Oxygen generator malfunctions aboard the ISS

The International Space Station's main oxygen generator failed, and the two astronauts aboard the outpost may need to use a backup unit, &to=http://english.pravda.ru/usa/2003/02/03/42893.html' target=_blank>NASA said.

The main oxygen generator malfunctioned on Wednesday, said Johnson Space Center spokesman Rob Navias in a telephone interview. The Russian unit has been operating intermittently due to air bubbles in the system, which Navias said is a "known issue" with the machine, Bloomberg.

There were no problems of any significance during the fourth and final spacewalk for Fincke and &to=http://english.pravda.ru/main/18/88/354/13689_iss.html' target=_blank>Expedition 9 commander Padalka, who will be replaced next month by a fresh crew, reports CBS News Space Consultant Bill Harwood.

While the station's control moment gyroscopes once again had to contend with an unexplained torque that acted to pull the complex out of its proper orientation, Russian rocket thrusters were re-enabled in plenty of time to prevent problems.

Padalka and Fincks had left the orbiting outpost unmanned on Friday, as the international space station's &to=http://english.pravda.ru/main/18/88/354/13689_iss.html' target=_blank>two astronauts popped open the hatch on the Russian side of the orbiting outpost slightly ahead of schedule and got down to work.

The device has operated intermittently for weeks, sometimes choked by bubbles that astronauts can clear.

The generator shut down Wednesday and would not restart Thursday.