The Wide Field and Planetary Camera 2, now on display at the Smithsonian's National Air and Space Museum, returned to Earth in May 2009 after more than 15 years in orbit. Eric Long/NASM hide caption

itoggle caption Eric Long/NASM

The presence of water on the moon could enable astronauts to make their own breathing oxygen and to use the moon as sort of a space-based filling station. NASA/AP hide caption

itoggle caption NASA/AP

A team at NASA tests possible maneuvers for the Mars rover Spirit to use to escape the soft soil it has been stuck in since April. NASA/JPL-Caltech hide caption

itoggle caption NASA/JPL-Caltech

Melting at the base of this Texas-sized ice pack in the Amundsen Sea off Antarctica could lead to significant ocean level rise in the long term. This image of the ice shelf was taken on the first flight of Ice Bridge from an altitude of 20,000 feet. NASA hide caption

itoggle caption NASA