NASA urged to send astronauts to fix Hubble telescope.

Byline: Mark Carreau

Dec. 9--The nation's most prominent science advisers Wednesday urged NASA to send shuttle astronauts instead of robots on a repair mission to the aging Hubble telescope because humans have a substantially greater chance of fixing it.

The congressionally chartered National Academy of Sciences became the second independent panel in as many days to raise significant doubts about the robotic repair strategy favored by NASA Administrator Sean O'Keefe.

Earlier this year, O'Keefe canceled plans to send shuttle astronauts to Hubble in 2006 because he deemed the mission too risky in wake of the Columbia accident. Instead, O'Keefe asked NASA to prepare for a robotic mission by 2008 to save the $5.6 billion telescope.

But the national academy Wednesday said a shuttle repair mission had a 70 percent chance of success. It said a robotic mission had a 20 percent chance of working. The panel of 26 experts also concluded that Hubble's contributions toward understanding the birth and evolution of the universe were worth what it considers a small risk to astronauts' lives.

On Tuesday, a California-based aerospace think tank gave robots a 50-50 chance of fixing Hubble.

"Hubble is an extraordinary accomplishment that has had major scientific and public impact," said Louis Lanzerotte, the New Jersey physicist who chaired the national academy panel. "It has the capacity to do so for years to come."