Extending Hubble's mission considered

HOUSTON, Oct. 14 (UPI) -- Although the Hubble Space Telescope is scheduled to be shut down in 2010, extending it beyond that deadline would enable scientists to use it in conjunction with the NASA's new telescope -- the Next Generation Space Telescope or NGST -- a leading astronomer said Monday.

"I think that astronomers would like to see (an overlap)," said Steven Beckwith, director of NASA's Space Telescope Science Institute in Baltimore. "Hubble works at visible wavelengths and ultraviolet wavelengths in particular. The Next Generation Telescope should go down into the visible (range of the spectrum) but not with the same kind of resolution."

Scientists especially would not like to see a gap between closing down Hubble and starting up the NGST, which uses different wavelengths to study the depths of space, he said.

Beckwith spoke to attendees at the World Space Congress in Houston about discoveries made with the Hubble telescope and the program's future. The Hubble, which was launched in 1990 and orbits about 375 miles (600 kilometers) above Earth, carries incredibly sensitive instruments. For example, one device can detect minute changes in the light from a distant star, such as when a planet passes in front of it and blocks the view, thereby enabling researchers to determine the star's size and partially deduce its composition.

The Hubble's data has supported the theory of dark matter, the notion there are substantial amounts of matter in the universe that, so far, have eluded detection. Most striking, data obtained by measuring changes in light from supernovas has led to the discovery the universe actually is expanding at an accelerating rate -- not slowing down as one might expect.

Over the past 12 years, Hubble has been repaired and upgraded regularly with new and better instruments and is scheduled to be upgraded for the last time in June 2004. Prior adjustments to the $10 billion project include new cameras and instruments using ultraviolet, visible and infrared wavelengths. Pictures from Hubble of spectacular space clouds and meadows of galaxies have captured imaginations worldwide.

The Hubble has "given us new theories about (the nature of) matter" said George Uspensky, head of department at the Central Research Institute of Machine Building of the Russian Aviation and Space Agency. Uspensky told United Press International that Hubble data eventually could reveal new information about the interactions between gravity, energy and matter.

In 2010, the same year Hubble is set to be deorbited, the NGST -- now officially named the James Webb Space Telescope, after the former NASA administrator -- is to be launched.

Extending Hubble's operational lifetime beyond 2010 would require $30 to $40 million per year, Beckwith told UPI, and money is the key issue involved in deciding whether to extend Hubble or not. Yet Ed Weiler, NASA's space sciences chief, said earlier this year funding NGST is dependent in part on shifting money from Hubble.

Additional Hubble service missions mean additional and costly space shuttle flights, and any decision to perform another upgrade and keep the telescope online would have to be made soon because planning for such a flight takes about five years. The gyroscopes and the reaction wheels that keep the telescope pointed properly need to be replaced periodically and the solar arrays, which power the systems, decay over time.

"Hubble is based on 1970s and 1980s technology," said Weiler. "You reach a point where there is only so much more you can do. Besides, we have an agreement with the scientific community to fund NGST, which we can do by eventually eliminating funding for Hubble."

There is no question, though, that Hubble still provides solid research opportunities. Beckwith noted the Hubble team turns down 85 percent of research requests made by scientists seeking to use the telescope. Fully half of the proposals made are excellent, he said in response to questions, meaning many worthy research projects do not get done.

The Webb Telescope will be launched beyond the moon, placing it out of range for shuttle service flights or upgrades.

(Editors: UPI photos # WAX2002101401, WAX2002101402 and WAX2002101403 available)