Power to Mir’s Navigational System Disrupted Again

Russia’s troubled Mir space station suffered another malfunction Thursday that disrupted power to its navigation system for the second time since the complex was plunged into crisis June 25 by the worst accident in its 11-year history.

Power to the gyroscopes--which keep the space station oriented toward the sun so its solar panels can collect energy--was suddenly shut off, Russian and U.S. space agency officials reported.

The Mir crew fired up the craft’s rocket engines to keep it properly aligned, using a method usually reserved as a backup because it consumes fuel instead of battery power that can be replenished.

“This has happened many times in the past, and there is no danger in this situation for the crew,” said Sergei K. Gromov, spokesman for the Energiya enterprise that designed and built Mir.

He likened the malfunction to “blowing a fuse” and noted that the spare parts needed to repair this problem are on board Mir for use as soon as the three crew members determine the cause of the malfunction.

Thursday’s power failure in the navigation system was the second since last month’s accident. In both instances, the system’s data-processing unit misread the battery-power supply and automatically shut off energy to the gyroscopes.

U.S. astronaut Michael Foale, Mir commander Vasily Tsibliyev and flight engineer Alexander Lazutkin were working on the problem and expected to have it repaired today or Saturday, said Rob Navias, a spokesman for the National Aeronautics and Space Administration in Houston.

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At the very least, the latest glitch has been a distraction for a space trio that has been operating in crisis mode with low power for nine days while waiting for vital supplies and repair equipment to restore the space station to working order.

The Mir’s Spektr research module, where Foale worked and slept, was punctured and depressurized when an unmanned supply capsule crashed into it during a docking practice. Since then, the Spektr module has been sealed off.

Energy from the solar arrays attached to Spektr has been lost, reducing power aboard the space station by as much as 40%.

That has meant curtailment of all scientific experiments, which are the main purpose for maintaining the aging space complex until the international Alpha station, now under construction, is ready in 1999.

The Russian Space Agency plans to send up another supply capsule early Saturday to replenish fuel, water, food and equipment aboard the crippled Mir. Also on board will be a specially designed hatch cover that will allow the crew to reconnect electrical cables from Spektr to Mir’s main power grid.

Tsibliyev has repeatedly expressed doubts about prospects for a successful repair operation, noting that he and Lazutkin will have to work in the dark and narrow confines of the airless Spektr module to reconnect the batteries.

Simulations of the repair mission are being conducted at Russia’s space training center at Star City, but none of the current Mir occupants has experience with the procedures.

Among the fears being expressed by space officials is that the cosmonauts’ pressurized spacesuits will prove too cumbersome for working inside Spektr and that equipment and debris floating in the depressurized module could puncture their protective clothing, exposing the men to the deadly vacuum of space.

Officials are considering having the cosmonauts don an older and snugger style of spacesuit for their work inside Spektr.

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But there could be safety complications if the repair mission fails and the crewmen are forced to return to Earth in the Soyuz escape capsule docked at Mir.

A leading daily newspaper, Sevodnya, suggested in its latest edition that space officials have failed to accurately convey the severity of the problems aboard Mir.

“It is very dangerous for both the lives of the cosmonauts and Mir’s future existence,” the newspaper contended, quoting space agency sources.

Space agency officials here and in the United States have disclosed privately that there is strong pressure to persevere with the Mir mission, as long as the crew members’ lives are not threatened, because to abandon the station would probably spell the end of Russia’s manned space program.