Cape Canaveral, Fla. – NASA conducted a swift series of tests on the ground Monday to determine whether spacewalking astronauts need to fix a deep gouge in Endeavour’s belly for re-entry, and assembled a special team to weigh the three repair options.
The gouge is relatively small – 3 1/2 inches by 2 inches – but part of it penetrates through the protective thermal tiles, leaving just a thin layer of coated felt over the space shuttle’s aluminum frame to keep out the more than 2,000-degree heat of re-entry. The exposed area is 1 inch long and less than a quarter-inch wide.
Mission managers expect to decide by Wednesday whether astronauts should go out and patch the gouge. The damage is considered benign enough for Endeavour to fly safely home; it’s more a matter of avoiding extensive post-flight repairs to any possible structural damage, said John Shannon, chairman of the mission management team.
“This is not a catastrophic loss of orbiter case at all. This is a case where you want to do the prudent thing for the vehicle,” Shannon said Monday evening.
NASA has never attempted this type of repair on an orbiting shuttle, and two of the three remedies – all developed following Columbia’s catastrophic re-entry – are untested in space.
Engineers don’t know if it was foam insulation that came off Endeavour’s external fuel tank and struck the shuttle at liftoff, as was the case for Columbia four years ago, or whether the debris was ice or a combination of materials, Shannon said.
Depending on how NASA addresses the latest problem, space-shuttle flights could possibly come to a temporary halt.
To patch the gouge, spacewalking astronauts would have to perch on the end of the shuttle’s 100-foot robotic arm and extension boom, be maneuvered under the spacecraft, and apply black paint, screw on a protective plate or squirt in goo.
The black coating, intended to dissipate heat, was tested on a previous shuttle flight. The two other repair methods have been tested in vacuum chambers on Earth, but never in space.
