HOUSTON - Flight controllers for the space shuttle Discovery are lauding today's morning spacewalk and its successful repair of the orbiter's heat shield.
During the six-hour spacewalk, Discovery's STS-114 mission specialist Stephen Robinson rode a robotic arm under the orbiter's tile-lined belly and used his fingers to pluck two strips filler material poking out from the spacecraft. The fix all but cleared the shuttle's heat shield for reentry through the Earth's atmosphere next week.
"This was the last thing remaining for us to clear," said Paul Hill, lead shuttle flight director for STS-114, during a mission status report here at Johnson Space Center. "So we have a clean vehicle, pending the blanket discussion."
Engineers are still examining a damaged thermal blanket puffing out below the shuttle commander's window, and just above the 'D' in Discovery along the orbiter's left side. While the blanket has been cleared for landing from a heating perspective, engineers want to ensure it won't rip off during descent and strike some aft portion of the orbiter.
The results of those studies will be presented to Discovery's Mission Management Team (MMT) by Thursday at the latest, shuttle officials said.
In the meantime, spacewalk planners are drawing up contingency plans for a potential fourth spacewalk should mission managers decide the blanket does pose a problem and needs to be removed entirely or merely slashed to ventilate it during reentry, they added.
Regarding today's extravehicular activity (EVA), spacewalk planners said Robinson's repair job--which was watched over by his spacewalking partner Soichi Noguchi outside and their crewmate Andrew Thomas inside the orbiter--went just about as well as they could expect.
"It did turn out to be as easy as we thought it would be," said Cindy Begley, lead EVA officer for Discovery's STS-114 flight. "We proved that we can get access to the bottom of the vehicle, we just never needed to before. Luckily, none of our other contingency plans were required."
Perched atop the International Space Station's (ISS) robotic arm, Robinson carried forceps, scissors and a bent hacksaw to cut off the offending gap-fillers should they prove too unyielding to the human touch, and was prepared to repair any damage he accidentally inflicted on the shuttle's fragile tile surface.
Hill said he felt a wave of relief once Robinson retrieved the second strip and was backing away from the orbiter.
"It was a huge relief, like a feeling that it's all downhill from here," he said.
The repair also proved without a doubt that shuttle astronauts can service the underside of their vehicles, which is desirable not only for gap-filler fixes, but also to manually close doors that house the shuttle's connections to its external tank, "something that was highly desirable for us from the beginning of the [shuttle] program," Hill said.
Throughout the entire repair, Robinson's helmet camera broadcast stunning views of Discovery's tile-covered belly--which he called "a work of art"--and gave flight controllers they're first views of the shuttle's belly with the entire ISS hovering above it.
"We've never seen this before...this was just amazing view for me," Begley said. "The only time we've ever seen full pictures of the space station are when the shuttle is approaching station or flying around [it]."
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