This
story was updated at 1:20 a.m. EDT, March 23.
HOUSTON -
Two astronauts floated outside the International Space Station (ISS) Saturday
on a record fifth spacewalk for their mission, this one aimed at transferring a
shuttle inspection boom to the orbiting lab's exterior.
Spacewalkers
Robert Behnken and Mike Foreman used their spacesuit-clad hands to snatch the
shuttle Endeavour's 50-foot (15-meter) sensor-tipped boom from the tip of a
robotic arm and attach it to the station for a later orbiter flight.
"You're a
gladiator," astronaut Rick Linnehan, who choreographed the spacewalk, told Foreman from inside Endeavour after playing a clip from the film "Gladiator" during the six-hour,
two-minute excursion.
The
spacewalkers worked in concert with robotics operators inside Endeavour and the
ISS to move the shuttle's heat shield-scanning boom between the crane-like
appendages of the orbiter, station and the flesh-and-blood arms of the
astronauts themselves.
Endeavour
astronauts used the laser and camera-tipped inspection boom to scan their
shuttle's heat shield just after launch, then
again on Friday, for damage during their planned 16-day spaceflight.
NASA has
launched the 50-foot (15-meter) booms on every shuttle flight since the 2003
Columbia accident to ensure orbiters are safe to land.
But
Endeavour's sister ship Discovery can't carry the tool when it launches May 25
because its cargo, Japan's massive
Kibo laboratory module, fills up the entire payload bay. So that shuttle's
crew will use Endeavour's once they arrive at the space station, mission
managers said.
Behnken and
Foreman attached a vital power cable to the inspection boom to keep its
delicate sensors warm during the two months before Discovery's launch.
They began
their spacewalk - the fifth and last planned for their record12-day stay at the
space station - nearly an hour early at 4:34 p.m. EDT (2034 GMT). The excursion
marked the most ever for a visiting shuttle crew at the space station, though
astronauts have performed five spacewalks on service calls to the Hubble Space
Telescope.
Station's
jinxed joint
With
Endeavour's boom tucked into its new perch, Foreman went on to inspect an
ailing solar array joint on the station's starboard side.
The
massive, 10-foot (3-meter) wide joint is designed to rotate the station's
starboard solar wings like a paddlewheel to track the sun and maximize power
production. But astronauts discovered metal shavings and damage in the joint
last October, and have surveyed it several times during spacewalks to identify
the source.
Foreman
took a close look at an apparent ding discovered during an earlier
inspection.
"I feel
like this is a divot," Foreman said, as he passed a wipe cloth over the area.
"I feel a little roughness as I rub it over there, it doesn't feel like a
protrusion."
Foreman
photographed the divot, as well as the views under several under protective
covers along the joint.
"You're
doing great with that camera, Mike," said ISS flight engineer Garrett Reisman
from inside the station. "We're going to hire you to do my cousin's bar
mitzvah."
ISS flight
director Dana Weigel said Foreman's inspection found no sign of any debris
strike the joint's protective covers, which will allow engineers on Earth to
narrow their search for the damage source and come up with repair options, if
required.
"The first
decision point is going to be the end of March," Weigel said after the
spacewalk, adding that the joint can be moved intermittently for the time
being. "Our current predictions show that we're good for the next couple of
flights."
While Foreman
tackled the joint inspection, Behnken used a hammer to force a stubborn
materials exposure experiment in place outside the station's European-built
Columbus laboratory. Mission Control applauded his efforts and suggested his
nickname be switched from "Bam Bam" to "Thor."
"Alright! Bam Bam, Thor, whatever it takes," Behnken said. "We're
here to serve."
Saturday's
excursion marked the 109th spacewalk outside the ISS and the third career
outings for both Behnken and Foreman.
Behnken ended
the orbital work with 19 hours and 19 minutes of spacewalking time, while
Foreman concluded with 19 hours and 34 minutes. Endeavour's entire spacewalking
team, which included Reisman and astronaut Rick Linnehan, spent a total of 33
hours and 28 minutes working outside the station during their five spacewalks.
Commanded
by veteran shuttle flyer Dominic Gorie, Endeavour's STS-123 crew is in the
homestretch of a packed construction mission. The astronauts have delivered a
new crewmember, Japanese storage module and the Canadian-built
Dextre maintenance robot during their mission.
Endeavour
is slated to undock from the station late Monday and return to Earth Wednesday
evening.
NASA is
broadcasting Endeavour's STS-123 mission live on NASA TV. Click here for SPACE.com's
shuttle mission coverage and NASA TV feed.
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