Shuttle close call stymies review panel

SPACE CENTER, Houston -- The leader of an expert panel that evaluated NASA's return to flight effort expressed shock Friday at the space shuttle's close call with a chunk of fuel-tank debris.

Former astronaut Richard Covey said he expected to see only a small amount of foam insulation shedding from the fuel tank during Discovery's launch because of all the work NASA engineers did to redesign the tank since the Columbia disaster.

"I am surprised," the veteran shuttle commander said in a telephone news conference with reporters at Johnson Space Center Mission Control.

Onboard video cameras captured at least four potentially deadly pieces of insulation flying away from Discovery as it rocketed into orbit Tuesday. Only one of the four came close to the shuttle's heat shield, and whether that one hit the vehicle is not clear. NASA has not reported any significant damage.

The insulation broke loose from a region of the mammoth fuel tank that NASA engineers argued did not need to be redesigned. "Clearly the rationale that we accepted was wrong," Covey said.

He co-chaired the federally chartered Return to Flight Task Group which assessed NASA's compliance with a host of safety requirements spelled out by investigators of the February 2003 accident that killed seven astronauts.

The Columbia Accident Investigation Board found that the orbiter disintegrated during atmospheric re-entry because - unbeknownst to mission managers -- a piece of fuel tank insulation had poked a hole in its heat shield.

Investigators ordered NASA to begin an aggressive program to eliminate all sources of potentially deadly liftoff debris. The agency had not met the requirement by the time the task force finished its work in June, but the group said NASA had worked hard to satisfy the investigators' intent - which was to make shuttles safer.

As shocking as the foam loss was, Covey said he wouldn't be afraid to fly a shuttle again, if he was offered a chance.

Meanwhile, NASA engineers continue to analyze photography and radar images from Discovery's launch as well as visual and laser data the astronauts have been gathering in space. Mission managers said Friday they are growing more confident up in space, and mission managers say they're growing more confident that Discovery is in good shape to come home to Earth at the end of its mission without needing repairs.

The NASA administrator told reporters by telephone from Washington this morning that "work done on the external tank has reduced scarring on the orbiter by a factor of six" compared with liftoff damage seen on the 112 orbital flights to date. However, Michael Griffin said, the debris problem "makes it even more clear that we need to retire the shuttle in an orderly way" by 2010, if not before.

Aboard the International Space Station where the shuttle is docked, the combined crews - nine in all -- Friday unloaded supplies from an Italian-built cargo module that Discovery delivered. Shuttle astronauts Stephen Robinson of NASA and Soichi Noguchi of the Japanese Space Agency made final preparations for a Saturday spacewalk, the first in a planned series of three.