Shuttle Rescues Satellite From Fiery End

Transforming a moment of high drama into the merely routine, the five astronauts of the space shuttle Columbia caught up with the failing Long Duration Exposure Facility on Friday, grasped it with their 50-foot-long robot arm and tucked it into the cargo bay, culminating a 1.3-million-mile chase and rescue effort that began with liftoff early Tuesday morning.

“Houston, we have LDEF,” Columbia commander Daniel C. Brandenstein radioed laconically at 7:16 a.m. PST.

“You’ve made many scientists quite happy,” capsule communicator Tammy Jernigan radioed back. “Their LDEF experiments are finally coming home.”

While mission specialist Bonnie J. Dunbar slowly rotated the 10.5-ton satellite with the remote manipulator arm, her compatriots Marsha S. Ivins and G. David Low spent the next 4 1/2 hours photographing the 57 separate scientific experiments on the satellite’s outer surface.

Dunbar then gently lowered the 30- by 14-foot satellite into a special cradle in the payload bay, and the crew settled down for another six days of routine scientific and medical experiments before their scheduled pre-dawn landing at Edwards Air Force Base next Friday.

The satellite was latched down at 12:40 p.m., completing the complex exercise without a hitch. Mission control radioed Columbia: “There are a lot of smiling faces here in the control room and a lot of happy PIs (principal investigators) across the country.” LDEF was designed to study the effects of long-term exposure to the hostile environment of space on materials used in the construction of spacecraft and satellites. Launched on April 7, 1984, the satellite was supposed to be recovered within a year, but scheduling delays and then the 1986 Challenger explosion postponed the recovery.

Columbia’s mission was NASA’s last chance to retrieve the satellite. Influenced by solar radiation and the slight drag caused by the ultra-thin atmosphere at its current altitude of about 202 miles, the satellite has been creeping earthward at an accelerating rate, which had reached about half a mile per day. If not retrieved by Columbia, it would have crashed into the atmosphere and burned by about March 6.

When the shuttle caught up with it, LDEF had completed 32,422 orbits, traveling a total of 854 million miles, about the distance between Earth and Saturn. During that time, the glass, plastics, metals, alloys and microelectronic components on its surface have been baked by intense sunlight, frozen by the cold of space, irradiated by cosmic rays, rained upon by cosmic dust, eroded by atomic oxygen and battered by micrometeorites and man-made debris.

Amazingly sharp television pictures relayed to Earth showed a mosaic of blue, silver, black and gold panels on the surface of the 12-sided aluminum satellite, the entire apparatus floating majestically above a backdrop of fluffy white clouds and aqua-blue ocean.

Visual inspection showed that the satellite had suffered a fair amount of normal wear and tear. “It looks like she was rode hard and put up wet,” flight director Al Pennington said in a bit of Texas ranch jargon.

The most visible damage was to some of the thin plastic and foil coverings on the experiment trays.

“A lot of the coverings look like they may be gone,” Dunbar said. Aluminum foil coverings on two experiments on the front of the satellite, Brandenstein reported, “look like they almost exploded . . . . They were just pulled back like a sardine can.”

Researchers believe that a study of the structural weakening caused by this punishment will provide valuable information for designing the proposed $30-billion space station Freedom, as well as for the defensive satellites of the Strategic Defense Initiative. More than 200 researchers in eight countries will examine the materials once they are returned to Earth.

“It looks like we have a really valuable piece of science right there in our grasp,” Pennington said.

When Columbia reached orbit Tuesday, it was 1,725 miles behind LDEF, traveling 172,00 m.p.h. By the time the shuttle began its final rendezvous about 1 a.m. PST Friday, the gap had been closed to 45 miles. Eight short computer-controlled firings of the shuttle’s orbital maneuvering system brought Columbia underneath LDEF and up in front of it a few thousand feet away.

With Columbia’s remote manipulator arm partially extended and the payload bay lights blazing, Brandenstein then manually backed the shuttle slowly up to the satellite, placing the grappling hook on its end within 12 to 18 inches of a special hook on LDEF’s side.

At one point, Brandenstein asked mission control: “You’re not in a hurry, are you?” “No, we’ve got all the time in the world,” Jernigan replied.

Dunbar then lowered the arm and grasped the satellite over the Atlantic Ocean, just off the coast of Brazil.

“They really did a super job,” Pennington said.

After photographing all the experiments to ensure that critical data is not lost if the experiments should be damaged during re-entry or landing, Dunbar--guided by television cameras in the payload bay and on the robot arm--delicately lowered the school bus-sized satellite into the shuttle’s payload bay. The bay is 60 feet long but only 15 feet wide, a mere foot wider than LDEF.

The entire docking and berthing process was also photographed by the crew with special IMAX cameras for a forthcoming film called The Blue Planet.

The satellite will remain in the payload bay until Columbia is returned to the Kennedy Space Center in Florida. Sometime in February, the individual experiments will be removed from it and returned to the experimenters.

The fifth crew member was pilot James D. Wetherbee.