NASA's Mars Reconnaissance orbiter reaches the planet. It has sent back more data than all other missions combined.

NASA/JPL/AP
This artist's rendering released March 8, 2006 by NASA's Jet Propulsion Laboratory shows the Mars Reconnaissance Orbiter near Mars. The NASA spacecraft successfully slipped into orbit around Mars Friday, March 10, 2006, joining a trio of orbiters already circling the Red Planet after a critical firing of its engines.