In space exploration, the possibilities for discovery are without limits. Even with the vast amount of knowledge gained since exploration of our solar system began, there are still more questions than answers.

Mariner 10 image mosaic, by Mark Robinson, NWU. Download a large (123K) or a very large (5.2 M) version. Mission News MESSENGER Team Readies for Spacecraft Development Progress continues on the MESSENGER mission, as team members build flight hardware and prepare to integrate parts on the spacecraft this fall. Mercury, the least explored terrestrial planet, is fundamental to understanding the ...

Welcome to the Discovery Acquisition Program | Announcements | AO Mods | AO Clarifications | Discovery Program Library | NASA Privacy Statement Introduction : This Homepage is dedicated to assisting the Discovery community's understanding of the requirements for proposing investigations in response to Discovery Program Announcements of Opportunity (AO's). These AO's can be found in the Research ...