NASA ruled Monday that U.S. spacesuits on the international space station are unusable and ordered the crew to use Russian gear instead, adding time and distance to a critical spacewalk next month.

The crew wanted to wear NASA's suits and go out by the closer American hatch to get to a broken power-supply unit on the exterior of the space station, but a cooling problem with the suits made that impossible.

The mid-June spacewalk involves replacing a power control and circuit breaker that last month shut down one of the gyroscopes that stabilize the space station and keep it oriented properly. Only two of the four U.S. gyroscopes are working, the minimum necessary for proper operation; the first one shut down two years ago and cannot be replaced until NASA's shuttles fly again.

Cosmonaut Gennady Padalka and astronaut Mike Fincke spent the past few days, without success, trying to get cooling water flowing properly in Padalka's U.S.-made spacesuit. They could not get a spare suit to work, either. So NASA managers decided to use Russian suits and conduct the spacewalk from the Russian side of the station.

The crew members need to leave from the Russian side because the Russian spacesuits are not compatible with communication equipment in the U.S. air lock.

The Russian hatch is about 80 feet from the bad circuit breaker, located on the American side. The U.S. hatch is 30 feet away.

"It's not as dangerous as a minefield by any means," Fincke said in an interview with the Associated Press. "It's just going to take a fair amount of time to get there and to come back."