Hanging by a thread

the leaking module, and cut or disconnect power cables leading to Spektr’s solar panels. That cut Mir’s power supply roughly by half.

Other technical and human problems have plagued the station since the accident. On Thursday night, the crew were in almost complete darkness. Lights, heating, communications and all non-vital systems were shut down. They were using up the precious reserves aboard a Soyuz “lifeboat” permanently moored to Mir: the lifeboat that in theory could take them back to Earth at a few moments’ notice.

Currently, two Russian cosmonauts, Vasily Tsibilyev and Valery Lazutkin, and US astronaut Michael Foale are aboard the permanent Mir station, 400 km above the Earth. To restore the station to full power, they will have to put in a new hatch plate with holes for the cables to run through.

Last week, a space cargo ship carrying vital repair equipment and supplies to the damaged Mir made a perfect docking. But just as Tisbilyev and Lazutkin were preparing for a space walk, aimed at carrying out the delicate repair work, Russian doctors during a routine medical check-up at the flight control centre, found that flight commander Tsibilyev was suffering from heart problems. So the repair was delayed for 10 days, giving him time for necessary rest.

However, ground controllers monitoring the crew’s health, eventually barred Tsibilyev from the space walk, originally scheduled for Friday or Saturday, after tests showed he had cardiac arrythmia. Mir’s flight control director Vladimir Solovyov asked NASA officials to allow Foale to perform the space walk along with Lazutkin.

NASA has agreed to let Foale prepare to take Tsibilyev’s place. If all goes well with the training exercise, slated for July 21, the crew will attempt the repair on July 24.

Even if all goes smoothly with the planned complex repair work, the problems marring Mir for over 11 years would not be solved. The Russian Space Agency has still not decided what it plans to do with Mir, once the mission ends in 1999, when the 120-ton station will suddenly become the world’s largest piece of space junk.

Left to itself, Mir would eventually make a fiery re-entry into the atmosphere, partly burning up, but also scattering large chunks that would reach the ground, as did pieces of the US Skylab station in 1979, according to NASA experts.

Space experts say the preferable course is to bring down the decommissioned station into the ocean in a controlled way. But doing that with Mir, they believe, will be tricky because of its size, and because some of its rocket engines have not been fired in years. If the crew has to abandon it, decommissioning could become even harder.

Originally, Russian space officials had planned to use their Buran space shuttle to recover the station when Mir was launched 11 years ago. But Buran was cancelled.

The cash-strapped Russian government has been unable to allocate required funds to the Russian Space Agency to meet its budget. Recently Yuri Koptev, chairman of the Russian Space Agency, said that space funding had plummeted 80 per cent since 1989, when the Soviet space programme was still lavishly subsidised. As a result, the agency carried out only 11 of 27 planned launches in 1996, leaving Russian and foreign cosmonauts on board the Mir for longer than their planned stays.

Washington has threatened repeatedly in the past months, to edge Russians out of the International Space Station programme because of Moscow’s chronic failure to fund its share.