Shuttle Releases Satellite to Form Semiconductor Film

Columbia’s astronauts heaved another science satellite into orbit Friday night, this one to produce thin semiconductor film in the vacuum of space.

As the space shuttle soared 220 miles above the Pacific Ocean, crewman Thomas Jones released the grip of the orbiter’s robot arm on the 12-foot-diameter steel disk, called the Wake Shield Facility.

On Tuesday, the shuttle crew dropped off an ultraviolet telescope to observe stars. The telescope was about 60 miles behind Columbia when the Wake Shield was set loose for three days of free flight.

The release marked the first time a space shuttle has flown in formation with two satellites.

The five astronauts will use radar and lasers to keep track of the two satellites, both of which will be retrieved later in the 16-day flight. Ground stations also will monitor the spacecraft for safety reasons.

To be safe, the National Aeronautics and Space Administration wants at least 28 miles, and preferably 58, between Columbia and the telescope, with the Wake Shield in between.

Scientists will try to produce seven semiconductor-film wafers on the back of the Wake Shield in the super-pure wake created as it zooms around Earth at 17,500 mph.

Atoms of aluminum, arsenic, gallium and indium will be combined, atom by atom, atomic layer by atomic layer, to form the film. The 10,000 to 20,000 atomic layers constituting each 3-inch wafer will be just 1/10th the thickness of a human hair.

The film will be tested for use in transistors and other electronic devices.

Alex Ignatiev, director of the University of Houston research center that designed the satellite, said that the vacuum in the satellite wake is cleaner than vacuum chambers on Earth and should yield faster and better semiconductor film than that now used in computers and other electronics.

If the technique proves feasible, it could be lucrative. Ignatiev said permanently orbiting spacecraft could one day produce up to 10,000 wafers of semiconductor film a year, worth about $40 million at current prices.

Back at Kennedy Space Center, a preliminary check of the booster rockets used to launch Columbia on Tuesday revealed heat damage to the insulation of both nozzles but not as much as on the previous shuttle flight, officials said. The erosion appeared to be minor and within normal levels, although further inspections will be needed.