NASA's final shuttle flight slips to November

The space shuttle Endeavour returns to the Kennedy Space Center in Cape Canaveral, Florida, February 21, 2010.

CAPE CANAVERAL, Florida (Reuters) - NASA's last space shuttle mission will be delayed until November so scientists can adapt a $2 billion particle detector for an extended life aboard the International Space Station, officials said Monday.

Three more shuttle flights remain and the space agency had planned to close out the program by September 30 with a final mission by shuttle Discovery to resupply the orbital outpost.

That mission now moves ahead of shuttle Endeavour's launch with the Alpha Magnetic Spectometer, a 16-nation project overseen by Nobel laureate Samuel Ting, a physicist at the Massachusetts Institute of Technology.

"It became clear that (Endeavour) could not fly in July like was on the manifest," said NASA spokesman Kyle Herring.

AMS, which is designed to look for antimatter particles and other exotic forms of matter in space, had been set to fly in July. But with the Obama administration's proposal to extend the space station program until at least 2020, scientists decided to switch the detector's cryogenically cooled superconducting magnet, estimated to last three years, to a permanent magnet that would last 10 to 18 years.

"We began thinking about this at the end of last year and the beginning of January when people were talking about the space station going to 2020 and beyond," Ting said in an interview.

"I began to realize that we'd have a museum piece."

Dumping AMS' liquid helium-cooled magnet cuts the device's power to bend the path of charged cosmic particles as they pass through five different types of detectors. But Ting says adding more precision detectors and the extra years in orbit more than compensates for that.

The replacement magnet, which flew in a prototype AMS during a 1998 shuttle mission, was taken out of clean room storage in Germany and tested. No degradation was found and it is scheduled to arrive at CERN -- the European Organization for Nuclear Research -- in Geneva where the AMS is being assembled this week.

Delaying the last shuttle flight will give the 6,000 to 8,000 workers at the Kennedy Space Center preparing for layoffs a short reprieve.

Obama's budget request for NASA for the year beginning October 1, which still must be approved by Congress, includes $600 million to keep the program going until the end of the year if necessary to accommodate technical or weather-related delays.

The schedule change is not expected to affect the final planned flight of shuttle Atlantis, targeted for liftoff on May 14 to deliver a Russian docking port to the station.

(Editing by Tom Brown)