Don Quixote may never have reached the unreachable star, but the Man of La Mancha's namesake (with a modern Spanish spelling) could soon fly to an asteroid. The European Space Agency has chosen two asteroids, designated 2002 AT4 and 1989 ML, one of which will be a target for its Don Quijote mission. The undertaking, to practice deflecting asteroids away from Earth, will send out two spacecraft. The first, the roughly 380-kilogram Hidalgo, named after Don Quixote's noble rank, will impact the chosen asteroid at some 48,000 kilometers per hour. The second, dubbed Sancho after the knight's squire, will rendezvous with and circle the asteroid about six months beforehand to observe the asteroid's orbit before and after Hidalgo's impact. The orbiter will also monitor readings from seismometers it will have deployed on the rock. (Neither 500-meter-wide asteroid is close to crossing Earth's orbit.) The agency will decide which asteroid to attack in 2007, and the mission may depart Earth in 2011.
This article was originally published with the title "Tilting at Asteroids" in Scientific American 293, 6, 36 (December 2005)