WASHINGTON, Jan. 16 (UPI) -- NASA administrator Sean O'Keefe decided Friday to cancel a previously planned space shuttle mission to repair and upgrade the Hubble Space Telescope, United Press International has learned.
The decision effectively condemns the Hubble -- which has been operating since 1990 -- to mechanical failure sometime in the next few years.
The mission, called SM4 -- representing the fourth shuttle visit to the Hubble since its launch in 1990 -- had been planned for sometime in 2005, after NASA resumed flights of the space shuttle fleet. The remaining three orbiters have been grounded since last Feb. 1, when shuttle Columbia disintegrated during its attempted re-entry into the atmosphere.
According to an internal NASA memo obtained by UPI, O'Keefe's decision was made for safety reasons and not budgetary concerns. Nor was the new space initiative, announced on Jan. 14 by President George W. Bush, a factor in the decision.
If NASA manages to overcome shuttle safety concerns and return the spacecraft to flight, agency officials have decided to confine all remaining shuttle missions to rendezvous with the International Space Station. Such missions would offer shuttle crews the option, in an emergency, of remaining aboard the station until a rescue craft could be dispatched.
This strategy, which was recommended by the Columbia Accident Investigation Board, could not have prevented the deaths of the Columbia astronauts, however, because its orbit would not have allowed it to dock with the station.
A shuttle flight to the Hubble would not offer the safe harbor option as a visit to the station.
The 2005 mission to Hubble was supposed to supply the telescope with gyroscopes to replace the two currently malfunctioning, plus any others in need of replacement. Hubble carries a total of six gyroscopes and can perform its scientific missions with as few as three in operation. NASA estimates the chances of three gyroscopes remaining functional by July 2006 at only 30 percent. Any further failure would severely limit Hubble's ability to carry out meaningful science.
The mission also was supposed to deliver a new wide field camera and spectrometer. According to NASA's memo, officials now will examine options for using the instruments on satellites.
Last July, NASA scientists had gathered to discuss the future of the Hubble, which has become world famous for its ability to photograph distant galaxies and astronomical phenomena. Next year's planned servicing mission was seen as a way to extend the telescope's useful life for five or so years, until the next generation, Webb Space Telescope, was scheduled to become operational, in 2010.
NASA's plans for returning the Hubble to Earth remain incomplete at this time, but likely would involve attaching an unmanned rocket to the telescope to steer it to a fiery death in Earth's atmosphere.
Keith L. Cowing is editor of nasawatch.com. E-mail firstname.lastname@example.org