Russian flight controllers have called an early end to a spacewalk outside the international space station because of a problem with a cosmonaut's spacesuit. It was the first time a spacewalk occurred without a third crewmember inside the outpost, so the U.S. and Russian space agencies took extra safety precautions.
A cooling unit failed inside cosmonaut Alexander Kaleri's spacesuit, causing a slight heat buildup and moisture to form inside his helmet.
He and U.S. astronaut Michael Foale completed only half of the scheduled work on European and Japanese experiments attached to the Russian module. They re-entered the station less than four hours into a planned five-and-a-half hour outing.
U.S. space officials had agreed to the riskier circumstances of the spacewalk after talks with their Russian, European, and Japanese counterparts convinced them it could not wait until U.S. shuttles resume visits with enough supplies to support a third crewmember inside.
So the two crewmen sealed the hatches between compartments and shut down some systems in case an internal emergency prevented them from re-entering. Ground controllers kept watch over the orbiter from Houston and Moscow.
More such unattended outings are now planned after the next two-man crew arrives in late April.
U.S. space officials says they are necessary to prevent a backlog of work that must be done to prepare for the arrival of a European cargo vessel.