Last week NASA reported with pride that Voyageur 1 was still going strong after more than thirty years in space, and became the first man made object to leave the solar system. This week comes less joyful news that the Deep Impact probe has been formally declared to be dead.

Deep Impact was launched on a Delta II rocket on January 12, 2005 with the goal of performing several fly-bys of nearby comets. The first target was Comet Tempel 1, which was extensively photographed in July 2005, before the Deep Impact probe launched its most interesting experiment - a 370 kg copper-core impactor that it sent towards the comet resulting in a massive collision. The orbiting part of the probe then imaged and analyzed the resulting debris cloud, with the goal of studying the chemical contents of the comet. 

Scientists reported an unexpected result when they found that the debris created by the impact contained more dust and less ice than expected. The spectroscopic analysis of the impact revealed evidence of  different clays, carbonates, sodium, and crystalline silicates, and an unexpected high quantity of organic molecules. 

In addition to the formal studies, this experiment also took advantage of public interest and the amateur astronomy community. Since the large telescopes are in constant use for a variety of scientific projects, the Deep Impact team encouraged amateur astronomers to image the comet from the ground, and by the end of the mission over a thousand CCD images had been submitted for analysis.

That was the nominal end of the Deep Impact mission - but the probe was still in good shape and the engineers were able to set a new trajectory that would take it to another comet. The next comet in line was Comet Boethin in 2008, but unfortunately after the course was setup astronomers found the comet had disappeared - probably broken up into small fragments. In November 2010, the Deep Impact probe flew by its third target, Comet Hartley 2, and returned images of its core. By the spring of 2012, Deep Impact had reached a fourth target, Comet Garradd and found it to be composed of water and dry ice, and ejecting gas at a periodic rate. The following February the probe did a fly by of Comet ISON, returning more data to the Earth based scientists, before being directed to a comet further out in the solar system.

Unfortunately in August the team lost contact with Deep Impact, and this week they have been forced to admit that it is probably dead. They are no longer trying to communicate with it, and suspect that it has gotten turned around in such a way that its solar panels are no longer recharging its battery. So unless there is a sudden miracle, the probe is probably at the end of its life. However considering it went from a one-comet mission in 2005 to a five comet study over eight years, it certainly cannot be considered a failure!