Sean Solomon, Terrestrial Magnetism’s director, is the principal investigator of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, which is sending the first spacecraft to orbit the innermost planet, Mercury. It’s been a long wait. The craft required an extraordinarily complex trajectory designed to slow it down to the right speed so that it would not bypass the planet and will orbit it instead. MESSENGER was launched in August 2004. The flybys harnessed the gravitational tug of Earth, Venus, and Mercury. The probe has flown by Mercury three times, the latest of which was September 2009. Although it collected a bounty of data from the flybys, the team is anxiously awaiting March 17, 2011, when the tiny craft will finally enter orbit for a year of data collection.Watch the live webcast