Astronaut Steve Robinson will attempt to remove two small pieces of protruding gap-filler from underneath Discovery during a space walk tomorrow. It will be the first time an astronaut has made an in-flight repair to the underside of the shuttle and is seen as a precaution to reduce the risk of dangerous heat build-up during re-entry. "The tiles are fragile and an EVA crewmember out there is a pretty large mass, so I'll have to be very, very careful but the task is extremely simple and we predict that it won't be too complex," says Robinson.
He'll will first try to remove the pieces of ceramic-fabric gap filler that sit between the shuttle's heat shield tiles using conventional tools, but will have a hacksaw on hand just in case. "The idea is to just pull out this thin gap filler either by hand or with a pair of forceps. We'll use the hacksaw only if neccessary, but I think it's a great solution if we require that and it should be pretty safe," he says.
Flight controllers here in Houston say although it's more than likely the gap filler presents no real danger, they feel more comfortable removing it before the shuttle returns home on Monday.