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Debunking the Missile Defense Agency’s
‘Endgame Success’ Argument
The Pentagon’s Missile Defense Agency (MDA) has become increasingly
averse to providing detailed reports to Congress or the public on
the progress of U.S. missile defense programs. It has also recently
decided to classify more information about missile defense intercept
tests. Given this reduction in independent oversight, it is especially
important to determine the extent to which information provided
by the MDA is credible and trustworthy. Unfortunately, close examination
of statements by MDA officials, who have been arguing that the test
record for hit-to-kill missile defenses shows that such systems
will work, demonstrates that the Pentagon has been less than forthright
about its successes and failures.
Specifically, Lieutenant General Ronald Kadish, director of MDA,
testified to Congress on June 25 that many missile defense test
failures were due to quality-control problems that prevented the
interceptor from reaching the “endgame”—the difficult
final phase of the intercept attempt that begins when the kill vehicle
is released from its booster and attempts to detect, home in on,
and destroy its target. That is, according to Kadish, many intercepts
fail in their early stages, during the less technologically challenging
phases of the test. Kadish argued that, in tests in which the endgame
is reached, the interceptors actually have a very high success rate
of 88 percent. Moreover, in testimony June 14, 2001, he argued that
this high “endgame success” rate shows that “the
feasibility of missile defense and the availability of technologies
to do this mission should not be in question.”
This argument is wrong for several reasons:
Inaccurate statistics: The numbers Kadish uses are incorrect;
he undercounts the number of endgame failures. Kadish claims that,
of the 25 missile defense tests in which the interceptor reached
the endgame, the target was hit 22 times, for a success rate of
88 percent. This formulation, however, omits six additional endgame
failures by incorrectly assessing them as failures prior to the
endgame. The true endgame success rate is only 71 percent (22
of 31)
Midcourse and terminal defenses inappropriately lumped together:
Kadish essentially mixes apples and oranges by combining test
data for terminal and midcourse missile defenses. Doing so is
inappropriate since these two types of defenses operate quite
differently. All the midcourse systems are designed to operate
above the atmosphere against medium- to long-range missiles (the
Theater High Altitude Area Defense is also capable of operating
in the upper reaches of the atmosphere), and all use a kill vehicle
that is released from a booster rocket, uses infrared sensors
for homing, and maneuvers using divert thrusters. In contrast,
the terminal defenses tested only operate within the atmosphere
against shorter-range missiles. They do not use a kill vehicle
but an interceptor that is a single-stage missile; they use a
radar for homing instead of an infrared sensor; and they maneuver
using atmospheric forces rather than divert thrusters. The endgame
success rate of the midcourse intercepts is only 61 percent (11
of 18).
Endgame success rate is not higher than pre-endgame success
rate: Because a successful intercept requires that all successive
phases of the test be successful, the “partial” success
rate for any one phase of the intercept attempt will be higher than
the overall success rate. For both midcourse and terminal systems,
the endgame success rate is actually slightly lower than the success
rate prior to the endgame. Of the 27 midcourse tests, 18 (67 percent)
successfully reached the endgame. Of these 18, only 11 (61 percent)
actually hit their targets. Thus, on a percentage basis, more tests
failed during the endgame than before.
Endgame success rate is irrelevant: There is no reason
to consider the endgame success rate rather than the overall success
rate because quality control errors can and have occurred in all
phases of the tests. Taking into account failures that occur both
prior to and during the endgame, the overall success rate for midcourse
systems drops to only 41 percent (11 of 27).
Intercept tests do not adequately simulate real world usage:
All of the hit-to-kill tests conducted to date have—as MDA
itself notes—included numerous “limitations” and
“artificialities,” so even a perfect test record would
say little about the ability of the system to perform under realistic
operational conditions. Contrary to Kadish’s June 2001 statement,
the feasibility of missile defense and the availability of needed
technologies remain in question.
Regardless of how they are tabulated, the test results do not
indicate anything meaningful about the technical feasibility of
the missile defense systems under development. The MDA analysis
that Kadish presented to Congress is based on misrepresenting
the results of past tests, and its conclusions are misleading.
