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More problems with Hubble

Hubble’s resurrection is suspended while engineers examine two anomalies

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4:49pm, October 17, 2008
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Two anomalies onboard the orbiting Hubble Space Telescope, which stopped transmitting data on September 27, caused engineers to suspend re-activation of Hubble’s science equipment. Engineers encountered problems following an intricate maneuver to circumvent a piece of failed hardware. Hubble is currently orbiting Earth in a dormant “safe mode” while the malfunctions are assessed.

In an October 17 teleconference, NASA scientists said that it is too soon to know the details of the failures. “We are in the early stages of going through a mountain of data that has been downloaded,” said Art Whipple, manager of the Hubble Systems Management Office at NASA’s Goddard Space Flight Center in Greenbelt, Md., at the teleconference. “This is a marathon, not a sprint.”

These latest anomalies came at a critical time, during the team’s attempt on October 16 to wake up all of Hubble’s science equipment and restore the orbiting telescope to full science capabilities.

The late September failure in Hubble’s science data formatting unit halted all science data communications to Earth. Since then, Hubble has been orbiting Earth silently, performing only basic health and safety functions, with almost all of its science observations suspended.

On October 15, engineers attempted to restore the stream of science data by switching operations from the damaged “A” side of the unit to a duplicate backup device called side “B.” Early indications were positive: Key instruments including the Advanced Camera for Surveys, the Wide Field and Planetary Camera 2 and the Near Infrared Camera and Multi-Object Spectrometer successfully communicated through the “B” side for a brief moment before engineers returned them to their quiescent state.

But on October 16, system monitors indicated that a power supply to the Solar Blind Camera failed to reach the correct level, and another, yet-unidentified problem may have occurred, causing sensors to send Hubble into “safe mode.”

MattMountain, director of the Space Telescope Science Institute in Baltimore, says the latest developments are disappointing, since the team had hoped for a clean switch to the redundant “B” side.

It is too early to rule out any possible causes of the new malfunctions, including the switch from the “A” to the “B” side, says Whipple.

The team is not out of ideas, though. A potential contingency plan of using a hybrid of the “A” side and the “B” side of the data processor may solve the problem. The Hubble team successfully tested this maneuver on a replica of Hubble that is housed in a clean room at Goddard. “This is one of the contingency cases we had thought about ahead of time,” says Whipple.

“So far — touch wood — we are not out of options to get HST back on the air,” says Mountain.

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