CAPE CANAVERAL, Fla. (AP) — A close-up laser inspection by Endeavour’s astronauts yesterday revealed that a 3½-inch-long gouge penetrates all the way through the thermal shielding on the shuttle’s belly, and had NASA urgently calculating whether risky spacewalk repairs are needed.
A chunk of insulating foam smacked the shuttle at liftoff last week in an unlucky ricochet off the fuel tank and carved out the gouge.
The unevenly shaped gouge — which straddles two side-by-side tiles and possibly the corner of a third — is 3½ inches long and more than 2 inches wide. The inspection showed the damage goes all the way through the 1-inch-thick tiles, exposing the felt material sandwiched between the tiles and the shuttle’s aluminum frame.
Mission managers expect to decide today, or tomorrow at the latest, whether to send out astronauts to patch the gouge. Engineers are trying to determine whether the marred area can withstand the searing heat of atmospheric re-entry at flight’s end. Heating tests will be conducted on similarly damaged samples.
“Thanks to the whole crew for doing a great job of the data taking,” Mission Control told the astronauts once the three-hour inspection ended. “People have a lot of analysis to do now.”
The thermal tiles in the damaged area, near the right main landing gear door, are more than an inch thick. Even if the tiles are penetrated all the way, they are right above the aluminum framework for the right wing, which would offer extra protection against the searing heat of atmospheric re-entry at flight’s end.
This area is subjected to as much as 2,300 degrees during re-entry. A hole, if large and deep enough, could lead to another Columbia-type disaster.
Laser sensors and cameras zoomed in on the damage, white and easily visible against the black tiles, from a variety of views.
Four other damaged areas also were scanned. Engineers think the piece of foam struck the shuttle’s underside, creating the big gouge, then skimmed the bottom and nicked it in at least three other spots.
The foam came off a bracket on the external fuel tank 58 seconds after Wednesday’s launch, fell onto a strut on the tank, then bounced up, into Endeavour’s belly. Ice apparently formed before liftoff near the bracket, which helps hold a long fuel feed line to the tank, and caused the foam to pop off when subjected to the vibrations of launch, said John Shannon, chairman of the mission management team.
Some ice could have been attached to the foam, which would have made the impact even harder. The debris that came off is thought to have been grapefruit-sized.
These brackets have lost foam in previous launches, a concern for NASA, Mr. Shannon said.
Endeavour has been docked at the International Space Station since Friday. It will remain there probably until next Monday for a record 10-day stay.
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