The National Aeronautics and Space Administration announced mid-January it would stop, for safety reasons, sending astronauts to service the telescope, effectively condemning the Hubble to an early demise.

NASA chief Sean O'Keefe said he has asked the National Academy of Sciences to examine options to save the telescope before it loses its fuel reserves in

The options include "autonomous robotic capabilities to provide a power generation capability that is capable of extending the operational life of the Hubble," O'Keefe told reporters at NASA's Washington office.

The academy would also consider the possibility of sending astronauts, but "we are not likely to be able to do that," he said.

NASA officials are not sure they will be able to meet new security measures that were put in place after last year's Columbia shuttle accident.

However, O'Keefe said, there are "very promising concepts on extension of power generation capabilities robotically."

"These options appear more likely than the low probability of a timely servicing mission in compliance with the board recommendations," he added.

Scientists have lobbied Congress for the continuation of Hubble's maintenance since NASA announced it would stop servicing the telescope.

The new James Webb telescope will be launched in 2011.

On Wednesday, Senator Barbara Mikulski, who heads up a campaign to prevent abandonment of the Hubble, told O'Keefe she was "surprised and shocked" by the decision to scrub the shuttle mission to the telescope.

She asked admiral Harold Gehman, who chaired the investigation, for his advice on NASA's decision. She said his response was that a shuttle mission to the Hubble would be "slightly more risky" than missions to the International Space Station.

SPACE.WIRE