NASA on Wednesday put off a planned fourth spacewalk for the space shuttle Endeavour crew as officials said they had not decided whether to repair a gouge in the ship's heat shield.
While the US space agency studied the 3-inch-by-2-inch gash in Endeavour's belly, a spacewalking astronaut on Wednesday had to go back inside after finding a hole in his glove during work outside the International Space Station.
The fourth spacewalk, which includes other tasks besides the possible repair, had been scheduled for Friday but now will take place on Saturday, NASA said.
Mission management team chairman John Shannon said more tests were being run on damage mockups, but analysis so far "showed there would be no danger at all to the underlying structure" if Endeavour returned to Earth without the repair.
He said he expected a decision Thursday whether to do the repair, after the additional tests were finished.
"I am cautiously optimistic that repair will not be needed," Shannon said.
The gash occurred when insulating foam from the shuttle fuel tank struck Endeavour's belly as it launched from Florida on Aug. 8 on a construction mission to the space station.
The damage, though small, penetrated through the fragile heat-resistant tile that protects the shuttle during its fiery re-entry through the atmosphere for landing.
NASA has been highly cautious about heat shield damage since shuttle Columbia disintegrated while returning to Earth in 2003, killing the seven astronauts on board.
Columbia's wing shield was broken by loose tank foam at launch, but the damage went undetected and Columbia was destroyed by re-entry heat.
NASA now conducts at least three damage inspections during each shuttle flight and has repair materials on board.
On Wednesday afternoon, astronaut Rick Mastracchio, making the third spacewalk of the mission, spotted a small hole in his spacesuit glove and was forced to cut short his work and go back inside the space station, NASA said.
"There was no issue with leakage, but this is a precautionary measure we do," said lead spacewalk officer Paul Boehm. The suits provide life support and protection for astronauts in the vacuum of space.
Officials were investigating what caused the hole and were looking for a sharp edge somewhere on the space station, spacewalk manager Steve Doering said.
Mastracchio's spacewalking partner, Clay Anderson, completed his remaining work on the station before going back inside.
NASA decided to leave two experiments that the astronauts had planned to retrieve outside the station and reschedule that task for another time.
NASA found a damaged glove after a spacewalk in December and implemented safety checks at least every two hours during future outings to look for damage. The hole in Mastracchio's left glove was found during a routine check.
Last Mod: 16 Ağustos 2007, 11:17