Two
astronauts aboard the International Space Station (ISS) are going through the
motions of a spacewalk today in preparations for the real thing later this
week.
ISS
Expedition 13 commander Pavel
Vinogradov and flight engineer Jeffrey
Williams donned their Russian-built Orlan spacesuits
Tuesday for a dress rehearsal of the nearly six-hour June 1 excursion to maintain
their orbital spacecraft.
"The crew
seems very comfortable and ready to go do the spacewalk," said Holly Ridings, NASA's
lead flight director for the upcoming extravehicular activity (EVA), during a Tuesday press briefing
at the Johnson Space Center in Houston, Texas.
While NASA
ISS flight controllers detailed the Expedition 13 crew's coming spacewalk, the
astronauts themselves conducted final checks on the systems and mobility of
their Orlan spacesuits, NASA officials said.
Vinogradov
and Williams are expected to exit the space station's Russian-built Pirs
docking compartment at 6:40 p.m. EDT (2240 GMT) for a five-hour and 40-minute
spacewalk to gather experiments and maintain the ISS. The spacewalk will mark
the sixth career EVA for Vinogradov - who staged five
others from Russia's Mir space station - and the second for Williams.
"The equipment
that we have is very good and the training that we've been provided by the team
on the ground is very good," Williams told reporters last week. "We will be
very prepared when the time comes to go out the door."
Two key
tasks
Among the two
vital tasks for Thursday's spacewalk is the planned installation of a new vent for
the space station's primary oxygen generator - known as Elektron - to dump
waste hydrogen into space.
The Elektron
device, which separates water into much needed oxygen and waste hydrogen,
has endured months of finicky activity largely due to a leak
last year that contaminated its original vent valve and rendered it
unusable, said Kirk Shireman, NASA's ISS deputy program manager, during the
press briefing.
Since then,
the Elektron has shared a vent with another ISS system, shutting down as the
vent's original user required and undergoing shaky restarts. Vinogradov is
expected to install a new vent that would once again give the Elektron a
dedicated line to dump excess hydrogen.
"After this
EVA, you'll see very few blips in this Elektron system," Shireman said.
Vinogradov
and Williams will also replace a faulty camera aboard the Mobile Base
Transporter, which slides the space station's robotic arm and other large ISS
components along rails that run the length of the orbital laboratory's main
truss. While the camera itself isn't required for future ISS construction, the failure
of another camera could cause serious delay, NASA officials said.
"If we didn't
do this [camera replacement] and had an additional failure, we might
conceivably have to stop station assembly for awhile," Shireman said.
The next
ISS construction mission - STS-115 slated to launch aboard the Atlantis shuttle
in late August - will deliver a new solar array and truss to the ISS, he added.
The
Expedition 13 crew will also retrieve a series of experiments attached to the
ISS exterior, including one that studies the effects of Russian thrusters on
the station's hull and a Biorisk canister to determine how the space
environment affects microorganisms. Vinogradov is due to photograph one antenna
and remove slack from the cable of another at the aft end of the station's
Zvezda module.
Orbital
golf rescheduled
Missing
among the Expedition 13 crew's task roster is a golf shot
for which Vinogradov had trained to perform as part of a commercial stunt for
the Canadian golf equipment firm Element 21.
Scheduled under
an agreement between Toronto-based Element 21 and Russia's Federal Space
Agency, the golf shot called for Vinogradov to smack a radio
transmitter-equipped golf ball into orbit with a gold-plated six iron (both
made by Canadian golfing firm). But the Canadian sporting good firm agreed to put
off the event until November when Russian ISS officials required more work time
for its spacewalks, company officials said.
"We figured
that it was important for them and we could delay our space shot," Element 21's
president and CEO Nataliya Hearn told SPACE.com, adding that Russian
flight controllers said they needed more time to perform ISS repairs. "We're fairly
happy, because it's obvious that the space shot is going ahead."
The golf
shot is now slated for a Russian spacewalk during the next ISS mission - Expedition
14 - with cosmonaut Mikhail Tyurin wielding the club.
NASA
officials said the final safety review documentation is still being finalized
to ensure that the golf stunt will not pose a debris hazard for the ISS or space
shuttles.
Hearn said that
she hopes that the golf shot - video of which will be used in a future Element
21 commercial - could eventually lead to an orbital driving range of sorts for
astronauts, or even space tourists, in coming years.
"The women
would be aiming for Venus and the men will be aiming for Mars," Hearn said.
NASA will
provide live coverage of the Expedition 13 crew's spacewalk on NASA
TV beginning at 5:30 p.m. EDT (2130 GMT) on June 1. You are invited to
follow the crew's progress using SPACE.com's NASA TV feed by clicking here.
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