A computer failure aboard the ailing Mir space station sent the ship spinning chaotically in orbit yesterday, forcing engineers to shut off all but vital life support systems, space officials said.
"We have turned off all energy-consuming equipment and only left life-support systems operational," the flight director, Mr Vladimir Solovyov, told reporters.
"With this computer fault today we are bracing ourselves for a tense situation with the battery buffers, our energy reserves," he said. "Only God knows how long the reserve batteries on Mir will last."
Mir's computer failed a few minutes before it docked with the Progress resupply ship, forcing its commander to take manual control of the docking, which was completed at 4.53 p.m. Moscow time (12.53 p.m. Irish time).
With the computer failure Mir also lost its orientation towards the sun, which the station's solar panels need to face to create energy, Mr Solovyov said.
"There were no human errors in this situation. It was a technical malfunction. The cosmonauts reacted normally to this," he said.
An earlier computer breakdown a month ago sent Mir spinning around for a day until the crew managed to fix it. That fault was caused by a crew member who had mistakenly unplugged a key cable.
The latest in the seemingly unending wave of problems aboard Mir forced Mission Control to postpone vital repairs planned for tomorrow aimed at restoring energy to the 11-year-old station.
Mir has run on partial power since it collided with a previous Progress cargo ship on June 25th in the worst accident in its history. Several areas of the station have been out of action since then.
"Unfortunately we have to move back repairs by two or three days," Mr Solovyov said. "The repairs will be a five-hour-long operation and we cannot begin this operation without coming to terms with what has happened."
The Progress redocking was tense until the last few seconds.
"At a distance of 260 metres there was a hitch on the on-board system and therefore the command to go to manual pilot was given," Mr Yuri Semyonov, general director of the Energia rocket corporation, said. "The crew did a great job with the manual docking."
Poor visibility added to the woes of Commander Anatoly Solovyov, now on his fifth flight on the space station.
"The commander, Solovyov, made the operation very carefully as visibility was very bad from a distance of six metres and that's why he decided to increase the distance to Progress from six to 12 metres during the last few seconds before he docked the Mir station with Progress," the flight director said.
After the redocking yesterday the atmosphere was tense at Mission Control, where top experts were discussing the situation near the computers and monitors of the operations centre. On Sunday the Progress redocking was cancelled because of a computer programming error on Progress.
Progress delivered oxygen, food, water and tools to Mir on July 7th and is now filled mostly with rubbish. Re-docking a rubbish-filled module will provide better balance for Mir and protect an uncovered hatch from prolonged solar exposure.
The threat of fog forced NASA yesterday to postpone for one day the homecoming of the space shuttle Discovery after a science mission.
The $2 billion spaceship had been scheduled to return to Earth shortly after sunrise yesterday, but forecasters were concerned that the runway at the Kennedy Space Centre would be obscured by fog.
The shuttle will make another landing attempt today.