NASA scraps shuttle launch

A FAULTY fuel gauge on Discovery’s external tank forced NASA to call off last night’s launch of the first shuttle flight since the Columbia disaster two-and-a-half years ago.

The US space agency did not immediately set a new launch date.

The decision came with just over two hours to go before launch, as the seven astronauts were almost finished boarding the spacecraft.

Up until then, rain and thunder over the launch site appeared to be the only obstacle to an on-time lift-off.

A launch control commentator said it was unlikely the problem could be solved quickly and another launch attempt today was all but impossible.

NASA has until the end of July to launch Discovery, after which it will have to wait until September a schedule dictated by both the position of the international space station and NASA's desire to hold a daylight lift-off in order to photograph the shuttle during its climb to orbit.

Last night's problem was with one of the four engine cut-off sensors, which are responsible for making sure the spacecraft's main engines shut down at the proper point during the ascent.

A launch could end in tragedy if faulty sensors caused the engines to cut out too early or too late.

NASA said it appeared the sensor was showing a low fuel level, even though the tank was full with 535,000 gallons (2.03 million litres) of super-cold liquid hydrogen and oxygen.

The sensors "for some reason did not behave and so we're going to have to scrub this launch attempt", launch director Mike Leinbach told his team.