Houston, we have bubbles
2006-07-13 11:34
Cape Canaveral, Florida - Two astronauts lost a bit of time and a spatula during their spacewalk on Wednesday, but otherwise their test of new repair techniques that might some day be necessary to save a damaged space shuttle went well.
The main job of Discovery astronauts Michael Fossum and Briton Piers Sellers, squeezing out putty-like sealant and patting it down, went slowly as bubbles kept appearing in the peanut butter-like material designed to fix cracks in the shuttle's delicate heat shield.
The bubbles were expected, but it meant that the two spacewalkers could only complete seven of their 12 repair tasks in the scheduled six-and-a-half hour spacewalk and were ordered to move on to other work.
"It's behaving very differently now," Sellers said. "It's bubbling. It's growing. It's scary looking."
At times, Fossum worried that they did not have a good repair, but Mission Control was happy with much of the work. The real test will come when the patch jobs are put to test in ground labs after Discovery lands on July 17.
Sellers provided a bit of excitement when the spatula - about the size of a normal kitchen tool - he used to spread the sealant disappeared when he wasn't looking.
"No sign of the spatula; I think it's gone, gone, gone," Sellers said.
Nasa officials said it is not common to lose instruments in a spacewalk, but it's happened before and bigger items have been lost with no ill effects.
But most of the time the astronauts worked smoothly, with wisecracks.
Final spacewalk
At one point as Sellers squeezed out the sealant, he asked Fossum how it looked.
"Good goo?" Sellers asked.
"Good goo!" Fossum responded.
The sealant was squirted onto 12 deliberately damaged reinforced carbon-carbon samples mounted on a pallet in Discovery's open payload bay.
Reinforced carbon-carbon is used to protect the shuttle's wing leading edges and nose from searing heat that can reach 1 260 degrees Celsius during re-entry into Earth's atmosphere.
A crack in Columbia's wing in 2003 allowed fiery gases to penetrate the shuttle, destroying that shuttle over Texas and killing its seven astronauts.
The repair technique was devised by Nasa to make sure such a disaster never happens again.
More than an hour into Wednesday's spacewalk, the astronauts ran into a brief delay when one of Fossum's safety tethers became unlocked.
There was no danger of the astronaut floating away since he is attached to the complex by more than one tether, and he was able to relock it.
Nasa spokesperson Rob Navias said problems like that happen on occasion. During Monday's spacewalk, Seller's safety jet backpack almost came loose while he worked on repairs.
Wednesday's was the third and final spacewalk planned while Discovery is docked at the space station.
On the net:
spaceflight.nasa.gov
- AP