Sky
and Telescope: The Hubble Space Telescope's main camera is
back online, almost two weeks after a problem with its power
supply forced it into safe mode. The camera was fixed when
engineers at NASA's Goddard Space Flight Center switched the
$86-million Advanced Camera for Surveys (ACS) to its backup
electronics.The shutdown has given NASA an opportunity to
recalibrate the camera's CCD sensors to operate at a slightly
lower temperature ( â77°C to
â81°C). This should reduce the amount of
background noise in the images by a factor of three.
