Reuters: Don Quixote to Ride Again on Cosmic Rescue Mission:
The European Space Agency has given high priority to a Spanish project which aims to attack an approaching asteroid to see whether spacecraft can deflect a body that may in future be on a collision course with earth.
Two craft will set out — one named after the valiant knight of Cervantes’ classic tale, the other after his long-suffering servant Sancho Panza.
Spacecraft Sancho will circle the chosen asteroid while the other — aping its literary namesake — smashes headlong into the target.
The orbiting Sancho and earth-based telescopes will watch closely to see what, if any, effect the impact has on the speed and direction of the asteroid.
At the same time Sancho, being in orbit around the asteroid, will be able to detect fragments thrown from it by the impact and get a glimpse of its internal structure.