Astronauts Suffer Oxygen Scare

Two astronauts working outside the international space station had a scare last night when a suspected oxygen leak in one of their spacesuits forced them to rush back inside.

The spacewalk to carry out repairs should have taken six hours but ended after just 14 minutes, when pressure began to fall rapidly in the main oxygen bottle of US astronaut Mike Fincke.

He was floating outside the station, with Russian cosmonaut Gennady Padalka close by, when the chilling words came from mission control: "You need to return. Something is not right."

Flight controllers said the spacewalk, to repair a damaged circuit breaker, would not be attempted again until next Tuesday at the earliest.

Nasa insisted the two astronauts were never in any danger, but stressed that the problem needed to be understood before they could go back out.

The astronauts, using a combination of American and Russian gear, were trying to install a new circuit breaker needed to restore power to one of the gyroscopes that help keep the station stable and pointed in the right direction.

M 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, and yesterday was not the first time the astronauts had encountered spacesuit trouble.

A malfunction last month of the American spacesuits forced Mr Fincke and Mr 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 pressurised than the US ones and therefore stiffer, were not designed for the type of work planned. And, because communication blackouts were anticipated given the travel distance, the spacemen had to come up with hand signals to convey distress or other messages.

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 made the cosmonaut uncomfortably warm and caused his helmet to become wet.

Mr Fincke and Mr Padalka are the only astronauts currently on the space station, which meant Nasa had to leave it empty during a spacewalk for only the second time in its history, forcing flight controllers on the ground to keep watch over the systems.

That is just one of the risks that Nasa has taken to keep the space station operating without shuttle visits after last year's Columbia disaster.

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.