Space Station Crew to Test New Oxygen Generator
The International Space Station's U.S. Oxygen Generation System takes center stage in this image from January 2007. NASA astronaut Sunita Williams, then an Expedition 14 flight engineer, looks through an opening as the system's rack is rotated.
Credit: NASA.

HOUSTON -- Astronauts aboard the International Space Station (ISS) will test a new U.S. oxygen generator that will prove vital for the outpost?s expansion to larger crews.

Working in tandem with flight controllers on Earth, the station?s three-astronaut Expedition 15 crew is expected to activate the outpost?s U.S.-built Oxygen Generation System for the first time since its delivery last year.

?We expect to generate, for the first time, U.S. oxygen from water,? said NASA?s deputy ISS program manager Kirk Shireman during a Tuesday briefing.

Shuttle astronauts delivered the U.S. oxygen generator to the ISS in July 2006, but the new hardware had to wait until another mission?s crew - last month?s STS-117 astronauts aboard Atlantis - installed and opened a new hydrogen vent valve outside the station?s Destiny laboratory. A software upgrade last week primed the oxygen generator for action, thought it won?t be required for full use until the station ramps up to its full six-person crew in 2009.

?This is just a test,? Shireman said. ?If things go well, we expect to generate about 40 hours of oxygen.?

Today?s check is slated to begin in mid-afternoon, around 3:00 p.m. EDT (1900 GMT), NASA said.

The 1,500-pound (680-kilogram) U.S. oxygen generator uses electrolysis to separate water into breathable oxygen and waste hydrogen, which is dumped overboard via a vent in NASA?s Destiny laboratory aboard the ISS. A similar Russian machine, dubbed Elektron, performs the same function aboard the station?s Russian-built segment and has served as the orbital laboratory?s primary oxygen generator to date.

The current Elektron and oxygen stores aboard docked Russian cargo ships are sufficient to meet the life support needs of current crews, but future ISS expedition astronauts will find the U.S.-built oxygen generator vital for normal operations, NASA said.

?It?s an additional capability and an additional redundancy level,? Shireman said of the U.S. system right now. ?[But] it?s a major technology that?s required to produce oxygen to support the six-person crew, and it?s a big step for us.?