Hubble telescope's high-tech camera shuts down

Washington, Jan 30: The newest, most high-tech camera aboard the Hubble Space Telescope stopped working last weekend and two of its main capabilities are unlikely to recover, NASA officials said.

The telescope's Advanced Camera for Surveys, meant to take images of huge swaths of the sky, shut down after an electrical short caused a power fuse to fail, the US space agency's Preston Burch said on a telephone news briefing yesterday.

The whole orbiting observatory went into a protective ''safe mode'' at 7:34 am EST (1234 GMT) on Saturday. Hubble returned to regular operation at 2 a.m. EST (0700 GMT) on Sunday, and scientific observation is expected to resume later this week, using instruments besides the survey camera.

''Obviously we're very disappointed by this latest event because of the popularity of ACS with astronomers,'' Burch said.

''The telescope, however, is still a very robust facility and has significant science capability and we will continue to make the best of its capabilities.'' Two of the big camera's elements, or channels, have gone dark and there is no way to repair them short of a mission by space shuttle astronauts.

Such a mission is set for September 2008, but even then, the two powerless channels are unlikely to be fixed, because their power sources make repair cumbersome and time-consuming, and there is a long list of fixes already in prospect for the servicing flight, Burch said.

NEW CAMERA IN 2008

Instead, an instrument developed as a backup for the survey camera will be installed during the repair mission, said David Leckrone, a senior scientist at the Hubble program.

The elements on the survey camera that have stopped working are the wide-field channel and the high-resolution channel, Burch said. A third element, known as the solar blind channel, might be able to be turned back on by mid-February, he said.

The solar blind channel allows scientists to observe very dim cosmic objects by ignoring the light from brighter objects.

Astronomers who proposed research projects using the two dark channels of the survey camera will be asked to determine whether they might do the same research on some of Hubble's other instruments, Burch said.

It is the second electrical problem on the Advanced Camera for Surveys in the last year. An electronics malfunction last June prompted NASA engineers to operate the survey camera on redundant electronics.

The 2008 repair flight will be the fifth since the orbiting telescope's launch in 1990. In addition to installing two new scientific instruments, shuttle astronauts on the 2008 mission are expected to put in new gyroscopes to improve steering, new batteries and thermal blankets to insulate sensitive components.

Reuters