Supporters of GMD face more questions after computer failure halts vital launch

US missile defence proponents are facing new questions after a pre-flight telemetry glitch halted a long-delayed, critical flight test. The next integrated flight test of the ground-based missile, dubbed IFT-13C, has been rescheduled for mid-September.

The original launch window, from 19-23 August, was to be followed within six weeks by the unveiling of a limited anti-missile shield using GMD interceptors. Although not technically described as an intercept attempt, the aborted test was designed to build confidence in the workings of the overall system and offer the first test launch of an operational booster rocket supplied by Orbital Sciences.

In a routine pre-flight check, the booster rocket's onboard flight computer lost telemetry data for about 200 milliseconds - long enough to prompt Missile Defense Agency (MDA) officials to postpone the launch. The interceptor, which includes the booster and the Raytheon exoatmospheric kill vehicle (EKV), has received a new flight computer.

Meanwhile, the timetable for declaring the initial defensive system on alert has become muddied. It was thought that IFT-13C would provide a system-level dress rehearsal for the planned operational system. The Boeing-led GMD contractor team has been directed to deliver the components for the initial capability by 30 September.

But Maj Gen John Holly, project director for GMD, told last week's space and missile defence conference in Huntsville, Alabama, that the US military's "goal" is to deploy an operational system by the end of the calendar year, and that no test flights should be considered as prerequisite events.

US defence secretary Donald Rumsfeld told conference delegates that he "can't imagine anyone dumb enough to set a firm date" for approving alert status.

The delayed test is to be followed within 60-90 days by an intercept attempt - the first since a failed effort in December 2002. That test also was marred by a minor quality control glitch affecting the guidance system in a surrogate booster for the interceptor missile.

The MDA may face increasing pressure to produce successful results. US Congressman Curt Weldon warns that the $10 billion annual missile defence budget, which represents 2.5% of total US military spending, is a "big target" for Democrat opponents.



Source: Flight International