Academies Weigh Mission Options
After 14 years of service and 650,000 amazing images of the solar system and the far reaches of the universe, the Hubble Space Telescope is starting to lose power. By replacing its batteries and some of its key instruments, the telescope could go on providing stunning images until at least 2010. After the 2003 crash of the space shuttle Columbia, however, NASA immediately grounded the shuttle fleet until the agency could determine the cause of the accident and take measures to prevent it from happening again.
This put the Hubble telescope's future in jeopardy. To reach its full potential and operate for 15 to 20 years, the telescope needed to be serviced by several space shuttle missions. Four have already occurred, on which shuttle crews replaced some of the telescope's instruments and upgraded the resolution of its cameras.
At first, the Columbia accident left a fifth mission in limbo, but in January 2004, NASA Administrator Sean O'Keefe announced its cancellation due to safety risks. This prompted a groundswell of criticism from astronomers, the public, and Congress, arguing vehemently that Hubble was worth saving. Sen. Barbara Mikulski, D-Md., whose district includes the Space Telescope Science Institute and the Goddard Space Flight Center, requested an independent assessment of the risk associated with a shuttle servicing mission to Hubble. O'Keefe asked the National Research Council to take on this task.
In early June, O'Keefe announced that NASA would pursue proposals regarding the feasibility of a robotic mission. NASA started developing a robotic mission that would be capable of replacing aging batteries, fine-guidance sensors, gyroscopes, and two scientific instruments, as originally planned for in the fifth shuttle mission.
However, the National Research Council committee charged with examining options for extending the life of the telescope called on NASA to send a manned mission, not a robotic one, to save Hubble. The agency should consider launching the shuttle mission as early as possible -- at least before 2008 -- after the space shuttle is deemed safe to fly again, because some of the telescope's components could soon degrade to the point where it would no longer be usable, the committee said issuing its final recommendations in December.
"A shuttle servicing mission is the best option for extending the life of the Hubble telescope and ultimately de-orbiting it safely," said committee chair Louis J. Lanzerotti, distinguished research professor at the New Jersey Institute of Technology, Newark, and consultant, Bell Laboratories, Lucent Technologies, Murray Hill, N.J. "NASA's current planned mission is significantly more technologically risky, so a robotic mission should be pursued only for the eventual removal of the Hubble telescope from orbit, not for an attempt to upgrade it."
The committee's principal concerns about a robotic mission are the risk of failing to develop it in time and the risk of a mission failure, as well as the possibility that a robot could critically damage the telescope.
It now seems that the telescope might not be rescued at all. In its fiscal year 2006 budget proposal recently submitted to Congress, the Bush administration deemed any proposal to upgrade the orbiting telescope too costly and did not include the funding necessary for such upgrade. If upheld by Congress, NASA's budget could sound the death knell for a telescope that for nearly 15 years has been shedding light on previously unknown parts of the universe.
-- Patrice Pages
Assessment of Options for Extending the Life of the Hubble Space Telescope -- Final Report. Committee on the Assessment of Options for Extending the Life of the Hubble Space Telescope, Division on Engineering and Physical Sciences (2005, 160 pp.; ISBN 0-309-09530-1; available from the National Academies Press, tel. 1-800-624-6242; $32.50 plus $4.50 shipping for single copies).
Louis Lanzerotti, distinguished research professor at the New Jersey Institute of Technology, Newark, and consultant, Bell Laboratories, Lucent Technologies, Murray Hill, N.J., chaired the committee. The study was funded by NASA.