NASA faces questions about future flights

By Marcia Dunn

updated 6:54 p.m. ET Aug. 21, 2007

CAPE CANAVERAL, Fla. - Even as the wounded space shuttle Endeavour brought its seven astronauts safely home Tuesday, NASA is looking ahead to three more launches at risk for the same kind of damage.

There is a striking parallel with the 2003 Columbia disaster in the space agency’s failure to anticipate the harm from breaking ice or insulating foam — this time from a new area of the shuttle’s fuel tank.

The 3.5-inch-long (9-centimeter-long) gouge in Endeavour’s belly did not put the astronauts at risk. And as soon as the damaged tiles are popped off, engineers will know whether repairs are needed to the underlying aluminum structure. The gash seemed to weather the return flight well, NASA said.

But for the early part of Endeavour’s 13-day mission there was an eerie sense of deja vu.

Back before Columbia flew its last mission four years ago, NASA knew it had a foam problem with its fuel tanks, but never imagined a piece of the airy insulation could severely wound a space shuttle.

The result: Columbia shattered during re-entry to Earth’s atmosphere, just five days before engineers were to propose possible repairs.

This time, NASA knew it had a foam problem with brackets on its fuel tanks, but never imagined a stray piece would ricochet off the tank and smash into the shuttle.

The result: Endeavour was gouged.

Retired Navy Adm. Harold Gehman Jr., who headed the 2003 Columbia investigation, was reluctant to comment this week on the bracket problem. He said he didn’t have enough information.

But he observed: “You have to assume things are going to happen and you have to mitigate the consequences, that’s what our report was all about.”

Endeavour’s gash, although deep, was too small for scorching atmospheric gases to penetrate and cause serious damage, mission managers said during the flight. It was also on the belly, a more benign area than the nose or wings, which are subjected to much higher heat. The plate-size hole that brought down Columbia pierced the left wing.

Officials who checked out Endeavour on the runway said there was no apparent charring to the exposed felt fabric, the last barrier before the aluminum frame.

Temporary solutions weighed
But now NASA finds itself playing catch-up. It’s analyzing a variety of temporary bracket solutions, which may or may not be in place before the next space station construction mission in late October. The temporary solution might have to be used for missions currently scheduled in December and February as well.

Making the brackets with titanium, which would require far less foam insulation than the aluminum version, is the permanent solution ordered after the problem first cropped up last summer.

But that won’t happen until next spring, for a launch currently planned in April 2008. By then, NASA will be nearly two years away from retiring its three remaining space shuttles, after wrapping up a demanding schedule for finishing construction of the international space station.

Engineers are considering a variety of short-term options: shaving some foam from the brackets or possibly applying an oil to the foam to reduce condensation and the buildup of ice.

MORE FROM HUMAN SPACEFLIGHT

Human Spaceflight Section Front

Shuttle, astronauts prep for mid-mission boost What a trip! Space station turns 10 Astronauts finish up spacewalk No. 2 Spacewalker learns from tool mistake Spacewalker loses tools in orbit Astronauts unpack big crate of goodies Shuttle docks with space station Shuttle blasts off for remodeling job India celebrates planting its flag on moon Purified urine to be astronauts' drinking water Human Spaceflight Section Front   Add Human Spaceflight headlines to your news reader: