Riding to Hubble's rescue
Posted: Friday, June 09, 2006 2:16 AM by Alan Boyle
NASA / ESA / STScI / AURA |
This Hubble view shows the disk galaxy
NGC 5866 tilted nearly edge-on to our
line of sight. A crisp dust lane divides
the galaxy into two halves. Viewed face
on, NGC 5866 would look like a smooth,
flat disk with little spiral structure.
|
The scientists behind the Hubble Space Telescope delivered yet another stunning celestial image on Thursday, showing a galaxy on edge with a wispy glowing halo. "Hubble-huggers" have been on edge as well, hoping that NASA will send a space shuttle crew to extend the life of space-based astronomy's crown jewel. Although the space agency hasn't yet set a date for that final servicing mission, the shuttle program's manager says preparations are already being made for a rescue.
Shuttle crews have visited the Hubble for servicing four times since the telescope's launch in 1990, and the fifth mission would rank right up there with the first one, which effectively gave Hubble its sharp-eyed sight. New gyros and batteries would replace the ones that are failing. Two major instruments, the Cosmic Origins Spectrograph and the Wide Field Camera 3, would be installed.
With the fresh servicing, Hubble could produce unparalleled images for several more years. Without it, the outlook is less bright. Hubble's handlers have developed a "two-gyro" mode of operation that should keep things working until mid-2008, but eventually, the telescope will fall victim to a worn-out guidance system or power system.
NASA Administrator Mike Griffin has ruled out a robotic mission to save the Hubble while leaving the agency's options open for the shuttle rescue scenario. In fact, Hubble's scientists have been told to be prepared for a launch as early as December 2007. Griffin, however, has held off on giving the official go-ahead until the shuttle has a couple of successful test missions under its belt.
That doesn't mean NASA isn't working on the preparations. Shuttle program manager Wayne Hale admitted as much during a news briefing Thursday at NASA's Johnson Space Center in Houston (where I'm currently burning the midnight oil).
"There are some long lead items that are being prepared, based on the assumption that we will be authorized to do a Hubble servicing mission," Hale told me. "The authorization to do that mission has not yet been given, and I think it is dependent on how well we demonstrate our success in the next flight or two.
"Obviously, everybody would like to go back and service the Hubble again, but that is a decision that's ahead of us. And crew assignments are still up in the air."
Hale's comments notwithstanding, there was an intriguing hint last month about the composition of Hubble's repair crew — in the news that astronaut Scott Parazynski was being taken off the STS-118 mission, targeted for launch next year, "to prepare for assignment to another mission."
NASA spokesman Doug Peterson said Parazynski was being shifted to a different not-quite-yet-assignment because of his expertise in spacewalking — but he declined to provide any more specifics about the job. Expert spacewalkers are exactly what you need for servicing the Hubble. So could there be a Hubble angle to Parazynski's pre-reassignment? Drawing that kind of conclusion would be "too futuristic," Peterson told me with a smile.
Yet another "long lead item" could have to do with new techniques for inspecting the shuttle, and that's where the upcoming shuttle mission could play a role. A Hubble servicing job would be the only kind of trip not going to the international space station — which provides the best place in space for inspecting and, if necessary, repairing the shuttle.
During Discovery's mission, the very first spacewalk would be devoted to testing a technique that links together the shuttle's robotic arm and inspection boom to provide a platform for spacewalkers. That would be the only way to give the shuttle a full inspection if you weren't attached to the space station, explained Discovery spacewalker Piers Sellers.
By now I was firmly in the grip of a Hubble-hugging spell, so I asked if this sort of procedure would come into play during a servicing mission. "That's certainly an application," Sellers said. "For Hubble, you would need it for inspection or repair, because there's no one else around."
It turns out that Discovery commander Steve Lindsey said as much in February during an inspection visit to NASA's Kennedy Space Center in Florida.
Something tells me that a final visit to the lonely Hubble would stir up the general public's interest in spaceflight far more than any trip to the international space station. What do you think?
