The international space station's main oxygen generator malfunctioned again on New Year's Day, forcing astronauts to use a backup oxygen supply.
NASA astronaut Leroy Chiao and Russian cosmonaut Salizhan Sharipov are using oxygen that arrived as part of a Christmas Day supply shipment and have enough to last many months, James Hartsfield, a spokesman for the Johnson Space Center in Houston, said in an interview.
Chiao and Sharipov have been troubleshooting gas bubbles in the system's plumbing supply, which caused it to fail, according to the space station's Web site. The pair used spare parts to partially repair the generator in October and have been waiting for supplies to fully restore the system.
"There are still many things they can do to attempt to recover it," Hartsfield said. "This is not that unusual, and it requires troubleshooting maintenance of this type."
The Russian Elektron oxygen-generation system uses wastewater to make oxygen for breathing and sends hydrogen into space, Hartsfield said. The astronauts' efforts to fix the system on Tuesday failed because of an equipment problem, according to the Web site.
The next supply shipment is scheduled to arrive in eight weeks, Hartsfield said.