Analysis for UPI
Washington (UPI) Mar 10, 2004
Several factors are combining to suggest the fate of the Hubble Space Telescope -- which NASA administrator Sean O'Keefe has said will never again be visited by a space shuttle repair mission -- might not be a foregone conclusion.
On Jan. 16 O'Keefe announced he had canceled a shuttle mission scheduled for 2005 to repair and upgrade the Hubble. The decision effectively condemned the telescope to oblivion sometime in the next few years, whenever its batteries or one or more of its still-operating gyroscopes fail, leaving the Hubble incapable of maintaining a fix on a target object.
The shuttle mission would have represented the fourth visit to the Hubble since its launch in 1990. It was supposed to be conducted after NASA resumed flights of the shuttle fleet. The remaining three orbiters have been grounded since Feb. 1, 2003, when shuTtle Columbia disintegrated during its attempted re-entry into the atmosphere.
Even if NASA manages to overcome shuttle safety concerns and return the spacecraft to flight, however, O'Keefe has decided to confine all remaining shuttle missions to rendezvous with the International Space Station.
Such missions would offer shuttle crews the option, in an emergency, of remaining aboard the station until a rescue craft could be dispatched, while a shuttle flight to the Hubble would not offer the safe harbor option.
The Hubble repair mission was supposed to supply the telescope with gyroscopes to replace two that currently are malfunctioning, plus any others in need of replacement, and new batteries.
Hubble carries a total of six gyroscopes and can perform its scientific missions with as few as three in operation. NASA estimates the chances of three gyroscopes remaining functional by July 2006 at only 30 percent. Any further failure would severeLy limit Hubble's ability to carry out meaningful science.
The mission also was supposed to deliver a powerful new wide field camera and spectrometer. According to NASA's memo, officials now will examine options for using the instruments on satellites.
Hubble's loss would leave the future of space-based, visible light astronomy unfulfilled for many years. The James Webb Space Telescope, scheduled for launch in 2010, operates in the near-infrared spectrum.
Not that the Webb, being built by TRW of Redondo Beach, Calif., will not carry spectacular potential. Its mirror will feature six times the light-gathering capability of Hubble and will be able to see objects 400 times fainter than those observed by the best ground-based telescopes.
The new telescope's primary mirror will contain 36 semi-rigid hexagonal segments that will be 20 feet in diameter, compared with the Hubble's 8 foot mirror.
The Webb -- named for the former NASA administrator who died in 1992 -- represents a much riskier venture than the Hubble, which orbits 375 miles up -- designed to keep it within range of space shuttle repair and upgrade missions. The Webb will operate some 1.5 million miles away from Earth, at a place called the LaGrange point, where the gravity of the sun and the Earth cancel each other out.
The vast distance is necessary to keep the telescope and its instruments at very low temperatures without complex refrigeration equipment because its infrared observations need to be shielded from the light and heat of both the Earth and the sun.
The Webb's advanced instrument package will enable it to study such phenomena as star and galaxy formation, extrasolar planets, supernovae, black holes and the mysterious components of the universe known as dark matter and dark energy.
Beyond the Hubble, however, the next attempt at Visible light, space-based astronomy remains well into the future -- at least not for another 10 years. That is one reason why, although O'Keefe intended his Hubble decision to be final, scientists and politicians are joining in an effort to force a reconsideration.
Sen. Barbara Mikulski, D-Md., whose state harbors the Goddard Space Flight Center in Greenbelt, where Hubble's mission is controlled, has gotten O'Keefe to agree to permit an independent review of his decision to terminate further shuttle missions to the Hubble.
"My view is when someone is told they need major surgery, any prudent person would get a second opinion," Mikulski said in a statement. "That's what I told administrator O'Keefe and that's what he has agreed to do. Hubble has made so many extraordinary contributions to science, exploration and discovery. We cannot prematurely terminate the last servicing mission without a rigorous review."
O'Keefe toldMikulski -- who is the ranking member on the appropriations committee that oversees NASA's budget -- that Adm. Harold Gehman, chairman of the Columbia Accident Investigation Board, will lead the review. It is quite possible Gehman will conclude that a shuttle mission to the Hubble poses no more intrinsic risk than a mission to the space station -- despite the potential of the station to function as a lifeboat for the shuttle crew.
Rep. Mark Udall, D-Colo., introduced a bill in the House last week urging NASA to establish an independent panel of experts to review the Hubble decision.
"This resolution will be welcomed by scientists and interested citizens in this country and around the world, who understand that Hubble is a national treasure that we should not abandon," Udall said in a statement." The potential gains from extending Hubble's life are real and achievable -- and I believe we should not arbitrarily cancel the servicing mission Without exploring all options for safely carrying it out."
Both moves represent encouraging signs to the astronomy community, which has worried O'Keefe made his decision to cancel the Hubble servicing mission, at least in part, to save money to help fund President Bush's new space exploration initiative.
Bush's plan, announced Jan. 14, calls for returning humans to the moon and mounting expeditions to Mars and elsewhere in the solar system in the coming decades.
"Things are going our way right now," said Stephen Beckwith, director of the Space Telescope Science Institute in Baltimore, which supervises Hubble's images and data. "A lot of people at this institution still think a miracle could happen."
Beckwith added he is trying to "be realistic" about Hubble's chances, however. He said his team is assuming Hubble's operational life may have only a few years left, so mission scientists are trying to develop ways to extendThe telescope's battery life and to function using only two gyroscopes instead of three. If successful, they might be able to extend Hubble's operations several more years.
"I think it's just too early to know," Beckwith cautioned. "Within the project, all of us who know this telescope are scared to death that it will wind up in a tumbling state that would be exceedingly challenging to retrieve under any circumstances."
One formidable factor in Hubble's favor is its own continuing ability to produce stunning and unprecedented images of the heavens.
Take the latest offering is a composite image produced by the telescope's ultra-deep field camera and its own infrared instrument. It reveals a patch of sky that represents the oldest and most distant collection of galaxies ever seen from Earth, portraying thousands of galaxies that emerged almost at the beginning of the universe.
The image is a time capsulE, stretching back more than 13 billion years and showing galaxies as they existed only about 700 million years after the Big Bang.
The image also is ironic as it was made possible only because shuttle astronauts rendezvoused with the Hubble in 2002, repairing its infrared camera and installing the ultra-deep field.
The next upgrade to Hubble's infrared camera, which was scheduled to be installed in the next shuttle mission, would be 10 times more powerful than the current one.
Phil Berardelli is UPI's Science & Technology Editor
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Another Modest Proposal for the Future of the Hubble Telescope
Houston - Sep 01, 2003
A recent article in SpaceDaily.com explored the possibilities for servicing the Hubble Space Telescope (HST) by Shuttle, Orbital Space Plane (OSP) or Soyuz. There are problems with all three of those contingencies, not the least of which is that the OSP hasn't even been designed yet.
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