CAPE CANAVERAL, Fla. (AP) _ An apparent oxygen leak ended an unusually risky spacewalk just 14 minutes after it began, and sent the international space station's two astronauts rushing back inside to safety.
Flight controllers said the spacewalk _ to repair a fried circuit breaker _ would not be attempted again until Tuesday at the earliest.
Astronaut Mike Fincke had just floated outside early Thursday evening, with cosmonaut Gennady Padalka close on his heels, when the chilling words came from Mission Control: ``You need to return. Something is not right.''
Pressure was dropping quickly in the primary oxygen bottle on Fincke's suit, and the two had to get back inside, fast, and close the hatch.
The spacemen sealed the Russian hatch 14 minutes and 22 seconds after opening it and repressurized the air lock. NASA said the two were never in any danger, but stressed that the problem needed to be understood before they could go back out.
Fincke and Padalka were using an odd mishmash of U.S. and Russian gear, and carrying out a spare circuit breaker. The new breaker is needed to restore power to one of the gyroscopes that help keep the station stable and pointed in the right direction.
Fincke said he was grateful that the Russian specialists caught the leak so quickly.
``We'll just live to fight another day,'' he said.
The mission was fraught with risk, even before Thursday's suit trouble.
A malfunction last month of the U.S. spacesuits on board forced Fincke and Padalka to wear Russian suits and exit from the Russian side of the orbiting complex, more than doubling the travel distance to and from the repair site. The Russian suits, more pressurized than the U.S. outfits and therefore stiffer, were not designed for the type of handiwork planned.
And because communication blackouts were anticipated given the travel distance, the spacemen came up with hand signals to convey distress or other messages.
What's more, NASA had to leave the space station empty during a spacewalk for only the second time ever, forcing flight controllers on the ground to keep watch over the outpost's systems.
These are just some of the risks that NASA has taken on to keep the space station operating without shuttle visits, ever since last year's Columbia catastrophe. The grounding of the shuttle fleet has all but stopped the delivery of replacement parts and reduced the size of the station crew from three to two.
The announcement that the spacewalk was officially over came soon after both crewmen were instructed to take off their spacesuits, about an hour after it all began.
It was a disappointing moment, both on Earth and in space.
``Have some tea, coffee,'' Mission Control kindly told the crew.
Fincke later offered his own condolences to flight controllers, who teased him about setting a record for the shortest spacewalk ever, on his very first stroll into the vacuum.
NASA said the suit pressure itself never faltered and that the problem appeared to be confined to the oxygen tank. Once inside, the spacemen listened for a hiss from the bottle, but heard none.
``We're not exactly clear on what has happened,'' Mission Control radioed.
The last time Russian spacesuits were used, by another crew in February, the spacewalk had to be cut short because of a cooling problem that was so bad that the cosmonaut got uncomfortably warm and his helmet became wet. Padalka and Fincke were using brand new spacesuits, however, for what should have been a six-hour excursion.