NASA: Spacesuit's Smoky Smell Prompts Spacewalk Ban

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

Theself-imposed ban was prompted by an apparent U.S. spacesuit glitch during aFriday test at NASA's Johnson Space Center in Houston, Texas, space agencyofficials said. It could be lifted as early as this week, clearing the way for astronautsto stage twoplanned spacewalks outside the International Space Station (ISS) next week,they added.

"Sofar, they have not found any evidence of a combustion event, and not found anyhardware damage," NASA spokesperson Brandi Dean told SPACE.comTuesday.

Accordingto a Monday ISS status report, an astronaut smelled a smoke-like smell inside aNASA 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 ExtravehicularMobility Unit (EMU) spacesuits, Dean said.

"Duringthe 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 100percent oxygen environment. "They got the crewmember out of there in lessthan a minute."

NASAimposed a ban on all U.S. spacewalks as a precaution in case Friday's glitchwas a sign of a generic flaw in the agency's spacesuits.

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

Engineershave performed a series of tests on the afflicted spacesuit and examined itshistory to root out the origin of the smoke-like smell. Some possible sourcesinclude the suit's carbon dioxide-scrubbing canister and the off-gassing ofheated materials, though additional analysis is still under way, Dean said.

Spacesuitengineers will present their findings to a mishap investigation board onWednesday, she added.

NASA hopesto clear its U.S. spacesuits for use soon to allow ISS Expedition16 commander Peggy Whitson and flight engineer Dan Tani to step outside thespace station on Nov. 20 and Nov. 24 on a pair of critical spacewalks to attachcooling and power system lines to the Harmony connecting node.

The astronautswill move the node and its recentlyattached shuttle docking port to the front of the station's U.S. Destinylaboratory early Wednesday using the space station's robotic arm.

Any lengthydelays to Expedition 16 crew's planned spacewalks next week could stall analready hefty work schedule to ready the ISS for NASA's planned Dec. 6 launchof 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 stationcrew's schedule to allow Atlantis's STS-122 crew to launch during December'sslim, one-week window.

"Themain thing is getting the flight rationale," Dean said, adding that onceNASA engineers agree on that, the space station should be once again clear for spacewalksin U.S. spacesuits.

NASAwill broadcast the Harmony node?s move to the tip of the Destiny lab live onNASA TV beginning at 4:30 a.m. EST (0930 GMT). Click here for SPACE.com?s ISS mission updatesand 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