NASA examines pictures of shuttle's heat shield Astronauts unload cargo, mission extended by one day
http://www.cnn.com/2006/TECH/space/07/07/space.shuttle.ap/index.html NASA examines pictures of shuttle's heat shield CAPE CANAVERAL, Florida (AP) -- NASA engineers examined new detailed pictures of space shuttle Discovery's heat shield Friday, a day before two astronauts were to embark on the most disorienting task of their 13-day mission: a wobbly spacewalk. Astronauts Piers Sellers and Michael Fossum will make a six-and-a-half-hour spacewalk Saturday that is the cosmic equivalent of trying to paint a house while standing on a rickety ladder. They will stand at the end of the shuttle's 100-foot robotic arm and extended boom to test a technique for repairing the spacecraft's heat shield. "You're standing at the end of it at night, so you'll feel like you're standing on a diving board or standing at the top of a telephone pole or hanging down from a ceiling," Sellers said in a June interview. "It's disorienting, there's no question." 'Hot potato' And if that's not enough, mission control told Sellers and Fossum that they may also have to play "hot potato" with a potentially scorching replacement part for a broken transporter on the international space station. The railcar-like device must be fixed to help with future construction of the orbital outpost. If the part gets too hot "let it hang from a tether or 'hot potato' it between your hands," mission control said. Also Friday, NASA managers announced that Discovery has enough fuel to stay up for a 13th day to squeeze in a third spacewalk for Sellers and Fossum on July 12. In that bonus spacewalk, Sellers and Fossum will practice shuttle thermal repairs and perhaps conduct a real fix by yanking out spare gap filler between heat-shield tiles just below the shuttle's nose. Gap filler is material fitted between tiles to prevent them from rubbing against each other. Two pieces of gap filler had to be removed from Discovery's belly during a spacewalk last year because of concerns they would cause problems during re-entry. Early photos showed that the gap filler may be sticking out 0.4 of an inch, and anything more than 0.25 of an inch is unacceptable, lead flight director Tony Ceccacci said Friday. However, the early photos could be off by as much as one-third of an inch, he said. The gap filler was one of two potential heat shield problems that arose Friday. Astronauts spent several hours focusing the cameras on six specific "areas of interest" on the shuttle that had been seen in earlier photographs. Engineers need more information about the heat shield to ensure there is no damage like the kind that doomed Columbia's flight in 2003. Besides the gap filler, NASA is concerned about a white spot on the shuttle's nose cap that engineers have described to the crew as resembling bird droppings -- but not the same as white splotches found earlier on the wing. The concern is that the spot could be a hole in the thermal-protection system and need repair, Ceccacci said. By Friday afternoon, it was too early to tell if these were serious problems, but NASA managers were optimistic. Spacecraft communicator Lee Archambault told Discovery's crew that early assessments of the photographs were promising. The crew spent much of Friday hauling thousands of pounds of supplies into the station. Unloading items 220 miles above Earth was a challenge because of the lack of gravity, according to Discovery commander Steve Lindsey. "You've got to go very, very slow because if you go fast, you kind of run into things and bump into other equipment," Lindsey said in interviews with reporters on the ground. "It's kind of an interesting choreography we have to go through." Gregory S. Williams [EMAIL PROTECTED] Reply with a "Thank you" if you liked this post. _____________________________ MEDIANEWS mailing list [email protected] To unsubscribe send an email to: [EMAIL PROTECTED]
