Clementine +20

Clementine - The Mission, Twenty Years Later, Paul Spudis

"In the twenty years following the end of the Apollo program, the lunar science community tried to interest NASA in sending a robotic orbiter to the Moon to map its shape, composition and other physical properties. Such a mission would not only document the processes and history of the Moon, but would also serve as an operational template for the exploration of other airless planetary objects through the collection of global remote sensing data and use of surface samples to provide ground truth."