American
astronaut Sunita Williams will return home from her mission to the
International Space Station (ISS) a bit early this summer due to delays associated with
NASA's next shuttle flight, the space agency announced Thursday.
Williams,
an ISS Expedition 15 flight engineer, is now set to return to Earth in June
aboard the space shuttle Atlantis following an 11-day assembly mission by the
orbiter's STS-117 astronaut crew. Her replacement, NASA astronaut Clayton
Anderson, will join the STS-117 crew roster as a late addition, NASA officials
said.
"Since
an earlier crew rotation was possible, NASA managers decided it would be
prudent to return Williams and deliver Anderson sooner rather than later," the
space agency said Thursday.
Williams,
41, first arrived at the ISS in December 2006 during its then-Expedition 14
mission and stayed on this month for the beginning of Expedition 15. She and
Anderson were
initially expected to swap places during NASA's STS-118 shuttle flight aboard
the shuttle Endeavour in late June.
But
that mission was rescheduled to no earlier than Aug. 9 following a string of
delays caused by hail-spawned fuel tank damage that prevented an initial March
15 launch of Atlantis' STS-117 mission. Atlantis is now set
to launch towards the ISS no earlier than June 8.
A
U.S. Navy commander making her first spaceflight, Williams has repeatedly said
that she was prepared to return home early or late depending on what ISS mission
managers saw as the best move for the station. Earlier today, she told reporters
that she and her family had weathered similar experiences during her long
deployments abroad with the Navy.
"It
comes with the job, you just need to be flexible," Williams told USA Today
Thursday in a space-to-ground video link. "It's an operational ship, and an operational station and we
just need to take care of it the right way and do the right things for the
program."
While Williams
is returning to Earth on an earlier shuttle flight, she will be spending about the
same amount of time in space - just over six months - as originally planned, NASA spokesperson Kylie Clem told SPACE.com Thursday.
Mission
tweaking
Returning
Williams to Earth in June does add some additional complexity to an already
tricky space station construction flight.
Commanded
by veteran NASA shuttle flyer Rick Sturckow, Atlantis' now seven-astronaut STS-117
crew will
deliver a 17.5-ton pair of new starboard trusses and solar arrays to the ISS.
The mission was delayed to June 8 after a freak storm over Atlantis' launch pad
gouged thousands of dings into the orbiter's foam-covered external fuel tank in
late February, prompting repairs.
Adding
the ISS astronaut crew swap to the mission requires extra cargo - in the form
of Anderson's supplies - and handover activities to an already busy flight.
"When you
rotate a crewmember, there's a significant amount of upmass in addition to that
particular crewmember," Kirk Shireman, NASA's deputy ISS program manager at the
agency's Houston-based Johnson Space Center, said last month. "There's their
equipment, their [spacesuit], they have to have a special seat to fly home on
the Soyuz...adding that additional mass is a hit, and adding handover activities
is a timeline hit."
But
after a detailed review Thursday morning, ISS mission managers decided they
could in fact include the Expedition 15 astronaut crew swap during the STS-117
mission with no impact to shuttle of station mission objectives, Clem said.
Clayton,
a 48-year-old native of Omaha, Nebraska, will make his first spaceflight during
Expedition 15 and was slated to participate in the spacewalks planned for the
STS-118 mission.
"He
will continue to train for that because he will still be on station," Clem said.
Female spaceflight records
Waiting
until August's STS-118 mission would have extended Williams' spaceflight by at
least one month and given her the U.S. record for longest continuous
spaceflight, which is currently held by her former crewmate - Expedition
commander Michael Lopez-Alegria - who
spent 215 days in orbit before returning to Earth on April 21.
Instead,
Williams will return to Earth no earlier than June 19 after turning her
Expedition 15 duties over to Anderson. Anderson, in turn, will be replaced by
NASA astronaut Daniel Tani during the planned STS-120 shuttle mission to launch
no earlier than Oct. 20. She currently holds the title for most spacewalks and
spacewalking time - 29 hours and 17 minutes over four excursions - for a female
astronaut.
Clem
said Williams is now expected to spend about 192 days in space by her mission's
end, which would set a new record for the longest single spaceflight by a
female astronaut.
The
current single-mission record by a female spaceflyer is held by NASA astronaut
Shannon Lucid, who spent 188 days in orbit during a 1996 mission to Russia's
Space Station Mir.
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