The main camera on the Hubble Space Telescope, which has revolutionized astronomy with its stunning pictures of the universe, has stopped working, engineers who work on the camera said.

The Advanced Camera for Surveys, a third-generation instrument installed by a space shuttle crew in 2002, went off line last Monday, and engineers are still trying to figure out what happened and how to repair it.

"It's still off line today," Max Mutchler, an instruments specialist at the Space Telescope Science Institute in Baltimore, said on Saturday.

Engineers are hopeful the problem can be fixed, said Ed Campion, a NASA spokesman at Goddard Space Flight Centre outside Baltimore, which is responsible for managing the Hubble.

A bad transistor could be causing the trouble, Campion said. If so, a backup could be used. Another suspicion is that some of the camera's memory was disturbed by a cosmic event. That could be fixed by reloading the memory.

"Both possibilities are things that can be resolved here on the ground," Campion said.

The loss of the camera has not shut down the telescope entirely, he said. "The Advanced Camera for Surveys is regarded as sort of the workhorse for the telescope, but there are other instruments that are still working," Campion said.

The camera sent messages on Monday indicating power supply voltages were above their upper limits and causing it to stop working.

"At this point, the ACS is in a safe configuration, and further analysis is ongoing," according to a statement by the Space Telescope Science Institute.

The Advanced Camera for Surveys consists of three electronic cameras and a complement of filters and dispersers that detect light from the ultraviolet to the near infrared.

Source:China Daily