The Hubble Space Telescope is on track to resume full scientific operations tomorrow night after engineers resolved an 11-day electronics failure of its main camera.
Yesterday, controllers switched to a 15-volt backup power supply serving two of three light detectors on the orbiter's $86 million Advanced Camera for Surveys.
After a thorough engineering study of the failure aboard the observatory, "this turns out to be the best and safest next step," said Ed Ruitberg, acting Hubble project manager at the Goddard Space Flight Center in Greenbelt.
Goddard officials confirmed yesterday that the switchover was successful. A full report on the cause of the breakdown is expected July 24.
The four-year-old ACS is Hubble's "workhorse" camera, providing astronomers with spectacular views of planets, galaxies and some of the most distant objects in the universe.
The still-unexplained failure - in a device Goddard officials likened to the step-down transformer that laptop computer users plug into the wall - delayed up to two dozen scheduled observations. Scientific work using the telescope's three other main instruments was unaffected.
Senior Hubble project scientist David Leckrone said the power supply switchover provided "a little bonus." It enabled engineers to lower temperature settings on Hubble's Wide Field Camera 2, a long-sought adjustment that will make it more sensitive.
The 16-year-old observatory faces more failures in the future as its gyroscopes and batteries age.
Engineers and scientists have been working since last year to find ways to extend Hubble's longevity in case a fifth and final space shuttle servicing mission is scrubbed or delayed by NASA.