The Pentagon conducted two tests September 28 of a prototype radar for the proposed limited national missile defense (NMD) system, consistent with President Bill Clinton's September 1 decision not to proceed with system deployment this year but to continue NMD research and development. In these so-called risk reduction flights, the prototype X-band radar successfully tracked and discriminated among several objects moving through space, according to government and industry press releases. The tests did not involve an intercept attempt, the next of which is scheduled for spring 2001.
In the first test, the radar tracked and sorted 35 different objects, including one re-entry vehicle, while the second test involved fewer objects, including three re-entry vehicles. The X-band radar reportedly employed two new discrimination features in the tests, though a spokesman for Raytheon, which developed the radar, declined to provide further details. The two "target complexes" were designed more to test how the radar would handle a high volume of objects, rather than to stress the radar's ability to discriminate between re-entry vehicles and realistic decoys.
Whether the proposed NMD will operate effectively against sophisticated decoys and countermeasures remains one of the more contested issues surrounding the program. A group of 11 scientists sent a letter September 29 to the head of the Ballistic Missile Defense Organization (BMDO), which oversees U.S. missile defense programs, cautioning against assumptions that countries seeking ICBMs will only be able to develop "trivial countermeasures" at first. Moreover, the group further said masking warheads by putting them in balloons was "not a difficult task" for countries successfully building long-range missiles and nuclear warheads. The scientists also warned that U.S. intelligence might not be able to gather enough data about foreign countermeasures for the United States to develop counter-countermeasures. BMDO Director Lieutenant General Ronald Kadish, in September 8 congressional testimony, had expressed confidence that the NMD system would be able to handle any likely countermeasures it would initially face.