Shuttle Crew Solves Recorder Problem : Space: Astronauts follow 97-step salvage operation in last-ditch effort to retrieve information from inoperable instruments.

KENNEDY SPACE CENTER, Fla. — Discovery’s astronauts succeeded in getting data from three scientific instruments to the ground Saturday after splicing wires and rearranging cables in a 97-step salvage operation.

It was a desperate, final attempt to retrieve information from the instruments, which became virtually useless after their data recorders failed shortly after launching a week ago. Controllers now hope to obtain about half of what the investigators initially sought in what remains of the flight.

The “Star Wars” research mission is expected to end Monday.

“By God, we put it together and it’s working great,” said Air Force Capt. Lindley Johnson, a program director. “We’re getting excellent data.”

Johnson said there were a few minor problems still to be resolved, including getting accustomed to the periodic loss of radio contact.

Mission Control’s Jan Davis informed the seven astronauts of the strong link between the space shuttle and the ground about 2 1/2 hours into the electrical repairs.

The work involved rerouting data from the instruments through a flight deck computer panel, through 20 feet of TV cable, through an antenna, through a satellite to the ground.

“It is one of the more involved things we’ve ever tried to do,” National Aeronautics and Space Administration flight director Bob Castle said.

The link bypassed the two data recorders, which mysteriously stopped working hours after Discovery blasted off last Sunday into an orbit 161 miles above the Earth. Numerous repair attempts failed.

Johnson said it appears as though a contact on a connector for joining ground test equipment to the recorders grounded out, causing the tapes to wind off their reels.

Provided the link remains strong, controllers expect to collect about 4 1/2 hours’ worth of high-priority data from an X-ray detector that had been crippled by the recorder failure. Before trouble struck, scientists had originally planned to collect about 10 hours’ worth of information, said Rob Kelso, a NASA official.

Ed Fenimore, an astrophysicist at the Los Alamos National Laboratory in New Mexico and the principal investigator for the X-ray detector, is conducting the experiments for the Energy Department, which wants celestial X-ray readings to differentiate between natural and nuclear sources of X-rays.

The findings could help verify whether nuclear test treaties are being observed.

Also hindered by the recorder failure were an instrument to study the horizon in ultraviolet wavelengths and a contamination-measuring device. Two other instruments constituting the Defense Department payload have their own data-collecting devices and were unaffected.

The five instruments are valued at a total of $160 million.

The Pentagon also has a $94-million infrared probe aboard Discovery. The probe spent 1 1/2 days in orbit studying the shuttle’s engine exhaust plumes for the Strategic Defense Initiative, also known as “Star Wars.”

Pentagon officials ordered the experiments to gather information needed to develop sensors for tracking and destroying enemy missiles. Findings from the plumes and atmospheric light, or aurora, will be secret, unlike most information gleaned from the mission.

Kelso said that all scientific observations will be halted late tonight so that the astronauts can begin preparing for the landing, scheduled for Monday afternoon at Edwards Air Force Base, Calif.