down a
theater ballistic missile. Conclusions The ABL program has made
progress in addressing some technical challenges, such as
atmospheric turbulence, that we and others have reported on in the
past. However, challenges will continue through the development
program and we have concerns about some Air Force

statements of program successes-- specifically, statements related
to the power output and beam quality of the flight- weighted laser
module. Once these and other problems are resolved, the major
program challenge will be

to integrate the individual system components into a complete
weapon system for testing. A major test for the program will be
the flight tests during which the laser is turned on and its beam
is controlled by the beam control system. Independent reviews of
the ABL program by laser experts indicate that the ABL flight test
plan may be too limited and too dependent on successful tests, and
not allow enough time and resources to deal with potential test
failures and to prove the ABL concept.

The technical complexity of the ABL and related integration issues
also raise questions about when a second aircraft, for
modification during the EMD phase of the program, should be
ordered. Current plans call for the

EMD aircraft to be ordered about 1 year before the PDRR aircraft
attempts to shoot down theater ballistic missiles. If the PDRR
aircraft fails to prove the ABL concept, the funds expended for
the EMD aircraft may be wasted. 5 ABL acquisition plans call for a
total of seven aircraft. One ABL is to be produced during the PDRR
phase, a second during the EMD phase, and five more are to be
developed during the production phase. Also, during the production
phase, the aircraft from the PDRR and EMD phases are to be
refurbished to production standards.

*** End of document. ***