Astronomers Debate Hubble’s Future
by TONY REICHHARDT
Squabble over scarce NASA dollars informs panel deliberations.
Nature — Leading astronomers clashed in Washington DC last week over when or whether to shut down the Hubble Space Telescope.
NASA wants to decommission Hubble in 2010, primarily to divert money to the bigger and better James Webb Space Telescope (JWST), set to launch in 2011. A growing number of astronomers want it to keep going at least until JWST is launched.
Hubble has been orbiting 600 kilometres above Earth’s surface since 1990. From beyond our distorting atmosphere, it gives scientists an unrivalled view of galaxies near and far.
The Washington DC meeting will influence the deliberations of an expert panel, led by John Bahcall of the Institute for Advanced Study in Princeton, New Jersey, set to report to NASA in October.
Until recently, the agency had planned to have the space shuttle return Hubble to Earth for museum display. “No one wants to do that anymore,” says Anne Kinney, head of NASA’s astronomy and physics division.
In fact, the US astronaut corps opposes “risking human lives for the purpose of disabling great science” representative John Grunsfeld told the meeting. It would support a servicing mission to extend Hubble’s life or ensure its safe re-entry, he said.
A servicing trip to the telescope costs NASA about US$700 million, much of which maintains planning teams at the Goddard Space Flight Center in Greenbelt, Maryland.
The option of moving the Hubble to a higher storage orbit has also been dropped. Instead, NASA favours attaching a rocket booster to the telescope in 2010 to steer it to burn up over the ocean.
So far, NASA has found no affordable way to attach the rocket and extend the telescope’s life without degrading its performance. Defenders argue that the problem can be solved, and that useful observations can still be obtained from the telescope after the booster is attached.
For a little extra money, they argue, NASA could even add research instruments during the mission to attach the de-orbit package. New cameras and detectors should improve the telescope’s performance tenfold for selected observations.
But JWST scientist George Rieke, of the University of Arizona in Tucson, warned against spending scarce NASA funds on improving Hubble’s capabilities to survey distant galaxies when “we’re building another instrument to do that even better”.
JWST will be more sensitive than Hubble, but will lack its unique ability to survey across visible, ultraviolet and infrared wavelengths. A
stronomers viewing in X-rays and gamma rays “are terribly dependent” on supporting data from Hubble, said Nobel laureate Riccardo Giacconi, a former director of the Space Telescope Science Institute in Baltimore, Maryland.
Indeed, members of the US Association of Universities for Research in Astronomy rank continued space-based observations in visible and ultraviolet wavelengths as their highest priority.
Hubble is much more productive than past telescopes that NASA has shut down, said John Huchra, chair of the association’s directors: “It’s the Energizer Bunny of astronomy”.
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