The Discovery Program is a NASA program of small probes which originally operated under the rubric "faster, better, cheaper." The first four missions to be launched – Near Earth Asteroid Rendezvous, Mars Pathfinder, Lunar Prospector, and Stardust – all had some astrobiological interest. Basic requirements of the Discovery Program is that missions should take less than 3 years to complete in order that they can take advantage of the latest technology. The latest mission in this series is GRAIL.