Two cosmonauts blasted off yesterday to join a spacecraft with breathing problems. A new Russian crew and repair kit in a Soyuz spacecraft headed for the elderly Mir space station in which the oxygen generating system had, once again, failed.
Mission control in Moscow took the bad news calmly. "This has happened a thousand times before, so it is not worth making a fuss about," said Mr Viktor Blagov, a flight director. "We are concerned, yes, we are worried, but have immense experience on our shoulders in dealing with this."
The oxygen generators failed before, in February. The crew burned lithium perchlorate candles to release oxygen as a byproduct. One of these started a fire which forced the crew into gas masks.
But the main problem that the new crew must face is the aftermath of a collision on June 25th between Mir and its own unmanned cargo supply vessel Progress which left a damaged module, power failure and a spaceship tumbling out of control.
Antony Solovyov (49) and Pavel Vinogradov (43) will arrive tomorrow night to take part in a set of complicated manoeuvres while orbiting the planet every 90 minutes. The existing crew - two Russians and the British-born US astronaut, Michael Foale (40) - will today uncouple a moored Progress craft which they have been using as a skip to collect waste, and "park" it nearby. The new crew will circle Mir to look for signs of damage from the collision, and then dock where Progress used to be.
There will be space walks to examine the damage and begin repair work. On August 14th, the Russians in the existing crew, Vasily Tisbliyev and Alexander Lazutkin, will board their own Soyuz "lifeboat" and fall back to Earth. Dr Foale and his new colleagues will move the new Soyuz to a different berth, and then shift the "parked" Progress craft back to its old dock. It will stay there till October. By then, the space shuttle Atlantis will have docked to deliver a new astronaut - and relieve Dr Foale.
Manoeuvres in space are always a problem. Things went wrong in June because there were worries about the automatic docking system. When the Mir crew tried to practise manual docking with the Progress craft, it hit one of Mir's modules at three metres a second - 10 or 20 times too fast. It dislodged a solar panel and then hit and punctured the module, sending the whole space station tumbling. Mir lost more than 63 kilograms of oxygen. Pressure dropped. The crew slammed a hatchway shut and cut off their own power.
Mission control back in Moscow have been replaying the accident on simulators. To their alarm, other cosmonauts have also been unable to avoid collisions.
Meanwhile, the crew in orbit have battled on with low power, bad light and shaky life support systems in what has turned into an endurance test in space, provoking concern for their safety.
But the chances are they will persevere. "I would think the Russians will want to keep it going as long as possible, and the Americans seem to be supporting that," said Dr Andrew Coates, of University College London's space science laboratory. "But between the two space agencies, they have got to decide at some point when enough is enough. I don't think they are at that point yet."