Space Walkers Attach Tools for Satellite Rescue

Working like clumsy surgeons wearing backpacks and mittens, two astronauts ventured outside the space shuttle Discovery on Tuesday and strapped two homemade snares to the tip of the craft’s robotic arm in preparation for today’s attempt to save an $80-million satellite.

The three-hour, unrehearsed space walk paved the way for a real surgeon aboard the Discovery, Dr. M. Rhea Seddon, to reach out with the robotic arm this morning and try to trip a lever on a Hughes communications satellite that is drifting uselessly in orbit.

Lever Believed Closed

Engineers believe that the lever, on the side of the spinning satellite, did not open when the satellite was released from the shuttle Saturday, thus failing to start a series of maneuvers, including firing the satellite’s powerful rocket.

The awkward, tedious task of strapping the crude devices on the tip of the robotic arm was carried out cheerfully by S. David Griggs, 45, a former Navy fighter pilot, and Jeffrey A. Hoffman, 40, an astrophysicist.

“Is that beautiful or is that not beautiful?” Hoffman asked as he praised his own efforts to attach one of two devices to the end of the arm. The devices, called “fly swatters” because that is what they resembled in their early stages of design, were made by the Discovery’s crew from plastic book covers and other cannibalized materials aboard the shuttle.

The space walk went off as though it had been rehearsed for months, although it was the only unrehearsed space walk in U.S. space program history. The impromptu performance surprised many veteran space watchers who thought the National Aeronautics and Space Administration would never attempt such a maneuver without first practicing it extensively on the ground.

“Let’s call it a day,” Hoffman said after the task had been completed.

“OK, great, that’s exactly the way we had hoped it would all end up,” Mission Control in Houston told the astronauts after examining their handiwork with the Discovery’s television cameras.

Before returning inside the shuttle, the astronauts relished a few moments of freedom. At one point, Griggs drifted over the side of the shuttle’s cargo bay and disappeared completely at the end of his tether.

“Dave, get back into the bay,” he was ordered.

“We’re very, very happy,” Mission Control told the astronauts at the end of the three-hour extravehicular activity.

The real test, however, was to come today just after 6 a.m. PST, when Seddon--the only woman in the crew of seven--was to attempt a delicate operation. From inside the Discovery, the 37-year-old emergency room veteran was scheduled to try to move the end of the robotic arm to within inches of the satellite to snag a four-inch lever. The trick is to snag the lever, pulling it open, without hitting the satellite and damaging its delicate solar cells or knocking it into a wobble.

The operation must be done within a 6 1/2-minute “window,” just as the satellite crosses the Equator over the Atlantic Ocean. If Seddon should miss that window, the satellite would not end up in the right orbit, even if she should successfully trip the lever.

If the lever is successfully tripped, the Discovery must drop away quickly, in order to be at least 20 miles away when the satellite’s rocket--essentially the same as that used to power a Minuteman missile--fires automatically 45 minutes later.

Engineers at the Johnson Space Center in Houston designed the “fly swatters” to be strong enough to snare the lever but weak enough to break after the lever opens, thus freeing the arm from the satellite.

The rescue exercise has extended the mission from five days to seven and is giving Sen. Jake Garn (R-Utah), who is flying as a congressional observer, extra time to see how astronauts improvise to respond to unexpected situations.

Garn, 52, the first elected official to fly in space, is the chairman of the Senate subcommittee that oversees NASA’s budget. He has taken a back seat throughout the flight, using his time primarily to carry out experiments on space sickness.

Meanwhile, weather in Florida has been improving, increasing the chances that the shuttle will be able to land Friday at Kennedy Space Center, and not at the backup landing field, Edwards Air Force Base in California.