Roamy here. The Deep Impact mission is an interesting example of reusing what you have on hand. (The film, on the other hand, is an interesting example of how stars like Robert Duvall and Morgan Freeman can’t save a story.) In 2005, Deep Impact was launched. As it neared the comet Tempel 1, it separated into two pieces – a probe with cameras and instruments and an impactor that was over 800 lbs. of copper. There shouldn’t be any copper in a comet, so the scientists could eliminate that from the analyses. The impactor smacked into the comet at a relative speed of 10.3 km/sec, kicking up a huge dust cloud.
So the Deep Impact probe did its job, and the data gathered has made for some interesting theories about how comets’ compositions can differ, depending on where they are formed. And…like the THEMIS/ARTEMIS spacecraft discussed earlier, the Deep Impact probe still had some life left in it.
Renamed EPOXI, the probe was sent to rendezvous with Comet Hartley 2.
This comet seems to be a two-fer, where the smooth areas acted like Comet Tempel 1, where water vaporized beneath the surface and percolated out, but the rough areas were shooting out ice particles, like flying through a snowstorm.
NASA is revisiting Comet Tempel 1 in February, but that’s another post.