Experts Urge a Reprieve for the Hubble Space Telescope

NY Times ^ | 08/15/03 | DENNIS OVERBYE

[bedolido]

The Hubble Space Telescope, astronomy's vaunted time machine, was granted a conditional reprieve yesterday when an expert panel recommended that NASA consider sending a crew of astronauts at the end of the decade to extend its career, rather than dropping it out of orbit, as has been planned.

But the committee said its recommendation should be carried out only if the science to be performed in those additional years was able to beat competing proposals for new NASA science projects.

For the last 13 years, floating above the Earth's murky atmosphere, the telescope has beamed down crisp images of galaxies still forming at the dawn of cosmic time, peering into the hearts of galaxies and quasars in search of black holes, and investigating the mysterious "dark energy" that seems to be wrenching the cosmos apart.

"By any standards the H.S.T. has been a spectacular success — one of the most remarkable facilities in the entire history of science," said the committee, whose chairman is Dr. John Bahcall of the Institute for Advanced Study in Princeton, in a report posted yesterday on the Web site of the National Aeronautics and Space Administration.

The committee members and other astronomers pointed out, however, that since the breakup of the Columbia shuttle, the telescope's future has been threatened because it is hostage to the ability of a space shuttle to pay periodic visits for maintenance and to replace old instruments with new ones.

Those repair missions would take the shuttle too far from the orbit of the International Space Station in case of trouble. As a result, the space agency should be prepared for a range of possibilities, the report said, from no more shuttle missions to two.

More is likely to be heard on that score in a couple weeks when the report of the Columbia Accident Investigation Board is released. But ultimately, Dr. Bahcall said, Congress, the White House and the NASA administrator will decide whether the shuttle may visit the telescope.

Dr. Anne Kinney, who is in charge of astronomy and physics in the space agency's office of space science, said that the Bahcall committee's report was "a good report."

"It reminds us that we need to be flexible," Dr. Kinney said. But she added that there was no budget for the extra mission and no precedent for the kind of competition that Dr. Bahcall and his colleagues had proposed.

"It's going to be a challenge," she said.

Astronomers were generally pleased with the report. Dr. Wendy Freedman, director of the Carnegie Observatories in Pasadena, Calif., called it "balanced and thoughtful."

Dr. George Rieke, an infrared astronomer at the University of Arizona, said the idea of a competition was "a sensible way to deal with limited resources."

Dr. Steven V. W. Beckwith, director of the Space Telescope Science Institute, praised the report, saying, "I couldn't be happier."

He added:"Everyone here is tremendously grateful to NASA for its support of the Hubble. We're delighted to have the chance to compete to continue this extraordinary story."

The story of the $1 billion Hubble, launched in 1990, is one of the great comeback stories in modern science. It was designed to take advantage of an orbital vantage point above the Earth's atmosphere, which smears images and blocks some wavelengths of light from reaching ground-based telescopes.

Once it was in orbit, however, astronomers were devastated to discover that the telescope had a flawed mirror.

The flaw was corrected in 1993 by sky-walking astronauts who, in effect, fitted the telescope's instruments with corrective lenses, enabling Hubble to attain the glory for which it was designed.

NASA has long planned to end Hubble's spectacular run and bring it down to make way in the budget for the James Webb Space Telescope, now scheduled to be launched in 2011. But some astronomers have urged that Hubble's life be extended, arguing that the telescope has grown even more productive in its years in orbit, and that the Webb could be delayed.

Moreover, the Webb is being designed for the infrared wavelengths that very distant galaxies would be emitting as they sped away in the expanding universe, not the visible wavelengths that Hubble sees so exquisitely.

The panel that NASA asked to review the issue also includes Dr. Barry Barish of the California Institute of Technology, Dr. Jacqueline Hewitt of the Massachusetts Institute of Technology, Dr. Christopher McKee and Dr. Charles Townes, both of the University of California, and Dr. Martin Rees of Cambridge University in England.

One of the main elements in their thinking, Dr. Bahcall said, was the realization that NASA might have to mount a mission to the telescope anyway at the end of the decade to attach a rocket to bring it out of orbit safely. The telescope is too big to be left to tumble out of orbit by itself.

The space agency had originally hoped to grab it with the shuttle, bring it back to Earth and put it in the Smithsonian Air and Space Museum, but the Columbia disaster scuttled that option.

NASA is looking into developing a robotic spacecraft that could attach itself to the telescope, but many astronomers argued that the job could be done more reliably by astronauts. And if the astronauts are there anyway, they said, the telescope could be spiffed up for another few years of science.

Another element was the inspirational qualities that Hubble has both for astronomers and for the public, Dr. Bahcall said.

