RAMON LOPEZ / WASHINGTON DC
The US Department of Defense is accelerating its Ground-based Midcourse Defence Segment (GMDS) testing programme following last month's missile defence trial (Flight International, 24-30 July).Orbital Sciences and Lockheed Martin, meanwhile, have been awarded contracts to study alternative concepts for the GMDS interceptor boost vehicle after delays at current launcher contractor Boeing.
Maj Gen Willie Nance, GMDS programme executive officer, says all parts of the hit-to-kill weapon system - formerly the National Missile Defence (NMD) - performed correctly except for the prototype ground-based radar's hit assessment function. He says a software fix has been developed which will be installed before the next GMDS trial, Integrated Flight Test 7 (IFT-7), in October, which will be identical to last month's evaluation.
Early in the NMD programme, the DoD and Boeing selected a commercial booster in place of surplus Minuteman III missiles as the GMDS intercept. It is assembled by Boeing using commercially-available rocket motors and booster stages from Alliant Techsystems and United Technologies Chemical Systems.
But the booster programme is behind schedule and Boeing has awarded Orbital Sciences and Lockheed Martin seven-month study contracts for an alternative launch vehicle. Orbital's concept will be developed from the Pegasus, Taurus and Minotaur vehicles. The rocket would be ground-launched from a silo. If selected, Orbital or Lockheed Martin would produce flight-test vehicles plus 50 boosters for GMDS deployment.
Not all testing has been successful. The first intercept test, IFT-3, in October 1999 did succeed, but flights in January and July last year failed.
Nance plans three additional flight tests next year. Separate check flights of the Boeing booster will begin soon, leading to their use for intercept tests in 2003.
Source: Flight International