NASA Deep Impact: Team attempts to restore communications

Artist's concept of NASA's Deep Impact spacecraft. 

Credit: NASA/JPL-Caltech

Ground controllers have been unable to communicate with NASA's long-lived Deep Impact spacecraft. Last communication with the spacecraft was on Aug. 8, 2013.

Deep Impact mission controllers will continue to uplink commands in an attempt to reestablish communications with the spacecraft.

Mission controllers postulate that there was an anomaly generated by the spacecraft's software which left the vehicle's computers in a condition where they are continuously rebooting themselves.

If this is the case, the computers would not continue to command the vehicle's thrusters to fire and hold attitude.

Lack of attitude hold makes attempts to reestablish communications more difficult because the orientation of the spacecraft's antennas is unknown.

It also brings into question the vehicle's electrical power status, as the spacecraft derives its power from a solar array that is fixed, with its cells pointing in one direction.

Deep Impact is history's most traveled deep-space comet hunter. It successfully completed its original mission and a subsequent extended mission.

NASA Deep Impact: Contact With Comet-Hunting Spacecraft Lost

An artist's conception show's a close-up look at NASA's comet-hunting Deep Impact spacecraft.

Credit: Nasa

NASA's veteran Deep Impact probe may have chased its last comet.

The spacecraft's handlers lost contact with Deep Impact — which slammed an impactor into Comet Tempel 1 in 2005, made a close flyby of Comet Hartley 2 in 2010 and recently observed ISON, a "comet of the century" candidate — sometime between Aug. 11 and Aug. 14, mission team members announced last Tuesday (Sept. 3).

"The last communication was on August 8. After considerable effort, the team on August 30 determined the cause of the problem," principal investigator Mike A'Hearn of the University of Maryland wrote in a brief mission update Tuesday.

"The team is now trying to determine how best to try to recover communication."



The issue stems from a software glitch that reset Deep Impact's computer, A'Hearn told reporters at prestigious scientific journal Nature.

Things are serious, he added: Deep Impact is apparently spinning out of control after recent attempts to put the probe into hibernation mode were unsuccessful.

It's unclear how much time the mission team has to bring Deep Impact back in line. Depending on how the probe's solar panels are oriented, Deep Impact's batteries could run out of juice in a matter of days or keep going for several months.

"How long we have depends on the state the spacecraft is in, and we don't yet know that," A'Hearn told reporters. "Could be that it is too late already — could be we have another month or more."

Deep Impact launched in January 2005 on a mission to rendezvous with Comet Tempel 1. In July of that year, the spacecraft sucessfully smashed an impactor into Tempel 1, allowing scientists to study the icy object's composition.

NASA Deep Impact Probe Snaps Photos of Comet ISON

The comet that may put on a spectacular light show during a November date with the Sun, was observed by the Deep Impact mission. The spacecraft has also had close fly-bys of comet's Tempel 1 and Hartley 2 and scientific observations of Garradd.

CREDIT: NASA/JPL-Caltech/UMD (Tony Farnham)

A NASA spacecraft has captured its first photos of comet ISON, an icy wanderer that some scientists say could dazzle as a "comet of the century" when it swings through the inner solar system later this year.

The photos were taken by NASA's Deep Impact probe and reveal comet ISON as a bright, dusty ball moving against a star-filled background. The spacecraft snapped the pictures on Jan. 17 and Jan. 18 from a distance of about 493 million miles (793 million kilometers).

Comet ISON has been the focus of much anticipation among scientists and stargazers because of its potential to put on a spectacular display in late November, when it makes its closest approach to the sun.

Some forecasts predict the comet could shine brighter than the full moon. As of mid-January, the comet's tail was more than 40,000 miles (64,400 km).

Some projections state that comet ISON, which is officially designated comet C/20012 S1 (ISON), could shine extremely bright in the nighttime sky, possibly even rivaling the full moon.

Whether the comet will meet expectations or fizzle out remains to be seen, but it has already become a target for NASA and amateur astronomers.

"This is the fourth comet on which we have performed science observations and the farthest point from Earth from which we've tried to transmit data on a comet," Deep Impact project manager Tim Larson, of the agency's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement Tuesday (Feb. 5) "The distance limits our bandwidth, so it's a little like communicating through a modem after being used to DSL. But we're going to coordinate our science collection and playback so we maximize our return on this potentially spectacular comet."