Astronauts on board the International Space Station are preparing for a possible spacewalk tomorrow to repair an ammonia leak.
The space agency reported late Thursday that space station crew members had reported seeing small, white flakes floating away from part of the space station's backbone earlier in the day.
NASA confirmed that ammonia was leaking from the station and that the size of the leak is increasing.
The station's six crew members are not in danger and the orbiter continues to operate normally, according to the space agency.
NASA astronauts Chris Cassidy and Tom Marshburn have begun preparing for a Saturday spacewalk to inspect the leak area and hopefully fix it.
The final decision on whether to go ahead with tomorrow's spacewalk will be made tonight.
If the spacewalk does happen, NASA astronaut and station commander Chris Hadfield will act as what the space agency calls spacewalk choreographer. NASA reported that crew members used handheld cameras, and engineers at Mission Control used external television cameras to obtain additional imagery and pinpoint the location of the leak.
According to NASA, the leak appears to be in the same area where another leak was found last fall. Spacewalking astronauts repaired that leak on Nov. 1, 2012.
While the latest leak appears to be in the same spot, NASA has not yet fully concluded that the problem is the same.
Ammonia, a colorless gas made up of nitrogen and hydrogen, is used to cool the space station's power channels, which provide electricity to different systems. Each solar array has its own independent cooling loop. The leak is believed to be in one of the cooling loops.
The leak could force the loop's shut down by Saturday.
The space agency noted that engineers are coming up with a plan to reroute power channels away from the apparently damaged solar array, taking some pressure off that loop and hopefully maintaining full operation of all the systems that have been dependent on that one loop.
Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin, or subscribe to Sharon's RSS feed . Her e-mail address is firstname.lastname@example.org.