Fourth spacewalk ruled out
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: August 4, 2005
NASA's mission management team today ruled out another shuttle repair spacewalk, this one to fix a damaged insulation blanket, saying a detailed analysis showed Discovery's crew can safely return to Earth as is.
"We have good news," astronaut Julie Payette radioed from mission control a few minutes past 1 p.m. "The MMT just got to the conclusion that the blanket underneath (the commander's) window is safe for return. There is no issue."
Concern about the damaged 20-inch-long, 4-inch-wide insulation blanket just below Discovery commander Eileen Collins' left cockpit window was the only remaining question mark about the shuttle's condition prior to re-entry and landing Monday at the Kennedy Space Center. Engineers earlier cleared the shuttle's heat-shield tiles and wing leading edge panels after an impromptu repair job Wednesday in which two protruding "gap fillers" were plucked from the ship's belly during the crew's third, and now final, spacewalk.
The blanket in question forms an interface of sorts between heat-shield tiles surrounding the cockpit windows and thermal insulation blankets that protect much of the shuttle's upper fuselage.
Engineers concluded earlier that the damaged blanket posed no threat during the high-speed, high-heating parts of re-entry. Rather, the concern was that the top layer of the blanket could rip away at lower velocities, when the shuttle has fallen into the thicker regions of the atmosphere, fly back and impact the back end of the space shuttle.
Deliberately damaged blankets similar to the one aboard Discovery were tested overnight in a wind tunnel at NASA's Ames Research Center in California to help engineers and aerodynamicists calculate when during entry debris might rip away, what sort of trajectory it might follow and whether an impact could cause serious damage to the shuttle's rear wing elevons, rudder/speed brake or aft rocket pods.
But the wind tunnel tests, along with additional analyses, showed the blanket posed no significant threat to Discovery's return to Earth.
"We have new analysis that shows debris transport would be no issue and we came to the same conclusion with the Ames (wind) tunnel tests," Payette told the crew today. "So basically, no EVA 4 (fourth spacewalk)."
"Thanks, no EVA 4," Japanese astronaut Soichi Noguchi replied from orbit. "That's, I would say, good news."
In Crawford, Texas, President Bush today praised the crew's repair work Wednesday, saying "like a lot of Americans, I was amazed at the procedures that took place to repair the craft. It was pretty remarkable."
"I believe that the mission is important," he said. "And I know that the mission directors will make the right decision about how to proceed. Ours is a country that values the safety of our citizens, particularly those we ask to take risks in space. And there will be a lot of deliberation, a lot of thought, that goes into the decision as to whether or not those brave souls should return on that vehicle."
Earlier today, the Discovery astronauts and their colleagues aboard the international space station paid tribute today to the 21 astronauts and cosmonauts who lost their lives in spacecraft mishaps, saying the benefits of space travel outweigh the risks and that America "must not be bridled by timidity."
Taking turns reading prepared scripts while downlinking video of a long pass across the Indian Ocean, the combined shuttle-station crews remembered the crews of Columbia, Challenger, Soyuz 1 and 11 and the Apollo 1 victims of a launch pad fire that forced NASA to redesign its Apollo moonships.
"Certainly, space exploration is not easy and there has been a human price that has been paid," said Wendy Lawrence. "As we step out into these new frontiers, we find that it is very unforgiving of our mistakes. The lives lost over 30 years ago with the earliest steps taken by the crews of Apollo 1, Soyuz 1 and Soyuz 11 showed us that and after, the crew of Challenger reaffirmed the need to be ever vigilant of the risk."
Charles Camarda then took over, saying "tragically, two years ago we came once more to realize that we had let our guard down. We became lost in our own hubris and learned once more the terrible price that must be paid for our failures."
"In that accident, we not only lost seven colleagues, we lost seven friends. Their families never shared any homecoming. Those seven were driven by the fire of the human spirit within, they believed in space exploration, they knew the risks, but they believed in what they were doing. They showed us that the power of the human spirit is insatiable. They knew that in order for a great people to do great things, they must not be bridled by timidity."
"To the crew of Columbia, as well as the crews of Challenger, Apollo 1, and Soyuz 1 and 11, and to those who have courageously given so much, we now offer our enduring thanks," said Discovery pilot James Kelly. "From you, we will carry the human spirit out into space and we will continue the explorations you have begun. We will find those new harbors that lie out in the stars of which you dreamed.
"We do this not just because we owe it to you, but we do it because we also share your dream of a better world. We share your dream of coming to understand ourselves and our place in this universe. And as we journey into space you will be in our thoughts and will be deeply missed."
Collins closed the brief memorial with a verse from Laurence Binyon's poem, "For the Fallen:
They shall grow not old, as we that are left grow old;For the record, here's a list of the 21 men and women who have lost their lives in spacecraft accidents:
"For the risk-averse, the only acceptable thing to do now is retire the shuttle program immediately and wait for the divine arrival of the next generation of spacecraft," he wrote. "I am disgusted at the lack of courage and common sense this attitude shows.
"All progress involves risk. Risk is essential to fuel the economic engine of our nation. And risk is essential to renew America's fundamental spirit of discovery so we remain competitive with the rest of the world."
Kranz said Discovery's flight has been "remarkably successful" so far, despite the unexpected release of a large piece of foam insulation during launch. Overall, Kranz said, the shuttle tank shed 80 percent less foam than previous missions and "only in the news media, apparently, is an 80 percent improvement considered a failure. Rather than quit, we must now try to reduce even more the amount of foam that comes off the tank."
"There are many nations that wish to surpass us in space," he wrote. "Does the 'quit now' crowd really believe that abandoning the shuttle and the international space station is the way to keep America the pre-eminent space-fairing nation? Do they really believe that a new spacecraft will come without an engineering challenge or a human toll? The path the naysayers suggest is so out of touch with the American character of perseverance, hard work and discovery that they don't even realize the danger in which they are putting future astronauts - not to mention our nation."
President Bush did not directly address the risks of spaceflight, but he made it clear he believes his new moon/Mars initiative will reinvigorate the space program.
"It is important for our fellow citizens to understand that we're going to take the NASA mission beyond the current mission," he said. "The plan right now is to phase out the shuttle by 2010 and then begin to put a strategy in place that will use the moon as a launching spot for further exploration. ... The people I've talked to inside NASA are excited about the mission, the reinvigoration of the vision of exploration.
"And I appreciate the administrator (Michael Griffin) working on getting that strategy in place so that when the decision is made to finally get rid of this phase of exploration we'll be ready to take on the new phase. That's important for the American people to understand, that, one, exploration is important. Two, there'll be some good coming out of exploration. And three, that we've got a new vision embraced by NASA and its pioneers."
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