Missile Defense Booster Flies

Wade Boese

With the target date for deploying the initial elements of a strategic ground-based missile defense system about one year away, the Missile Defense Agency (MDA) conducted on August 16 the first flight test of a prototype booster that is meant to play a key role in the system. MDA and the booster’s manufacturer, Orbital Sciences Corporation, declared the test a success.

The three-stage booster, which was launched from Vandenberg Air Force Base in California, traveled approximately 5,300 kilometers and reached a peak altitude of nearly 1,900 kilometers. No intercept was attempted as part of the test, which was limited to checking whether the booster would work properly and hold its course.

The booster’s role in the planned system is to lift an exoatmospheric kill vehicle (EKV) into space. After the booster’s third stage burns out, the EKV is supposed to separate from the booster, home in on an enemy warhead, and collide with the target in a powerful collision.

Development of the booster is far behind schedule. The Pentagon initially aimed to have the prototype booster take part in intercept testing in early 2001. But production delays and a December 2001 booster flight test failure forced MDA to conduct all eight of the system’s intercept tests—five of which have succeeded—with a less powerful, two-stage booster.

Testing with a three-stage booster is seen as critical for the system because the two-stage booster is too slow to carry out intercepts at speeds expected in a real attack. Yet, an independent review group, known as the Welch Panel, questioned in 1999 whether the EKV would be able to withstand the greater shock loads from a more powerful, three-stage booster.

The Orbital Sciences Corporation booster, an upgraded version of a rocket that the company flight-tested in February, is one of two models being evaluated for potential use in the missile defense system. The other booster is being built by Lockheed Martin, which took over work on it from Boeing following the December 2001 test failure. Lockheed Martin’s booster is set for its first flight test in September or October 2003.

If the Lockheed Martin booster succeeds in its upcoming test, it will join the Orbital Sciences Corporation booster in having one more non-intercept flight test this fall. MDA is planning to conduct two intercept tests in 2004 before the missile defense system’s October 1 deployment goal, but which boosters will be used remains undetermined.