The Pentagon is planning to make its next attempt to destroy a mock strategic warhead in space more challenging than previous ground-based midcourse missile defense tests by increasing the number of balloon decoys accompanying the target from one to three.
In past intercept tests, the Pentagon has deployed only a single large balloon decoy with the target warhead, but in a test scheduled for mid-March, two smaller Mylar balloons will also be deployed, according to a spokesperson from the Missile Defense Agency (MDA), the body overseeing U.S. missile defense efforts.
The next test will mark the sixth intercept attempt for the Pentagon’s ground-based midcourse system, which has scored three hits in five attempts since October 1999. The last test, a hit, occurred December 3.
Days before that test, Lieutenant General Ronald Kadish, the MDA’s director, told reporters that, if the test succeeded, the Pentagon would have greater “confidence to move on to more aggressive and complicated [testing] efforts.” He said that the “obvious” way of making tests tougher would be to add “more countermeasure type of activity.”
A decoy is one kind of countermeasure that a potential adversary could use to try to circumvent a future U.S. missile defense system. Another would be hiding a warhead in a cloud of radar-reflecting chaff.
Previously known as the national missile defense system, the ground-based midcourse system is comprised of a powerful booster that carries an exoatmospheric kill vehicle (EKV) into space to collide with an incoming target. The Pentagon plans for the system ultimately to use a combination of satellite systems and an advanced radar, none of which currently exist, to track and discriminate warheads and decoys. The EKV is also equipped with infrared sensors to help it select the right target in the final seconds before a collision. During tests, the Pentagon has preprogrammed the EKV with information about test objects, such as their relative brightness, to help it strike the proper target.
Missile defense testing plans in 1997 called for 9-10 objects, including balloons of various sizes, to accompany a mock warhead in early intercept testing. But the Pentagon reduced that number to three balloons in 1998 and then to one in July 1999. Critics of missile defense charged that the Pentagon deliberately “dumbed down” the tests to avoid failure because it knew the system would be unable to pick out the mock warhead among so many objects.
Pentagon officials defended the reduction in decoys, contending that it is wise to start with tests with as few variables as possible so that, if something went wrong, it would be easier to identify the problem and fix it. The Pentagon said that testing would be made incrementally tougher once the system proved capable of hitting a target in space.
The MDA spokesperson said that including two smaller balloons in the next test would “further stress” the defense system’s EKV and prototype X-band radar, which relays updated target-tracking information to the EKV.
In interviews, two former top Pentagon officials from the Clinton administration concurred. Jacques Gansler, a former undersecretary of defense for acquisition, technology, and logistics, stated that the additional balloons would “add discrimination complexity for both the [X-band] radar and the interceptor.”
Philip Coyle, former director of the Defense Department’s office of operational test and evaluation, said that adding the two small balloons would give the missile defense system a “more complicated” view. However, Coyle also said that, although introducing the two small balloon decoys into testing moves the program in a more aggressive direction, the Pentagon still has “a long way to go.”
Describing the two small balloon decoys as “unsophisticated” countermeasures, Coyle said that, if the new balloons’ diameters are about the same as the target, they might appear to the missile defense system as similar to the mock warhead in “some viewing angles, but not the correct overall shape or reflectivity.”