Astronauts Will Attempt ‘Hot-Wire’ Bypass Maneuver to Salvage Stranded Satellite

Two space-walking astronauts will try to “hot wire” a stranded communications satellite in August to give ground controllers a shot at sending it into a proper orbit, it was announced Friday.

The salvage plan--which is given only a slim chance of succeeding--is the result of lengthy negotiations between the National Aeronautics and Space Administration, which launched the satellite last month from the shuttle Discovery, and Hughes Communications Inc., which built and owns the satellite. The cost of the mission is still being negotiated and is to be borne by Hughes, company spokesman Richard Dore said.

The astronauts will have to stop the spinning Leasat satellite, open it up and bypass the system that was supposed to have fired its rockets automatically 45 minutes after it was released from the shuttle’s cargo bay. The bypass should permit ground controllers to send the communications device on to geosynchronous orbit 22,300 miles above the Earth.

‘Fly Swatters’ Fail

Crewmen aboard the shuttle attempted to save the satellite after it was released in April but failed. In the first unrehearsed space walk in the history of the U.S. space program, two astronauts attached crude devices made by the shuttle’s crew to the tip of a robotic arm. The devices, called “fly swatters,” were used to try to trip a lever on the side of the satellite in hopes of bringing it to life. It turned out, however, that the lever was not the villain.

Dore said no one knows what went wrong with the satellite, which was designed to be launched from the shuttle. Because the exact problem is unknown, the plan worked out between Hughes and NASA will “bypass all hardware likely to have been the cause of the Leasat failure.”

Because the satellite is still attached to its unfired rockets, which are similar to those used to power intercontinental ballistic missiles, the mission will not be without risk. That is one reason that the plan must still be approved by a NASA advisory committee on safety.

Engineers also are concerned about damage that the satellite may have sustained while floating in space.

“In its dormant state, the satellite is experiencing temperatures well below the design and test limits of the liquid and solid propellant systems, electronic units, battery and all other components,” the company said in a statement. “This factor, combined with the complexities of the modifications, appreciably limits the chances of success.”

In Earth’s Shadow

Normally, the satellite would have been spinning at a higher speed, thus exposing its entire surface to solar radiation, keeping temperatures at an acceptable level. And because it was left stranded in a low orbit, it has been in the Earth’s shadow for up to 72 minutes at a time, Dore said.

“It got a lot colder than we like it to get,” he said.

In the statement, Hughes said agreement to attempt the rescue has been reached with European insurance underwriters, and “negotiations are continuing” with U.S. underwriters. The satellite was insured for between $80 million and $85 million.

The rescue will be attempted during a shuttle mission scheduled for launch from the Kennedy Space Center in Florida no earlier than Aug. 24, the earliest date that the shuttle could be launched into an orbit that would make it possible to rendezvous with the satellite. The flight is scheduled to last eight days to allow time for the rendezvous and rescue attempt.

“We’re really looking forward to it,” said Discovery commander Joe Engle, who has been training for the complicated mission in Houston. “This is what spaceflight is all about.”

Different Operation

This will be the second shuttle flight devoted to rescuing stranded satellites, but the operation this time will be quite different from the successful retrieval of two smaller satellites last November. During that mission, astronauts Joseph P. Allen and Dale A. Gardner wore jet-powered backpacks when they captured the satellites and arm-wrestled them aboard the shuttle. Those satellites, however, had fired their rockets but failed to reach proper orbit, leaving them in a more benign state.

That is not the case with Leasat, however. Because its rockets never fired, it is still considered armed and potentially dangerous, virtually ruling out any attempt to retrieve it and bring it back to Earth.

That means astronauts James D. Van Hoften and William F. Fisher will have to modify the satellite in space, wearing bulky spacesuits that make even the simplest chores exceedingly difficult.