CAPE CANAVERAL, Fla. (AP) - The crew of Russia's battered Mir space station is down to only 11/2 to two months of drinking water and could run out if a NASA shuttle doesn't get there on time in late September.
A Russian cargo ship also is supposed to take up water in early October, but that might be too late.
Normally, humidity aboard Mir is condensed and recycled into drinking water. But the crew can no longer rely on the system because the water may be contaminated by antifreeze fumes from leaks months ago in the cooling system.
Space officials won't know for sure whether the water is safe until returning cosmonauts bring back a sample later this week.
If Mir's water-reclamation system remains unusable, the drinking water stored in bags on board probably will last only until late September, said Frank Culbertson, manager of NASA's shuttle-Mir program. Otherwise, there should be enough until early October.
News of the dwindling water supply came Tuesday on top of continued problems with Mir's air supply: the new Elektron oxygen generator won't work, possibly because of a clog, and the spare can't work because of a lack of power.
Mir was reduced to half power after a cargo ship slammed into it on June 25 and ruptured a pressurized lab module.
The four Russians and American Michael Foale are relying on solid-fuel canisters to generate oxygen, but they are not exactly reliable. One such canister burst into flames in February.
"At this moment, the Elektron is the more immediate problem, although I believe it will be resolved in the near future," Culbertson said. "I think the overall water situation, in terms of how much is on board and how far it will stretch, is something we're going to have to watch carefully."
The two cosmonauts leaving Mir on Thursday in one of the two attached Soyuz capsules will bring back a water sample. Scientists are optimistic the water will be found safe to drink.
"But until they get verification of that, it's not likely that they'll get the crew to go ahead and drink it," Culbertson said.
The power shortage, meanwhile, has knocked out Mir's urine-reclamation system. That system was providing a couple quarts of water a day, although it was not used for drinking or cooking.
NASA is aiming to launch space shuttle Atlantis around Sept. 25 or 27. Once in orbit, Atlantis will produce thousands of gallons of water for transfer to Mir.
Culbertson said preparations are going well for a spacewalking foray into the ruptured, airless lab module on Aug. 20. Mir's two fresh cosmonauts will attempt to reattach cables and restore much of the lost power.
But Culbertson said he doubts Spektr will ever be usable again, even if the crew can plug the holes.
"We would have a very hard time certifying any repair that was conducted on orbit," he said.