September 13, 2013 - A veteran NASA
comet-chasing probe has stopped communicating with mission
managers and is apparently spinning out of control.
The robotic spacecraft, that was sent to Comet Tempel 1
to carry out a historic bombing run with a washing machine-sized 370 kilogram (820 lb) impactor on July 4, 2005, was originally called Deep Impact, but had its mission extended to continue solar system exploration after its cometary encounter and renamed Extrasolar Planet Observation and Deep Impact Extended Investigation, or EPOXI. Scientists of the University of Maryland manages the EPOXI
After the 2005 comet encounter, EPOXI
completed an Earth flyby and was sent to travel past another icy body, Comet
Hartley 2, in 2010, recovering high resolution images of the comet's nucleus. The mission was then tasked with another, more distant, observation of Comet
Garradd in 2012. Most recently, the spacecraft was commanded to track the incoming Comet
ISON, recovering the first images in January. In 2008, a component of the EPOXI
mission (called the Extrasolar Planet Observation and Characterization, or EPOCh) was also used to characterize observations of previously discovered extrasolar planets orbiting other stars.
But it seems that the EPOXI
mission may have come to an end.
In a mission update on Sept. 3, EPOXI
lead scientist Michael A'Hearn
said, "We have not received any of our expected observations of comet ISON due to a spacecraft problem. Communication with the spacecraft was lost some time between August
11 and August 14 (we only talk to the spacecraft about once per week). The last communication was on August 8. After considerable effort, the team on August 30 determined the cause of the problem. The team is now trying to determine how best to try to recover communication."
According to a Nature News blog report on Sept. 5, A'Hearn added that his team were unable to upload commands to EPOXI
to switch it into a safe mode. The probe is now thought to be spinning out of control, severely impacting its ability to generate energy through its solar array. Although engineers have identified the problem as being a computer glitch and are working to revive the mission, it is thought the probe only has a matter of days until its batteries are drained. Once that happens, the spacecraft will be unrecoverable.
"How long we have depends on the state the spacecraft is in, and we don't yet know that," A'Hearn told SPACE.com on Monday (Sept. 9). "Could be that it is too late already - could be we have another month or more."