KENNEDY SPACE CENTER, Florida (CNN) -- Engineers on Monday are closely scrutinizing a small crack in insulation on the space shuttle's fuel tank as NASA continues to prepare for a Tuesday launch.
NASA deputy manager John Shannon said the foam that cracked covers a bracket that connects the liquid oxygen feedline to shuttle Discovery's external fuel tank. When engineers went to inspect it, they pinched off a .0057-pound, 3- inch piece of foam. Even so, Shannon said, had that piece fallen off during launch it wouldn't have damaged the orbiter. The crack was discovered during an inspection Sunday evening, and is 4- to 5-inches- long and an eighth- to a quarter-inch wide, NASA said. (Watch CNN's space expert explain when and why the crack could have appeared -- 1:27) The Mission Management Team met Monday morning to go over possible scenarios -- including a possible fix. Team members will meet again Monday evening to decide whether it must be fixed and whether the shuttle can launch Tuesday at 2:38 p.m. ET. "We're going to meet back again at 6:30 p.m. ET tonight and summarize where we are with the analysis, summarize where we are with the inspection, try and and clear all our concerns and go launch tomorrow," Shannon said. NASA has until July 19 to attempt a launch. If a repair is needed, NASA would have to build a platform that would reach out to the bracket, which would allow engineers to make the fix, according to NASA spokesman Bruce Buckingham. That would take more than a day, and delay Tuesday's launch. But Buckingham says there's no fear the July 19 window would be in jeopardy. There are two concerns with the cracked foam -- it could fall off during launch, and the piece is close to the belly of the orbiter. The second concern -- ice could form in the crack, causing it to expand or the ice chunk to fall. In 2003, a 1.6-pound piece of insulating foam broke loose from shuttle Columbia's external tank during its launch and fatally damaged the wing, an accident investigation board concluded. The spacecraft broke up when superheated gases entered the damaged wing upon re-entry into the atmosphere. NASA spent nearly 30 months redesigning the tank. NASA postponed the launch of the shuttle on Saturday and Sunday because of bad weather. Weather conditions for Tuesday give NASA a 60 percent chance of launching. Those odds drop to 40 percent on Wednesday, according to U.S. Air Force 1st Lt. Kaleb Nordgren. A launch Tuesday would be the first time a shuttle has taken off on the Fourth of July. No launch attempt was scheduled for Monday because the weather forecast was even worse, and because NASA needed time to top off the fuel cells that provide power while the shuttle is in orbit. NASA can keep trying until July 19. If the launch hasn't happened by then, the next window for the mission will open in late August. Those windows of opportunity are determined by the path of the orbiting international space station, the shuttle's destination. With each passing day, the time for a launch gets earlier by 22-1/2 minutes. That could be good news for NASA because summer thunderstorms are less likely to be a problem earlier in the day. Plans call for a 12-day mission to deliver supplies to the space station and drop off European Space Agency astronaut Thomas Reiter, who will join the Expedition 13 crew members already there. Two astronauts, Piers Sellers and Mike Fossum, will conduct two spacewalks, to test a new shuttle robotic arm and to repair a damaged piece of equipment outside the space station. They might also do a third spacewalk, to test repair techniques on the shuttle's thermal protection system. (Watch as the seven astronauts head to the shuttle -- 5:22) Safety concerns NASA's decision to resume shuttle flights this summer is not without controversy. In the weeks leading up to the launch, two NASA officials, chief engineer Chris Scolese and chief safety officer Bryan O'Connor, gave a "no go" for the launch. This launch would be only the second shuttle flight since Columbia disintegrated during re-entry in 2003, killing all seven astronauts on board. Program manager Wayne Hale said NASA engineers have learned a lot about foam dynamics in the past year, but there is no way to stop the foam from flying off the tank. "Foam will come off. There's no way around that. It is an expected event," said John Chapman, NASA's external tank project manager. "Our objective is to make sure if it does come off, it comes off in small enough pieces that it doesn't cause any harm." O'Connor and Scolese are specifically concerned about three dozen pieces of foam on Discovery's external fuel tank known as ice-frost ramps. (Watch as O'Connor and Scolese explain why they are "no go" for launch -- 2:31) Small pieces of foam have come off the ice-frost ramps on previous flights. And in a worst-case scenario, small pieces of foam debris could cause critical damage to the orbiter, according to wind tunnel test results conducted by NASA this spring. Even so, NASA officials have put off structural modifications until after the launch. Disagreements good NASA Administrator Michael Griffin called the disagreements with the repairs a good sign that the culture at NASA has changed. The agency was faulted by the Columbia investigation board with having a conformity of opinion. (Watch as astronaut Scott Kelly explains why risk is a part of spaceflight -- 5:05) "I personally want every engineer to express the best opinion that they can give us," Griffin said. He and top senior officials took into consideration O'Connor and Scolese's concerns but concluded that if falling foam damages Discovery, engineers will know about it, and the crew can take refuge on the space station and wait for a rescue mission. Griffin said he wants to fly now because the shuttle program is slated to end in 2010 and NASA is committed to flying at least 16 missions to complete the space station. He said he worries that delays now will lead to dangerous schedule pressure later. "I very strongly feel that we are not risking crew for foam in this case, or I won't feel comfortable launching," he said. Lindsey, the commander, said he and his crew understand the risks and are ready to fly. "We've been training for an awfully long time," Lindsey said. "We're as prepared as we're ever going to be." Reply with a "Thank you" if you liked this post. _____________________________ MEDIANEWS mailing list medianews@twiar.org To unsubscribe send an email to: [EMAIL PROTECTED]
