HOUSTON -- Two spacewalking astronauts partially furled an
old solar wing outside the International Space Station (ISS) Wednesday, then
faced down tough bolts and crossed wires to help prime the outpost's newest
arrays to track the Sun.
Atlantis
shuttle astronauts Patrick Forrester and Steven Swanson began their seven-hour,
15-minute spacewalk poking, prodding and fluffing the nearly seven-year-old solar array partway back into its
storage boxes before moving on to other tasks.
"We were
able to get to about just-not-halfway retracted," said Kelly Beck, NASA's lead
ISS flight director for the STS-117 mission.
The
remaining portion of the 115-foot
(35-meter) solar array, which reaches starboard from the station's
tower-like Port 6 (P6) truss, will be retracted during a later extravehicular
activity (EVA) by Atlantis' STS-117 crew.
"Pat and Steve left them in a
nice [configuration] for EVA attempts later on," said Atlantis' STS-117
commander Rick Sturckow.
Forrester and Swanson used a set
of improvised tools - including
a so-called "hockey stick" named for its shape - wrapped in translucent
orange Kapton tape to free stuck grommets, snip off loose spring leaders and
feather the P6 solar panels so that they would retract properly.
"Now this
is a view to remember right here," said Forrester, who handled the tools while
perched at the end of the station's robotic arm.
Mission managers have already
set aside more time later in the STS-117 crew's mission to complete the solar
array retraction, with additional efforts set for Thursday and during a Friday
spacewalk.
"It was always the plan to
give us several days to retract the arrays," said Mike Suffredini, NASA's ISS
program manager, after the spacewalk.
During Wednesday's EVA, shuttle
managers also decide to add an anticipated Atlantis heat
shield blanket repair to the docket of the STS-117 crew's Friday spacewalk.
A corner of the blanket pulled free of its position on Atlantis' left
aft-mounted Orbital Maneuvering System (OMS) during the shuttle's June 8
launch.
Forrester and Swanson began their
spacewalk from the station's Quest airlock at 2:28 p.m. EDT (1828 GMT), about
20 minutes later than planned, due to communication difficulties between
themselves and crewmates aboard Atlantis helping to choreograph their work. The
spacewalk also ran longer than the initially planned 6.5 hours, leaving the
astronauts a bit low on some spacesuit supplies by the excursion's end.
Near-ready to rotate
By the end of today's spacewalk,
astronauts and flight controllers reeled in the P6 solar array enough to allow
the station's new
starboard solar wings to rotate and track the Sun, but spacewalkers found
an apparent wiring mix-up with two gears to drive that rotation.
Forrester encountered the wiring
error as he installed a Drive Lock Assembly gear to drive a 2,500-pound
(1,133-kilogram) Solar Alpha Rotary Joint (SARJ) to rotate the station's new Starboard
4 truss and its two solar wings like a Ferris wheel to track the Sun. The
gear is one of two that drive the SARJ's rotation.
"It looks like the wires were
crossed," NASA astronaut Megan McArthur, serving as spacecraft communicator in
Mission Control here at the Johnson Space Center, told the spacewalkers after
some tests by flight controllers found commands meant for one gear were going
to its counterpart.
The hardware was later installed
successfully, though more work on a later spacewalk will be required to repeat
the fix on the second SARJ gear.
To keep the SARJ from rotating,
Forrester and Swanson left a one of a series of launch locks in place to secure
it. They also loosened the torque on a series of launch restraint bolts that
will now be removed on a later spacewalk. The locks and restraints secured the
SARJ and S3/S4 truss inside Atlantis' payload bay during its June 8 liftoff and
are no longer needed.
Wednesday's EVA marked the
second of four planned for the STS-117 mission, the 85th dedicated
to space station construction or maintenance, and the 57th originate
from the ISS itself.
The spacewalk also marked the
first career EVA for Swanson and the third for Forrester.
"Thanks to the help from you and
the ground," Forrester told his crewmates. "That was wonderful."
NASA is
broadcasting the space shuttle Atlantis' STS-117 mission live on NASA TV. Click here for mission updates and
SPACE.com's video feed.
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