15 Mock Missiles Tracked by ‘Star Wars’ Satellite

A research satellite successfully tracked 15 mock Soviet nuclear missiles in a test to help scientists design sensors for the proposed “Star Wars” anti-missile shield, officials said Tuesday.

“We believe we had a very successful mission,” program manager Andy Green said after studying preliminary data from the 12-hour flight, during which the Delta 181 satellite released 14 payloads, with the 15th hoisted by a rocket from Hawaii.

Seven sensors on the 6,000-pound satellite and hundreds at ground stations around the world followed the targets, gathering data that could help to determine whether it is feasible to build a missile response system in space and whether it could distinguish a real missile from a decoy.

Various Backgrounds

The sensors tracked how a missile appears against various backgrounds, such as the Earth, deep space and the portion of the atmosphere just above the ground called “Earth’s limb.”

Green, an Army major with the Strategic Defense Initiative Organization, said one of the satellite’s seven sensors, an infrared device, failed, but there were backup systems on board.

The $250-million mission, launched from Cape Canaveral on Monday, ended early Tuesday, but Green said so much data was gathered that it will take the satellite 10 days to transmit it.

The agency said four of the payloads released by the satellite and the one launched on a suborbital flight from Hawaii contained motors fired to simulate a Soviet rocket as it climbs toward space.

Coasting in Space

The 10 other payloads played the roles of Soviet missiles coasting through space before releasing their nuclear warheads.

Lasers, radars, optical devices and infrared and ultraviolet sensors tracked them around the globe against the various backgrounds.

“One of the things that SDI doesn’t know is what it is we are trying to attack,” said Air Force Col. John Otten, assistant director of the SDI kinetic energy office. “What are the objects, what do they look like, in what context will the background be? The data will allow us to understand the arena in which we’re going to operate. . . .”