NASA to replace space shuttles' key parts after problems found

Published on Wednesday 24 March 2004 00:00

NASA is planning to replace key parts on its space shuttle fleet after it discovered a potentially disastrous mistake made more than 20 years ago which could have caused the craft to explode on landing.

Gears on the space shuttle Discovery were installed backwards on the speed brakes in the craft’s tail section and could have failed under the stress of an emergency landing, said William Parsons, the shuttle programme manager.

"The bottom line was, it was not good," said Mr Parsons, who said the Discovery had flown safely 30 times since 1984 without the gears causing a problem.

The most likely conditions for a disaster would have arisen if the shuttle had needed to make an emergency landing at the Kennedy Space Centre in Florida after an aborted launch, when the aerodynamic stress on the gears would have been greatest.

The reversed gears were found in an actuator that works the speed brakes - flaps that flare out from the tail section to create aerodynamic drag and slow the shuttle. Small cracks and some corrosion were also found.

After the original parts were replaced, NASA tested the replacement parts, built 17 years ago, and found one also had the gears reversed.

Discovery is NASA’s oldest remaining shuttle after the loss of the Challenger in 1986 and the Columbia in 2003. It has been chosen as the shuttle that would return NASA to flight status.

That mission is scheduled for March 2005 and Mr Parsons said the added work would not necessarily require a delay.

Parts are being stripped from the newer shuttle, Endeavour, to be installed on Discovery, but eventually NASA said it will have new parts on all three remaining shuttles. Atlantis is the third.