This analysis raises serious questions about the recent MDA decision
to classify information about its future intercept tests because
further secrecy will make it nearly impossible for independent
analysts to check MDA’s claims. If Congress and the public
are to have a realistic understanding of the system’s capabilities,
MDA programs must be subject to continuing and increased congressional
and independent oversight.
A Closer Look at the Numbers
During his June 25 testimony, General Kadish explained how MDA
obtained its 88 percent success rate in the endgame. A slide accompanying
his presentation included five categories of system tests, dating
back to the first hit-to-kill missile defense test, conducted
in 1983 under the Strategic Defense Initiative:
(1) Thirteen tests of ground-based midcourse defenses conducted
as of Kadish’s June 25 testimony: the four homing overlay
experiment (HOE) tests and the two exoatmospheric reentry vehicle
interceptor subsystem (ERIS) tests, which were predecessors to
the current ground-based midcourse system; the Delta 180 experiment,
in which two satellites were maneuvered to collide with each other;
and the six ground-based national missile defense system intercept
tests. (Kadish’s figures could not include the October 14
ground-based midcourse test, which was a success.)
(2) Two tests of the sea-based midcourse defense system (formerly
known as Navy Theater Wide) conducted in 2002, using the light-weight
exoatmospheric projectile (LEAP) kill vehicle.
(3) Four exoatmospheric LEAP tests carried out between 1992 and
1995, two ground-based and two sea-based; and the two exoatmospheric
tests of the Theater High Altitude Area Defense (THAAD), a ground-based
system designed to intercept short- and medium-range ballistic
missiles.
(4) Six high-endoatmospheric THAAD tests.
(5) Fourteen tests of the Patriot Advanced Capability-3 (PAC-3)
and its developmental predecessors against ballistic missile targets
in their terminal stage.
Kadish claims that of these 41 tests, 25 reached the endgame
and 22 of those were successes, leading to an 88 percent endgame
success rate. There are two problems with these figures. The first
problem is a minor one: the figures completely omit one failed
PAC-3 test. Thus, while Kadish includes a total of 41 tests, of
which 14 were tests of terminal defenses, the authors’ analysis
includes a total of 42 tests, with 15 tests of terminal defenses.
The second problem is much more significant. In addition to the
one failed midcourse test acknowledged by Kadish to have reached
the endgame, six additional failed tests were endgame failures
but were not counted as such by Kadish:
HOE, first intercept attempt, February 7, 1983: The kill
vehicle’s failure to hit the target was attributed to problems
in the interceptor’s infrared sensor cooling system that
caused the sensor to be warmer than expected and produced noise
saturating the kill vehicle’s flight computer. This endgame
failure is similar in nature to the one midcourse endgame failure
acknowledged by Kadish: the January 18, 2000, national missile
defense test, in which the sensor cooling system also failed.
(In the three subsequent Homing Overlay tests, the sensor’s
detection threshold was raised in order to eliminate the noise,
and the target was also heated.)1
HOE, second intercept attempt, May 28, 1983: Although
the kill vehicle completed the flight sequence required to intercept
the target, the intercept did not occur, Army officials said shortly
after the test.2 The interceptor reportedly
demonstrated successful homing but missed due to a “random”
failure in the guidance electronics.3
HOE, third intercept attempt, December 16, 1983: In this
test, the kill vehicle successfully demonstrated its ability to
home on the target, but a software error in its onboard computer
prevented it from converting homing data into steering commands,
causing the kill vehicle to miss.4
ERIS, second intercept attempt, March 13, 1992: The ERIS
failed to hit the target, which was accompanied by a single balloon
“decoy,” reportedly missing by “several meters.”5
The decoy and target were separated by about 20 meters and the
kill vehicle flew between them.6 The miss
was apparently a result of two factors: a greater than anticipated
separation between the decoy and target and a later than expected
detection (by about 0.2 second) of the target relative to the
decoy. According to the ERIS project manager, mission planners
had allowed 0.8 seconds for the kill vehicle to maneuver, but
at least 0.9 seconds were actually needed.7
This test illustrates that even small deviations from a carefully
scripted intercept test can lead to failure.
