If not, tentative plans for film star Vladimir Steklov to fly to the station in late March with cosmonauts Sergey Zalyotin and Alexander Kalery might be put on indefinite hold.

"The Progress spacecraft will carry enough supplies for three people to stay in orbit, but whether Steklov flies or not remains to be seen," said Valery Olshansky, a chief of the Manned Space Flight Department of the Russian Aviation and Space Agency.

Launched from Baikonur Cosmodrome in Kazakhstan Tuesday, the Progress cargo craft which is loaded with food, fuel and water for the next Mir crew also is carrying enough oxygen to restore air pressure inside the station.

Flying without a crew since last August, Mir has been gradually losing air since a minor leak cropped up on the outpost last year. And if the Progress fails to automatically link up with Mir, Zalyotin and Kalery would fly to Mir in mid-February to do the job manually.

"Nobody will get a free ride to Mir."

Steklov in that case would remain earthbound.

"There would be no place [on Mir] for Steklov for three reasons," said Sergey Krikalev, a veteran Russian cosmonaut who will serve as flight engineer in the first full-time crew to work aboard the International Space Station.

"First, since the Progress would not be able to deliver air supply to Mir in time, the cosmonauts would have to work under the low atmospheric pressure inside the station. Second, the crew might have to use the extra space inside the spacecraft to carry some additional equipment to Mir," Krikalev said.

"Finally," he added, "Steklov just would not have enough time to prepare for flight. And although some officials are considering the possibility of launching Steklov in any case, the decision will ultimately depend on whether he passes all exams at the end of his cosmonaut training."