Japan's science laboratory module added to station
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 3, 2008
"Today we were extremely happy to see the Kibo pressurized module attached at its permanent location," said Tetsuro Yokoyama, deputy manager of the Kibo project for the Japanese space agency.
Floating in the Quest airlock module, the astronauts began repressurizing at 7:10 p.m. to officially end the six-hour 48-minute spacewalk, the first of three planned for the shuttle Discovery's mission.
"You guys did an awful lot of great work today," spacewalk coordinator Kenneth Ham, Discovery's pilot, called from the shuttle. "And it looked like you were having a lot of fun on the way."
"Oh yeah," Garan agreed.
"Nice job, quarterback," Fossum said.
This was the 110th spacewalk devoted to station assembly and maintenance since construction began in 1998, the 11th so far this year, pushing total EVA time to 692 hours and 52 minutes.
"Mike and Ron, it was a pleasure working with you today," astronaut Chris Ferguson radioed from mission control. "Today was the 43rd anniversary of the first U.S. EVA conducted by Ed White on Gemini 4. So I think it was appropriate we had two Air Force guys out the door today in honor of Ed White."
"Well, thank you very much," one spacewalker replied. "Thanks Chris, appreciate that," said the other.
As the spacewalk was winding down, Hoshide, assisted by Karen Nyberg and outgoing station flight engineer Garrett Reisman, were in the final stages of attaching the Kibo - "Hope" - laboratory module to Harmony's left-side port. The module was pulled out of Discovery's cargo bay just before 5 p.m. It took about an hour-and-a-half for the astronauts, operating the station's robot arm, to move the laboratory into place for attachment.
"Congratulations, especially (Japan's) Tsukuba (Space Center)," Hoshide radioed after motor-driven bolts locked the two modules together. "We have a new 'hope' on the international space station."
"It was an amazing day for the international space station program, an amazing day for our partnership," said Kirk Shireman, deputy manager of the space station program at the Johnson Space Center. "We're very pleased to have Kibo, the pressurized module of Kibo, on board the international space station (at) it's final home. It's been an amazing journey for Kibo. It arrived in the United States in May 2003, was launched in May 2008 and now it's at its permanent long-term home on the international space station."
LeRoy Cain, chairman of NASA's Mission Management Team, said analysis of launch and on-orbit imagery is ongoing and that a final verdict on the health of the shuttle's heat shield is not yet possible. But based on what engineers have seen to date, the MMT decided there was no need for a so-called "focused" inspection before Discovery undocks.
So far, Cain said, engineers have identified just four "areas of interest" on the shuttle's belly and all of them are small and no concern for re-entry.
"We're far enough along in our assessments ... to be able to say we don't have any requirement for a focused inspection," he said. "We do have a few areas on the tile we're looking at (but) we essentially cleared the vehicle for emergency deorbit purposes and within a day or two, we'll be able to go further than that. Overall, the performance has just been outstanding."
He said analysis of ascent imagery and close-up photographs taken by the station crew during Discovery's final approach before docking Monday showed that foam debris from the ship's external tank that was seen falling away during launch did not cause any damage to the shuttle's protective tiles."
One of the highlights of today's spacewalk was an inspection of the station's right-side solar alpha rotary joint, or SARJ, and an assessment of various techniques that may be used in the future to clean metallic contamination off the 10-foot-wide drive gear.
The motor-driven gear, which rotates outboard solar arrays to track the sun, is held in place by 12 trundle bearing assemblies that grip the ring on three faces. One of those surfaces has broken down, generating large amounts of metal shavings and debris.
During today's spacewalk, Fossum showed the debris can be cleaned up by applying a layer of grease to the contaminated surface and then using a scraper and wipes to remove it, along with trapped particles.
He also inspected a blemish on a different surface of the drive gear and discovered it is a depression, or pit, and not a buildup of debris as some engineers had hoped. A buildup could, in theory, be removed but a pit indicates a defect in the surface, possibly a starting point for the same type of degradation that generated the debris on the other face.
"We confirmed it was a divot," Shireman said. "Actually, most of us had been expecting that was really what it was because of the two options, that's the worst one. It says that surface has also sustained damage and it will most likely propagate as we continue to operate or rotate that SARJ. It doesn't go to the root cause, but it is another piece of data.
"So we'll factor that into our analysis. Certainly, the imagery we took today we'll use and we'll compare with the photos from (recent) EVAs and we'll determine if this spot is growing and what the rate of propagation is. We are continuing to minimize the amount of rotations on this ring, so we don't think it makes this situation any more grave than it was before. Just some additional data."
NASA managers hope to clean the contaminated drive gear enough to permit at least limited use before eventually switching to an undamaged backup gear. But they want to clean up the contamination before then to prevent any particles from migrating to the other wheel and causing additional damage.