[bedolido]

[Nonstatist]

The next repair mission is next year, with the shuttle. Theyre going to have to set up another one in maybe '07 (replace gyros as well as add new science instruments). That gets you until '10 , maybe. Then after that they could go back up with the shuttle (or some other way?) and add boosters so that they can reset orbit to geo-sync (22000 miles) and let it ride out the last couple years, without maintainance. That way you dont have to worry about retrieval or burning up in reentry, landing who knows where... Sounds like a plan !?

[theDentist]

Something working as well as Hubble, and costing as much, shouldn't be jettisoned due to age while it is still providing us such great insights to the Universe.

[Cincinatus]

NASA is looking into developing a robotic spacecraft that could attach itself to the telescope, but many astronomers argued that the job could be done more reliably by astronauts.

What??!?? Paragons of modern science actually advocating something significant in space can be done by mere humans!?!? Be still my fluttering heart! Oh my...I'm getting the vapors.....

[bedolido]

Sounds like a plan !?

Thanks for the insight...

[js1138]

another one for the ping list

[balrog666]

Something working as well as Hubble, and costing as much, shouldn't be jettisoned due to age while it is still providing us such great insights to the Universe.

Exactly! Why should it join Sky Lab?

[RonF]

It's there. It works. It would be nuts not to keep using it. Ground-based telescopes that are 50 and 100 years old are still being productively used for research. Not keeping Hubble going would be foolish, especialy at least until it's replacement was up and running. There's still plenty of work that Hubble can do; not everyone who wants time on the new system will get it.

[Joe Hadenuf]

Bump.....

[RonF]

Being in geosynchronous orbit doesn't make it magcially stable. Geosynchronous orbits degrade, too; those communications and other satelites up there need rocket engines and periodic manuevers to maintain station. In fact, that's how one was lost a couple of years ago; during a station-keeping manuever, someone made a mistake and put the sattelite into a spin that prevented it's command antenna from maintaining an Earth fix, so it couldn't receive the command to stop. Apparently no one put a "If you don't hear from the ground for a day, do some star fixes and re-orient yourself to Earth" command in the software.

The other thing is that there are limited numbers of geosynchronous slots available (they maintain spacing among these guys), so you don't want to waste one parking something there permanently.

[RonF]

I visited the Yerkes Observatory 2 years ago, and checked out the 40" (the largest refractor in the world). It was built in 1897 and is still used for research. One thing they use it for is to take star pictures. These are compared to pictures of the same stars taken up to over 100 years ago so as to measure proper motions. At the time the initial pictures were taken this was the world's largest telescope, so you can make precise measurements of proper motions possible with no other telescope in the world.

I was at a Scout meeting at George Williams College next door, but skipped out to take a tour of the facility (9:30, 10:30, and 11:30 Saturday mornings), on the justification that I'm an Astronomy MB counselor, plus I just wanted to.

[Nonstatist]

The prelim plan is to attach a pair of ion engines to HST and boost slowly to the rqd orbit. Doing this was previously the second choice to bringing it down and putting it in the Smithsonian, but now this option is now off the table, permanently. And a controlled burn reentry will be pretty much impossible given its size and the mass of slow melting metals like Titanium, etc.

Besides, geo synch orbit will allow even better pictures to come across (no grav pull distortions), and is a backup in a way to the JWST, with its risky deployable mirror, etc. And who knows when that will launch, given budgetary and other constraints?

[bedolido]

They're considering a replacement for the Hubble (named after another great astronomer). This new Hubble replacement will be slightly larger with the mirror going up in several pieces. This new mirror will allow more light in thus bring objects from deep space even closer.

[bedolido]

getting into the correct orbit is a main concern. Too far out and it takes more power to operate. As it is now, the Hubble has only two working gyros out of four. If they lose one more they won't be able to control it and will have to shut it down. The window between getting the shuttles back online and the degrading hubble orbit will be very close. That's why they're considering a robotic attempt to capture it and move it out farther.

[RonF]

Putting the Hubble in geosynch orbit would make it non-servicable. No replacement of cameras, no repairs, no new instruments, etc. Not a good idea, in my opinion.

[RonF]

Yeah, that's the new James Webb telescope. But there are the usual concerns about when it will actually launch and see first light, and even when it's up there, why not have still use the Hubble as well?

[Nonstatist]

Non serviceable, but still it would be useful for some time (2,3 years). Invaluable information to be gotten. And whats the alternative, except reentry burn?

[Nonstatist]

There another servicing mission next year, all ready to go. Theyre just waiting on shuttle use ok. If the next gyro goes, no more science until the shuttle gets there, and that could be moved up, providing this report goes through and theres no flack from the politicos..

Its feasable to boost HST with its own power source (attached somehow); Im just not sure about whether it gets funded.

[RonF]

The alternative is to keep it where it is and spend the money to service it. There is a considerable capital investment in this thing that can continue to be taken advantage of. Tossing it away, or greatly limiting the rest of its useful life just because another 'scope is to be launched makes no sense to me.

[PatrickHenry]

PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]