Nasa postpones space shuttle launch


Nasa is postponing launch of space shuttle Atlantison a mission to deliver Europe's science laboratory to the International Space Station until January at the earliest, Nasa officials said today.

Two attempts to launch this shuttle mission were canceled since Thursday because of problems with a fuel sensor that is part of an emergency engine cutoff system.

Two of the four sensors in the ship's hydrogen tank failed during Nasa's first launch attempt on Thursday. One of them failed again when the tank was being filled for a second launch try today.

"The Mission Management Team is still meeting, but we are off until no earlier than January 2nf," said Nasa spokesman Allard Beutel.

The sensors, which operate like dipsticks to determine fuel levels, are part of a backup system to cut off the shuttle's three hydrogen-burning main engines if the tank runs dry due to a leak or other problem.

Running the engines without propellant could cause their pumps to break and possibly trigger a catastrophic explosion.

Disasters in 2003 and 1986, which killed the crews aboard the shuttles Columbiaand Challenger, have made Nasa especially cautious about launch safety.

Nasa has 10 shuttle flights remaining to complete construction of the $100 billion space station. It also wants to make two resupply flights and a servicing call to the Hubble Space Telescope before the shuttle fleet is retired in 2010.