Goals: Mars Odyssey is an orbiter carrying science experiments designed to make global observations of Mars to improve our understanding of the planet's climate and geologic history, including the search for water and evidence of life-sustaining environments.

Accomplishments: Mars Odyssey provided stunning images and crucial science far beyond its planned 917-day mission. The orbiter made valuable global observations of Martian climate, geology and mineralogy. It mapped the elemental distribution of hydrogen, silicon, iron, potassium, thorium and chlorine on the Martian surface. Odyssey also determined that radiation in low-Mars orbit -- an essential piece of information for eventual human exploration because of its potential health effects -- is twice that in low-Earth orbit.

The orbiter's maps helped guide the selection of landing sites for the Mars Exploration Rover Opportunity and the Phoenix polar lander.