Cape Canaveral, Fla. – NASA said Thursday that it is stumped by Discovery’s liftoff foam loss and does not expect another space shuttle to fly until late this year.
Bill Gerstenmaier, the space agency official leading the investigation into the foam loss, said the shuttle’s fuel tank will need modifications, which eliminates any chance of launching in September.
The next available launch time is in November, and anything later than that will hold off a flight till next year because of strict lighting requirements needed to photograph flyaway foam or shuttle damage.
A 1-pound slab of foam insulation broke off Discovery’s external fuel tank after liftoff on July 26 and, unlike the case of the shuttle Columbia, missed hitting the shuttle.
Discovery’s redesigned tank also lost smaller but still sizable and worrisome pieces of foam in four other areas, including the same spot where a large chunk came loose during Columbia’s doomed liftoff in 2003.
“There’s no immediate answer or problem that jumps out at us,” Gerstenmaier said.
Two days after Discovery’s safe landing in California, Gerstenmaier told reporters that of the 4,192 pounds of foam that was on the spacecraft’s fuel tank, only about 1.2 pounds came off at undesirable – even potentially dangerous – times.
That was enough, though, to prompt NASA to ground future shuttle flights just one day after Discovery’s launch.
Gerstenmaier, the program manager for the international space station, stressed that neither he nor other NASA officials are making excuses for the latest foam loss.
“Frankly,” he said, “even the next time we fly the tank, I would expect to see a little bit of foam loss somewhere in the tank. I think it’s an extremely difficult engineering problem to solve.” But the bottom line is “we’re going to have to really understand why this foam came off.”
The space agency’s top worry is the big chunk of foam that came off a hand-sprayed section of the tank where cable trays and pressurization lines need to be insulated. The piece measured up to 36 inches long and 11 inches wide.
Also of concern is the next biggest piece of lost foam, an 8-inch-by-7-inch chunk that engineers suspect may have been caused by a wire to a heater that was installed to prevent dangerous ice buildup during the loading of super-cold fuel. The heaters were added to make up for the removal of wedge-shaped blocks of foam in this area.
