Sixth time lucky the space shuttle Endeavour launched on Wednesday. But an old problem has returned to haunt NASA: Space foam.
The shuttle Columbia’s tragic ending was caused by a large piece of foam that came off the fuel tank during launch and punched a hole in the shuttle’s wing. On re-entry this hole allowed heat to reach deep into the wing and destroy the spacecraft and its crew of seven.
As Endeavour launched on Wednesday, a camera on the outside of the shuttle showed a number of insulation foam chunks falling off the external fuel tank.
Over at Cnet, William Harwood has a great explanation about what actually happened.
Harwood spoke to shuttle Program Manager John Shannon, who says that the foam seems to have peeled off in strips, instead of bubbling up into little pieces.
“It’s not thick foam at all. The foam is about a half an inch thick, so it kind of came off in little sheets in about seven or eight different areas. We don’t understand why that happened. It looks like the base primer just was not holding onto the foam well,” Shannon says.
The foam came from the intertank area – which separates the hydrogen and oxygen sections of the fuel tank. This isn’t usually the place where foam comes from if it falls off. An Aviation Week story speculates that this was because of the five scrubbed launches meant that the fuel tanks had to be drained and re-filled five extra times, although the piece doesn’t expand upon why that might cause the insulation to strip off in flight.
Some reports are suggesting – perhaps prematurely – that the foam problem could ground the fleet, and damage NASA’s chances of completing its task to build the International Space Station before the shuttle fleet is retired some time in 2010 (Reuters, Discovery, ABC).
The shuttle has docked with the ISS, and its astronauts have been taking a close look at the shuttle with their external camera to check for damage. They are set to return after 16 days.
The foamy lumps aren’t expected to cause any troubles. “There is nothing that we have seen on the orbiter that causes us any concern,” says Shannon.
Image: NASA via cnet