Astronaut Mike Fossum, lead spacewalker for STS-124, rehearses plans for work outside the International Space Station. He is wearing a NASA Extravehicular Mobility Unit, or EMU spacesuit.
HOUSTON — Astronauts are preparing to venture outside of the International Space Station (ISS) later today to install its new Japanese laboratory and attempt to clean grit out of a gummed up solar wing joint.
Spacewalkers Mike Fossum and Ron Garan are preparing to suit up and head outside at 11:32 a.m. EDT (1532 GMT) today, or earlier, if they get ahead of schedule. They have been camping out since Monday night in the station’s Quest airlock to prepare today’s excursion, the first of three planned during their STS-124 construction flight to the ISS.
“It’s one big happy spaceship now,” said Matt Abbott, lead flight director for Discovery’s mission Monday shortly after the shuttle arrived at the station. “It’s great to have the Kibo pressurized module part of the International Space Station. All we have to do now is to install it tomorrow.”
Discovery’s seven astronauts are delivering a new crewmember to the station along with its the newest and largest addition — the tour bus-sized main room of the Japanese-built Kibo laboratory.
The two spacewalkers - Fossum a veteran spacewalker and Garan a first-timer in space — plan to spend about seven hours outside the station. Fossum, the lead spacewalker, will be identifiable as the one wearing a spacesuit with red stripes.
“Our biggest task on EVA 1, our first spacewalk, is really preparing the space station to receive the Japanese module,” Fossum said in a preflight NASA interview. “There’s some covers and launch locks we have to pull off... All these things have to be done manually and so really we’re the blue collar help.”
By the end of the spacewalk the new room should be moved out of Discovery’s payload bay and attached to its new perch on the station.
But before Fossum and Garan can deliver Kibo, the spacewalkers must first retrieve a vital sensor-tipped heat shield inspection boom, which was left for them by a previous shuttle crew because Discovery’s payload bay was too full with the massive Kibo lab to fit the extra 50-foot (15-meter) pole.
The astronauts also plan to inspect the damage on the station’s clogged solar wing joint, and test tools and techniques for cleaning out the debris lodged inside it.
Known as a Solar Alpha Array Rotary Joint (SARJ), the massive gear is designed to rotate the station’s outboard solar wings like a paddlewheel to keep them facing the sun to maximize power generation. But the starboard gear has been hobbled by metallic grit, which has damaged its rotating ring and caused odd power spikes and vibrations that were first detected last October.
From inside the space station, STS-124 pilot Ken Ham will serve as the spacewalk choreographer, instructing the two men outside and making sure they stay on track.
“My role in that team is to be the person on the inside of the shuttle that helps conduct the spacewalk in a real time sense,” Ham said before the flight. “That, I’ve learned over the last few months, is a really fun, rewarding job. It’s a chance to be flexible and use the assets you have in real time to try to coordinate getting a maximum amount of efficiency out of Mike and Ron.”
Mission specialists Karen Nyberg, Akihiko Hoshide and Greg Chamitoff will also be helping out from inside the ISS by operating the space station and shuttle robotic arms. Later in the mission after Kibo’s arm is deployed, Nyberg is expected to become the first person to operate three different robotic arms in space.
This spacewalk will also be a trial run for a new fix on the gloves spacewalkers wear, designed to prevent the tearing near the thumbs seen on recent missions. Both spacewalkers will wear gloves with reinforced patches of a fabric called TurtleSkin on the thumb and index finger. Tests show this material resisting cuts four times better than the normal fabric.
All in all, it should be a busy day for the whole crew.
“We’ve got a lot of work to do,” Garan said before the launch. “It’s a very, very challenging set of spacewalks that we’re doing.”
Though it may be tough, Garan said he is excited for his first taste of space outside the protective walls of the station.
“I anticipate that it will be very overwhelming,” he said. “The view, just the fact that this whole massive station is out there in front of you. We’ve trained it in the pool but it’s just not the same.”
Today’s spacewalk will also mark the 43rd anniversary of the first U.S. spacewalk, performed by NASA astronaut Ed White during the Gemini 4 mission on June 3, 1965.
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