NASA's finalshuttle mission to overhaul the Hubble Space Telescope has a firm September2008 launch date, the space agency announced Thursday.
Aseven-astronaut crew and the shuttle Atlantis, which currently stands poisedfor a Friday launch to the International Space Station (ISS), will rockettowards Hubble on Sept. 10, 2008 to give the orbital telescope its fifth andfinal makeover.
Squeezed inbetween NASA's remaining shuttle flights to complete space stationconstruction, the STS-125 mission to Hubble will extend the orbital observatory'slifetime through 2013. Without the vital servicing mission, Hubble's major scienceactivities would likely end around 2009, with only basic functions remainingthrough 2011, Hubble managers have said.
"Thisis the one mission not going to the space station, so it has to be accommodatedon the fitness of Hubble," NASA spokesperson Allard Beutel told SPACE.comof the September 2008 launch date. "This gives us the time to be able to do that while at the same time fitting it into the space station constructionschedule."
NASA plansto complete assembly of the ISS by September 2010, when its aging three-orbitershuttle fleet is due to retire. The space agency initiallycanceled the final $900 million Hubble servicing mission in 2004, findingthe flight too risky after the 2003 Columbia accident.
But widedisapproval of that decision, coupled with support from NASA chief MichaelGriffin, led NASA to first study a robotic mission to Hubble before finally returningto the astronaut-basedservicing flight aboard Atlantis last October.
As a safetymeasure, the space shuttle Endeavour is expected to serve as a possible rescueship should Atlantis suffer critical heat shield damage during launch, Beutelsaid. Unlike ISS construction flights, in which shuttle astronauts can stayaboard the space station if their orbiter is damaged, the STS-125 crew will nothave that safe haven option, NASA officials added.
Commandedby veteran shuttle flyer Scott Altman, the planned 11-day Hubble flight --known as Servicing Mission-4 -- will feature five spacewalks to refit theorbital telescope.
The STS-125crew is expected to: repair one of Hubble's spectrographs and install another;boost the space telescope's orbit; overhaul its attitude control system,replace batteries, thermal insulation and a broken guidance sensor; and installthe Wide Field Camera-3 to enhance the observatory's vision. ?
Hubble researchershave said that they hope the addition of Wide Field Camera-3 will make up forthe loss of the observatory's primary camera -- the Advanced Camera for Surveys-- which wentoffline earlier this year.
The September2008 servicing mission will be the fifth shuttle flight to overhaul Hubblesince the space observatory's April 1990 launch aboard the Discovery orbiter.
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