The Mercury MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) is a NASA spacecraft designed to survey the planet Mercury from orbit.
The MESSENGER was launched from Cape Canaveral on Tuesday, August 3, 2004. The spacecraft made its first flyby of Mercury in January 2008, and again in October of that year.Official Site: Mission Timeline
During its January flyby, the MESSENGER's cameras transmitted "about 20 percent of the planet's surface missed by Mariner 10," according to its official site. On October 6, the spacecraft captured more high-resolution images, revealing "another 30 percent" of the planet "never before seen by spacecraft."Official Site: Jhuapl.edu
The MESSENGER is scheduled to enter Mercury's orbit in March 2011, where it will start a yearlong "science orbit" of the planet.Official Site: Jhuapl.edu