NASA to decide whether to repair space shuttle

NASA says it will decide tomorrow whether it will need to repair a deep gouge in the space shuttle Endeavour's protective tiles. Experts have conducted tests to determine whether the damage to the orbiter's belly poses a risk to the astronauts during re-entry to the atmosphere. The gash was caused by a piece of foam striking the shuttle at lift off.

Shuttle mission managers are trying to decide whether Endeavour's astronauts should carry out an additional, risky space walk to patch up the gouge in the shuttle's belly, or whether the damage is benign enough for Endeavour to fly safely home. It is a tricky decision - similar damage to the shuttle's thermal protective tiles caused the break up of the space shuttle Columbia in 2003 during re-entry to the atmosphere, with the loss of all Astronauts on board.

But NASA has never attempted this type of emergency repair on an orbiting shuttle, and two of the three remedies - all developed following the Columbia disaster are untested in space, making it very risky. John Shannon from NASA's mission management team says he will need to balance the risks before deciding whether to ask the astronauts to carry out a repair space walk - also known as an extra vehicular activity or EVA.

Foam falling
The gouge in the shuttle is relatively small but part of it penetrates through the protective thermal tiles, leaving just a thin layer of felt material over the space shuttle's frame. It is believed it was caused by foam falling off a hinge on the shuttle's external fuel tank during launch. Despite extensive redesigning of the tank, foam has repeatedly fallen off during launch. NASA's John Shannon says, if possible, he would rather not carry out a repair, and devote more time to construction of the international space station.

Experts are pouring over data from the shuttle in an effort to determine whether to order a space walk. John Shannon says he's not yet ready to make the call. Depending on how NASA addresses the latest foam problem, space shuttle flights could possibly come to a temporary halt, stalling construction at the international space station once more.