Scientists are eagerly awaiting a much-needed faceliftplanned for the world?s favorite space telescope.
This fall NASA astronauts plan to take a final space shuttletrip to fix the aging Hubble Space Telescope (HST).
Set to fly Oct. 8 from NASA's Kennedy Space Center (KSC) inCape Canaveral, Fla., the mission will carry seven astronauts aboard theshuttle Atlantis to upgrade the 18-year-old Hubble. Ground crews at KSC are hard at work on repairs to Launch Pad 39A,which suffered damage during the last shuttle liftoff of Discovery on May 31.The work is expected to be finished in time for Atlantis? launch.
?Hubble?s been flying for over 18 years, and although it?sold, there?s still a lot of great science left in this telescope,? said PrestonBurch, HST program manager, at a briefing Tuesday at NASA?s Goddard SpaceflightCenter. ?We believe that [this mission] is going to enable us to finallyunleash the full potential of the Hubble Space Telescope.?
The STS-125 mission will be the fifth trip to repair theorbiting telescope, which has been circling earth about every 97 minutes sinceit launched in April 1990. The planned 11-daymission is slated to install new equipment and repair broken instruments duringfive spacewalks.
New additions
Atlantis is scheduled to deliver the Wide Field Camera 3, whichwas designed to image the distant universe in a broad range of wavelengths, fromnear ultraviolet light through optical light and into the near infrared. Itwill be particularly adept at studying some of the oldest, most distantgalaxies in the universe, whose light has been redshifted to the infraredrange.
?We have no idea what the universe looks like at these veryhigh redshifts,? said Matt Mountain, director of the Space Telescope ScienceInstitute. ?Our first hint will come from Wide Field Camera 3.?
The mission is also due to bring Hubble the Cosmic OriginsSpectrograph (COS), an instrument that can break up light into its constituentcolors to reveal the chemical makeup and other fundamental properties ofheavenly objects.
In addition to the new scientific instruments, Atlantis isset to deliver a set of six new and improved gyroscopes, which help stabilizethe telescope, to replace its old six, three of which are broken. The shuttle missionis also slated to repair some broken instruments aboard the observatory, and bringnew batteries and thermal blankets that should help the telescope operate untilat least 2013.
The crew is also planning to install a docking port called aSoft Capture Mechanism to the observatory. When the telescope is ready to beretired, a future unmanned spacecraft could attach to this device to steer Hubbleon a controlled dive down to Earth and to its demise.
New and improved
NASA hopes the upcomingupgrades will help Hubble have a healthy life for a while yet. To that end,they?ve planned a packed mission to leave the telescope in the best shapepossible.
The numerous activities scheduled for the five busyspacewalking days will be a challenging undertaking, mission managers said.
?Even if we just get one day [of spacewalking repairs] in,we?d have a much better telescope than we have now,? said Keith Walyus, HubbleSpace Telescope Servicing Mission Operations Manager. ?If we get all this done ?wow, that?s going to be absolutely amazing.?
The mission has had a rocky history. Originally cancelled inthe wake of the Columbia disaster in 2003, for a while NASA deemed it too riskyand expensive a venture.
NASA considered sending a robotic repair mission to Hubbleinstead, but eventually decided a manned mission was the only way to accomplishwhat needed to be done.
?The technology they were looking at is amazing,? Walyussaid of the proposed robotic fixes, ?but it?s just not the same as a human.This was built to be worked on by humans.?
Ultimately the strong public and political support for themission helped influence NASA to decide to return to the space telescope onelast time.
?The American people stood up and said wait a minute, not sofast, this is our telescope,? said David Leckrone, Hubble senior projectscientist at Goddard, of the response to the mission?s cancellation.
Beloved by many
The telescope achieves its amazing feats by orbiting 360miles (575 kilometers) above the surface of the Earth, where it bypasses ourplanet's thick atmosphere, which blocks out light and distorts the view fromspace akin to looking at trees from the bottom of a swimming pool.
While Hubble's 2.4 meter (94.5 inch)-wide primary mirrorwould be considered dinky compared to the largest ground-based observatories(the W. M. Keck Observatory in Maua Kea, Hawaii has two scopes with 10-meter,or 400-inch, primary mirrors), in space it is enough to observe the distantcosmos in unmatched detail.
These visions have produced not only groundbreakingscientific discoveries, but also unprecedented enthusiasm from non-scientists.
?When the public saw for the first time the absolute stunningbeauty of the universe we live in, that was a major shift in the way people lookedat the world,? Leckrone said. ?I think there?s a big element of pride on thepart of the American people in having produced Hubble and used it in this way. Ithink as a species we all take collective pride in, hey, this is something wedid, and it was something very hard to do.?
