NASA Revives Air-Scrubbing System on Space Station

NASA engineers have revived a vital air-scrubbing system on the International Space Station and are hunting for the source of the glitch that sent it offline.

The American-built air scrubber, called a Carbon Dioxide Removal Assembly (CDRA), shut down Saturday, sending engineers on Earth scrambling for a fix while a record 13 people work aboard the space station.

They ultimately revived the life support gear in a manual mode, one that requires extra flight controllers on Earth to keep it working. Normally, the system runs automatically and NASA is hopeful that a software patch expected late Sunday will recover that ability as well.

A heater in the system got stuck on and tripped a circuit breaker, shutting the system down, mission managers said.

?We?re still trying to determine exactly what the root cause of the problem was,? space station flight director Brian Smith told reporters in a Sunday briefing. ?But in the meantime, we?re doing a great job managing the [carbon dioxide].?

Two air-scrubbing systems, NASA?s CDRA device and its Russian counterpart Vozdukh, are both required to work properly to support the space station?s full six-man crew, as well as the additional seven astronauts who are visiting from NASA?s shuttle Endeavour.

Smith said that at no point did mission managers plan to cut Endeavour?s stay short at the space station if the CDRA system wasn?t restored. The station has a stockpile of extra air-scrubbing canisters that could have supported the large joint crew for the rest of their docked mission, he added.

The space station doubled its crew size from three to six people in late May, and then temporarily jumped to 13 when Endeavour arrived. With each population boost, the amount of time engineers have to respond to life support system glitches like the air-scrubber system?s goes down, Smith said.

?So this problem got immediate attention,? he added.

Endeavour is due to leave the space station Tuesday and return to Earth July 31 to complete a 16-day mission that delivered a new crewmember and Japanese experiment porch for the station?s $1 billion Kibo laboratory.

On Sunday, astronauts used robotic arms on the station and Endeavour to pack up a Japanese cargo carrier that was used earlier in their mission to deliver the first experiments to the orbiting lab?s new Kibo porch. The crew is also preparing for the spaceflight?s fifth and final planned spacewalk, which is set for Monday.

• Video - Population Boom on the Space Station
• Video - The Kibo Lab: Japan's Hope in Space - Part 1, Part 2
• SPACE.com Video Show - The ISS: Foothold on Forever

SPACE.com is providing continuous coverage of STS-127 with reporter Clara Moskowitz and senior editor Tariq Malik in New York. Click here for mission updates and SPACE.com's live NASA TV video feed.