NASA: Spacesuit's Smoky Smell Prompts Spacewalk Ban

NASA imposed a hiatus on spacewalks this week as engineers hunt for the source of smoke-like smell in a U.S. spacesuit used in a recent ground test.

The self-imposed ban was prompted by an apparent U.S. spacesuit glitch during a Friday test at NASA's Johnson Space Center in Houston, Texas, space agency officials said. It could be lifted as early as this week, clearing the way for astronauts to stage two planned spacewalks outside the International Space Station (ISS) next week, they added.

"So far, they have not found any evidence of a combustion event, and not found any hardware damage," NASA spokesperson Brandi Dean told SPACE.com Tuesday.

According to a Monday ISS status report, an astronaut smelled a smoke-like smell inside a NASA spacesuit while working inside a test-version of the station's U.S. Quest airlock. The exercise is a standard activity to familiarize ISS astronauts with NASA's Extravehicular Mobility Unit (EMU) spacesuits, Dean said.

"During the test, the astronaut smelled just a little bit of smoke," Dean said, adding that even a slight odor is cause for concern given the spacesuit's 100 percent oxygen environment. "They got the crewmember out of there in less than a minute."

NASA imposed a ban on all U.S. spacewalks as a precaution in case Friday's glitch was a sign of a generic flaw in the agency's spacesuits.

"Thus, the on-orbit EMUs are No Go," stated Monday's status report.

Engineers have performed a series of tests on the afflicted spacesuit and examined its history to root out the origin of the smoke-like smell. Some possible sources include the suit's carbon dioxide-scrubbing canister and the off-gassing of heated materials, though additional analysis is still under way, Dean said.

Spacesuit engineers will present their findings to a mishap investigation board on Wednesday, she added.

NASA hopes to clear its U.S. spacesuits for use soon to allow ISS Expedition 16 commander Peggy Whitson and flight engineer Dan Tani to step outside the space station on Nov. 20 and Nov. 24 on a pair of critical spacewalks to attach cooling and power system lines to the Harmony connecting node.

The astronauts will move the node and its recently attached shuttle docking port to the front of the station's U.S. Destiny laboratory early Wednesday using the space station's robotic arm.

Any lengthy delays to Expedition 16 crew's planned spacewalks next week could stall an already hefty work schedule to ready the ISS for NASA's planned Dec. 6 launch of the shuttle Atlantis to deliver the European Space Agency's Columbus laboratory. NASA is already working to cull five days' worth of work from the station crew's schedule to allow Atlantis's STS-122 crew to launch during December's slim, one-week window.

"The main thing is getting the flight rationale," Dean said, adding that once NASA engineers agree on that, the space station should be once again clear for spacewalks in U.S. spacesuits.

NASA will broadcast the Harmony node?s move to the tip of the Destiny lab live on NASA TV beginning at 4:30 a.m. EST (0930 GMT). Click here for SPACE.com?s ISS mission updates and NASA TV feed.

• VIDEO: ISS Commander Peggy Whitson Takes Charge
• SPACE.com VIDEO Interplayer: STS-120 Mission Brings 'Harmony' to ISS
• Complete ISS Expedition Coverage