LEAP, fourth intercept test, March 28, 1995: The LEAP
failed to hit the target, apparently because a battery failed.8
The intercept proceeded normally up to the point at which the
kill vehicle was ejected from the missile, and the LEAP apparently
saw the target before it was ejected from the missile. The LEAP
had no electrical power after release, however, and missed the
target by 167 meters.9
It could be argued that this is not an endgame failure since
the kill vehicle had no power after release. However, the kill
vehicle was apparently released in the right place for detecting
and intercepting the target, failing to do so because a vital
component of the kill vehicle malfunctioned. In a sense, this
failure is no different than an error by the seeker or a divert
thruster, and the test must therefore be counted as an endgame
failure
THAAD, third intercept attempt (high-endoatmospheric test),
July 15, 1996: Program officials said the kill vehicle came
within “a matter of yards of the target.”10
The failure was reportedly caused by a problem with either the
seeker electronics or a contaminated dewar in the infrared seeker.11
In addition to these six endgame failures, four additional failed
intercepts clearly entered the endgame but failed because either
the target or interceptor was incorrectly positioned (the second
and third LEAP and first THAAD intercept tests) or because the
kill vehicle did not receive expected information about the target
(first LEAP test). We do not count these as having reached the
endgame, however, because the failure to hit the target was caused
by problems not directly associated with the kill vehicle and
its technology. These tests nonetheless provide further examples
of how a deviation from the preplanned “script” of the
test will lead to failure.
|
Systems Tested
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Total Tests
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Reached Endgame
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Hit Target
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|
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Kadish
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Authors
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Kadish
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Authors
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|
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Ground-Based Midcourse
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13
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8
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12
|
7
|
|
Sea-Based Midcourse
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2
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2
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2
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|
LEAP and THAAD (Exo)
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6
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1
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2
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1
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THAAD (High Endo)
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6
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1
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2
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1
|
|
Midcourse Subtotal
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27
|
12
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18
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11
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|
Terminal
|
14
|
15
|
13
|
11
|
|
Total
|
41
|
42
|
25
|
31
|
22
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This table shows the numbers used by Kadish and, where they
differ, the authors’ numbers. Kadish cites 25 total tests
as reaching the endgame, 22 of which hit their target. He therefore
says that missile defense programs have an 88 percent endgame
success rate. In fact, 31 tests reached the endgame, meaning that
the success rate is actually 71 percent. Moreover, analysis of
only the midcourse endgames yields a success rate of only 61 percent,
and the overall success rate for midcourse systems is 41 percent.
(Note that this final figure would be 43 percent after the successful
October 14 test of the ground-based midcourse system.)
NOTES
1. David A. Fulghum, “Army Officials Deny Rigging SDI Test,”
Aviation Week and Space Technology, August 30, 1993, p.
25.
2. “Army Evaluates Homing Vehicle Test Failure,” Aviation
Week and Space Technology, June 13, 1983, p. 119.
3. Clarence A. Robinson Jr., “BMD Homing Interceptor Destroys
Reentry Vehicle,” Aviation Week and Space Technology,
June 18, 1984, p. 19.
4. Ibid., p. 20.
5. Vincent Kiernan and Debra Polsky, “SDI Interceptor Fails
to Hit Target,” DefenseNews, March 23, 1992, p. 8.
6. David Wright communication with authors, based on meeting with
Lockheed officials, April 3, 1992.
7. “SDI Experimental Interceptor Misses Dummy Warhead in
Final Flight Test,” Aviation Week and Space Technology,
March 23, 1992, p. 21.
8. Director, Operational Test and Evaluation, “Navy Theater
Wide (NTW) Defense,” Fiscal Year 1998 Annual Report.
9. Senate testimony of Lieutenant General Malcolm O’Neill,
June 27, 1995.
10. Joseph C. Anselmo, “THAAD Fails Third Intercept,”
Aviation Week and Space Technology, July 22, 1996, p. 31.
11. Director, Operational Test and Evaluation, “Theater High
Altitude Area Defense (THAAD),” Fiscal Year 1998 Annual Report.
George N. Lewis is associate director of the
Security Studies Program at the Massachusetts Institute of Technology
(MIT). Lisbeth Gronlund is senior scientist and co-director of
the Global Security Program at the Union of Concerned Scientists
and a senior research associate at MIT’s Security Studies
Program. An expanded version of this article is available at
http://www.ucsusa.org/global_security/missile_defense/page.cfm?pageID=1026
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