NASA Weighs Robot Mission to Telescope
By KENNETH CHANG, June 2, 2004, New York Times
DENVER, June 1 - Four and a half months after he seemed to doom the Hubble Space Telescope by ending maintenance missions by the space shuttle, NASA's administrator, Sean O'Keefe, brought brighter news to astronomers on Tuesday by announcing that NASA was seeking proposals for a robotic mission to extend Hubble's life.
The decision is a compromise between Hubble supporters who would like Mr. O'Keefe to reinstate the shuttle mission and the initial prospect that an otherwise still useful telescope would be left to die for want of a few parts. Left alone, the telescope will be able to operate for about three more years before the failure of gyroscopes would render it unable to point at the stars.
In a speech to scientists at a meeting here of the American Astronomical Society, Mr. O'Keefe stood firm in his decision to cancel the shuttle mission, but said: "Fortunately, there may be other options for extending the Hubble's useful work. Good options that are looking more promising as we've examined them more closely. Our confidence is growing that robots can do the job."
In January, two days after President Bush laid out a vision for NASA emphasizing human exploration of the Moon and Mars, Mr. O'Keefe canceled any future shuttle missions to Hubble, citing safety concerns. The next trip, scheduled for next year, would have replaced batteries and gyroscopes and installed two new instruments.
That generated an outcry from astronomers, politicians and space enthusiasts, and NASA began examining other ways to maintain Hubble, leading to Tuesday's formal call for proposals.
Dr. Steven Beckwith, director of the Space Telescope Science Institute, which runs the telescope's science program, said a robotic mission appeared to be technically feasible. "As a scientist, I support the development of that technology very, very strongly," he said, but added that he would like planning for a shuttle mission to continue at the same time. But if a robotic mission could not install the new instruments, which is the hardest task, "I would be disappointed," he said.
Shuttle astronauts have visited Hubble four times, swapping out broken components and adding improved instruments that have enabled clearer and deeper pictures of the universe. The first mission in 1993 transformed Hubble from a technological turkey - with a flaw in the mirror that led to initial fuzziness - to a hugely successful instrument.
Mr. O'Keefe is now calling for proposals in three areas. The first is to develop a robot to dispose of Hubble; NASA had previously agreed that instead of using the shuttle to bring it back to Earth, it would develop a robotic mission to dock with the telescope and guide it to a fiery but safe re-entry into the atmosphere.
Now, with the prospect that the robot mission could also be used to perform the maintenance, NASA is calling for proposals to install new batteries and gyroscopes and to install the two improved instruments, already built at a cost of $200 million.
"What we are looking for is not autonomous robotics, but tele-robotics," Mr. O'Keefe said. "If this mission goes forward, people will still be servicing Hubble."
Proposals are due July 16. Mr. O'Keefe said he expected that NASA would take six to eight weeks to evaluate the proposals before deciding the next step in the process.
He portrayed the robotic option as a win-win solution for all. Astronomers would gain years of use of Hubble, and NASA would develop technology of use in the future. "Such a mission will open the door to more ambitious robotic activities to assemble and service massive telescopes in space, as outlined in the new vision for space exploration," Mr. O'Keefe said. "Indeed, it is a precursor to our efforts to construct advanced telescope searches for Earthlike planets and habitable environments around other stars."
Dr. Rodger Thompson, an astronomy professor at the University of Arizona and the principal investigator for Hubble's infrared camera said, "I was encouraged by the administrator's commitment to pursue a robotic option," but he added that he was disappointed that the same effort would not be applied to pursuing a possible shuttle mission.
"We would definitely like to have both options available to us," Dr. Thompson said. "I would say the science return for one mission to the Hubble Space Telescope will far exceed the science return that will result from 24 missions to the International Space Station."
Source:
http://www.nytimes.com/2004/06/02/science/02nasa.html
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