Glitch Puts Mir in ‘Chaotic’ Flight

A computer breakdown aboard the Mir space station forced Mission Control on Monday to call off a vital spacewalk to repair the crippled complex, and left it drifting in “chaotic flight” and losing precious power.

The latest misfortune to befall the world’s only working space station has cast further doubt on whether Mir can be salvaged after a devastating June 25 accident that destroyed most of its capacity for scientific research.

Ironically, the failure of the space station’s central computer coincided with a successful manual docking of a Progress supply capsule that suggested human error--not a technical malfunction--as the culprit in the accident nearly eight weeks ago.

But Mir fell out of proper orientation with the sun shortly after the docking, depriving the already energy-starved station of replenishment of its solar batteries.

“Unfortunately, the station’s orientation system is not operational,” Mission Control chief Vladimir Solovev told reporters shortly after the afternoon docking. “The computer will be switched off until morning and there will be no altitude control. It will be chaotic. We don’t know the consequences of this chaotic flight.”

Now that the Progress capsule is attached to the station, the Mir crew can periodically fire up its rocket thrusters to nudge the entire complex into solar alignment when battery power falls dangerously low. The crewmen also have a Soyuz escape capsule to help keep Mir flying right, but using its engines to position the space station depletes fuel reserves and threatens the cosmonauts’ only means of quickly returning to Earth.

By late Monday, the Mir crew had fired off Soyuz’s booster rockets to point the space station partially toward the sun, allowing Mir to charge up its batteries before attempting to reset the orientation.

Docking of the unmanned Progress craft had been postponed Sunday because of a computer shutdown that Russian Space Agency officials then assumed was caused by erroneous transmission of data from Mission Control.

But as Mir commander Anatoly Solovev (no relation to the Mission Control chief) was monitoring Monday what was supposed to be an automated linkup with Progress, the main computer failed, forcing him to switch to the more problematic manual procedure.

An attempted manual docking of a previous cargo craft led to the June collision with Mir that punctured and depressurized the Spektr research module. Since then, Mir has been without 40% of its power-generating capacity and unable to perform the experiments that are the main objective in maintaining a space station.

Mir has lost solar orientation at least three times since the accident, and each failure has resulted in perilous power losses that forced the shutdown of such life-support systems as oxygen generation and climate control.

“This is the reason why the spacewalk that had been scheduled for Wednesday had to be put off for two or three days,” said Mission Control spokesman Valery Lyndin. “The cosmonauts will have to sort out the problems with the computer and make sure it doesn’t go down while they are in outer space. When you are on such an important mission, you don’t want to have to worry about your backside.”

*

A power loss of the type now afflicting Mir “could well cost the lives” of cosmonauts dependent on a reliably functioning mother ship while working in the vacuum of space, Lyndin said.

Space officials have sought for weeks to play down the significance of the string of accidents that has plagued Mir. But nerves are beginning to show among ground controllers struggling to mitigate almost daily disasters.

“We are losing orientation now, and the supply of solar energy will apparently drop to a certain extent,” Yuri Semenov, president of the Energiya rocket corporation that built Mir, told journalists at a news briefing.

The repair mission aimed at reconnecting solar batteries cut off by the June accident has already been postponed repeatedly as space officials scrambled to get the necessary equipment and expertise on board the space station.

If the Mir crew succeeds in restoring full power to the space station, further spacewalks are planned to attempt patching of the hole in Spektr so that the research module can be repressurized and work resumed on any experiments that have survived.

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

‘Chaotic’ Orbit

Russian cosmonauts successfully docked the Progress supply ship--a prelude to extensive repair work later this week. But as docking proceeded, a key computer system failed, sending Mir out of its orbit. Mir’s solar panels lost their orientation toward the sun, depriving the station’s batteries of solar power. The station has been operating on 60% power since a June 25 docking accident damaged the Spektr module’s solar panels.

EVENTS SINCE FRIDAY

1. Friday: Crew circled space station in soyuz, videotaping damage to Spektr module.

2. Sunday: Computer failed during docking of Progress, which Mir commander Anatoly Solovev maneuvered to Mir manually.

3. Monday: Thrusters on Soyuz help stabilize Mir’s orbit.

WHAT’S NEXT

4. Mir’s computer must be fixed before planned repair spacewalk can proceed.

5. Crew plans to reconnect cables from damaged Spektr module and restore Mir’s power to 90% later this week

Progress supply craft: Thrusters on Progress and Soyuz can be used to orient Mir, saving battery power on the station.

Source: NASA, Energiya