NASA is calling off attempts to find its Deep Impact comet probe after a suspected software glitch shut down radio communications in August, officials said on Friday. The spacecraft was launched in January 2005 for a close-up study of Comet Tempel-1. It was not just a passive experiment. The probe released an 820-pound (372-kg) metal slug that crashed into the comet's nucleus, triggering a shower of particles for analysis by the mother spacecraft and remote observatories. Deep Impact continued its comet quest with a flyby of Hartley 2 in November 2010 and long-distance studies of other bodies, including the approaching Comet ISON. The spacecraft was also used to look for planets beyond the solar system.
NASA last heard from Deep Impact on Aug. 8. Engineers suspect a software problem caused the spacecraft to lose its orientation system, cutting off radio contact with Earth in the process.
After a month of fruitless attempts to find the probe, NASA on Friday announced it was formally ending the mission.
"Despite this unexpected final curtain call, Deep Impact already achieved much more than ever was envisioned," Lindley Johnson, who oversees the program at NASA Headquarters in Washington, said in a statement.
University of Maryland astronomer Michael A'Hearn, who led the Deep Impact science team, said in a separate statement: "I'm saddened by its functional loss. But, I am very proud of the many contributions to our evolving understanding of comets that it has made possible."