Walter Watts
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Hubble Telescope Loses Its Survey Camera (This just bums me out no end)
« on: 2007-01-29 21:13:11 » |
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This just bums me out no end.
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The New York Times
January 29, 2007
Hubble Telescope Loses Its Survey Camera
By DENNIS OVERBYE
The Hubble Space Telescope is flying partially blind across the heavens because of a short circuit in its most popular instrument, the advanced camera for surveys.
NASA engineers reported today that most of that camera’s capabilities — including the ability to take the sort of deep cosmic postcards that have inspired the public and to track the mysterious dark energy splitting the universe to the ends of time — have probably been lost for good.
In a telephone news conference from NASA headquarters, Hubble engineers and scientists said the telescope itself was in fine shape and would continue operating with its remaining instruments, which include another camera, the wide-field planetary camera 2, or wfpc2, and an infrared camera and spectrograph named Nicmos. The advanced camera for surveys stopped working Saturday morning.
“Obviously we are very disappointed,” said Preston Burch, program manager for the telescope, of the Goddard Space Flight Center in Greenbelt, Md., noting that the camera had basically met its five-year design lifetime. The Hubble telescope, he said, still has significant science capability.
He and his colleagues said that it was unlikely they would be able to repair the camera during the next Hubble servicing mission, which is scheduled for September 2008. On that mission, astronauts will replace the existing wide field camera with a powerful new version, wfpc3, which will extend Hubble’s vision to ultraviolet and infrared wavelengths and restore the lost capabilities. They will also install a new ultraviolet spectrograph, among many pressing repairs.
Noting that the five days of spacewalks are already full and that changing things to fix the camera would cost time and money, Dr. Burch said, “At first blush, this doesn’t look attractive.”
The Advanced Camera for Surveys was installed on the telescope in March 2002, and it has been Hubble’s workhorse ever since. Among its other feats, in 2003 camera took the deepest photograph of the cosmos ever taken, the Hubble Ultra Deep Field, showing young galaxy fragments only one billion to two billion years after the Big Bang. In the most recent round of proposals from astronomers to use the Hubble, about two-thirds of them required the advance camera.
The camera had been operating on its backup electrical system since last summer, however, when electrical problems in its main system caused it to shut down for a while. Now the backup system has failed, dooming its ability to take wide-field or high-resolution images.
The camera might yet be operated in what the engineers called “solar blind mode,” at ultraviolet wavelengths to observe phenomena like auroras on Jupiter.
The electrical problems did not apparently spread to the rest of the telescope. Rick Howard, of NASA headquarters, said, “The fuse did what it was supposed to do. It saw a high current and it popped. It protected the rest of the telescope.”
Astronomers said that the Space Telescope Science Telescope Institute had developed a contingency plan of observations that could go on without the advanced camera for surveys and that there was no shortage of astronomers who would want to use it. But some of Hubble’s most crucial and high-visibility programs will be delayed.
Adam Riess of space telescope institute, who has used Hubble to search for supernova explosions in the distant universe in order to gauge the effects of dark energy on cosmic history, said these explosions would now be out of reach until the new camera was installed.
Still, he said in an e-mail message, it was a great camera. “Although it only lasted 4.9 years, it was only rated for 5 years, so we really got our money’s worth,” he said.
Copyright 2007 The New York Times Company
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