NASA lifted
a brief ban on U.S. spacewalks outside the International Space Station (ISS) Thursday
after engineers cleared the orbital laboratory's spacesuits of potential
fire-hazards, space agency officials said.
The
decision allows ISS Expedition 16 commander
Peggy Whitson and flight engineer Dan Tani to proceed with preparations for
two critical spacewalks next week to continue space station construction.
NASA temporarily
suspended U.S. spacewalks earlier this week after an astronaut smelled
smoke inside a U.S. spacesuit - known as an Extravehicular
Mobility Unit (EMU) - during a ground test at the agency's Johnson Space
Center (JSC) in Houston, Texas. The ban was largely a precaution in case the
incident was due to a generic flaw in NASA spacesuits.
"They had
overwhelming data that showed there was no evidence of a combustion event,"
NASA spokesperson Lynette Madison, of JSC, told SPACE.com.
While
engineers have not completely identified root cause of the Earth-based suit's
smoky odor, the leading candidate is the specific canister used to sift carbon
dioxide from the EMU's 100 percent oxygen interior, she added.
But
engineers were able to clear the spacesuits to be used by Whitson and Tani
during their planned Nov. 20 and Nov. 24 spacewalks of any concerns.
"The EMUs have the go for spacewalk use," stated
an ISS Expedition 16 status report issued today. Because of the high flammability of
a spacesuit's oxygen-rich atmosphere, NASA takes any hint of smoke or
combustion seriously to ensure the safety of spacewalking astronauts.
Whitson and
Tani recharged the water supplies for their EMUs while working aboard the space
station earlier today. Two cooling system radiators were also deployed outside
the ISS. The Expedition 16 crew plans to outfit the station's recently installed
Harmony module with cooling and power lines during the upcoming spacewalks,
which will cap a busy month of work to
move the school bus-sized connecting node to its final perch at the
front of the outpost's U.S. Destiny laboratory.
Madison
said NASA also approved plans today to go ahead with a series of spacewalks scheduled
for December's STS-122 shuttle mission to attach the European-built Columbus
laboratory to one of Harmony's multiple docking ports. The Italian-built
Harmony node is designed to serve as the anchor for European and Japanese
laboratories at the ISS.
Commanded
by veteran shuttle astronaut Stephen Frick, the seven STS-122 astronauts are
slated to launch toward the ISS aboard the Atlantis orbiter on Dec. 6 to begin
their 11-day construction mission.
A preliminary
meeting found the mission to be on track for its December launch earlier this
week, with a final flight readiness review set for Nov. 30, NASA spokesperson
Kyle Herring said.
NASA will broadcast the Expedition 16 crew's second spacewalk outside the
ISS live on NASA TV on Nov. 20 beginning at 5:00 a.m. EST (1000 GMT). Click here for SPACE.com's ISS
mission updates and NASA TV feed.
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