NASA's final shuttle mission to overhaul the Hubble Space Telescope has a firm September 2008 launch date, the space agency announced Thursday.
A seven-astronaut crew and the shuttle Atlantis, which currently stands poised for a Friday launch to the International Space Station (ISS), will rocket towards Hubble on Sept. 10, 2008 to give the orbital telescope its fifth and final makeover.
Squeezed in between NASA's remaining shuttle flights to complete space station construction, the STS-125 mission to Hubble will extend the orbital observatory's lifetime through 2013. Without the vital servicing mission, Hubble's major science activities would likely end around 2009, with only basic functions remaining through 2011, Hubble managers have said.
"This is the one mission not going to the space station, so it has to be accommodated on the fitness of Hubble," NASA spokesperson Allard Beutel told SPACE.com of 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 construction schedule."
NASA plans to complete assembly of the ISS by September 2010, when its aging three-orbiter shuttle fleet is due to retire. The space agency initially canceled the final $900 million Hubble servicing mission in 2004, finding the flight too risky after the 2003 Columbia accident.
But wide disapproval of that decision, coupled with support from NASA chief Michael Griffin, led NASA to first study a robotic mission to Hubble before finally returning to the astronaut-based servicing flight aboard Atlantis last October.
As a safety measure, the space shuttle Endeavour is expected to serve as a possible rescue ship should Atlantis suffer critical heat shield damage during launch, Beutel said. Unlike ISS construction flights, in which shuttle astronauts can stay aboard the space station if their orbiter is damaged, the STS-125 crew will not have that safe haven option, NASA officials added.
Commanded by veteran shuttle flyer Scott Altman, the planned 11-day Hubble flight -- known as Servicing Mission-4 -- will feature five spacewalks to refit the orbital telescope.
The STS-125 crew 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 install the Wide Field Camera-3 to enhance the observatory's vision. ?
Hubble researchers have said that they hope the addition of Wide Field Camera-3 will make up for the loss of the observatory's primary camera -- the Advanced Camera for Surveys -- which went offline earlier this year.
The September 2008 servicing mission will be the fifth shuttle flight to overhaul Hubble since the space observatory's April 1990 launch aboard the Discovery orbiter.
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