At 8:45 PM EDT, March 17, 2011, the tiny MESSENGER craft began its successful burn to make it the first spacecraft in history to orbit the innermost planet Mercury.Carnegie's Sean Solomon is the principal investigator. At about 10:00 PM engineers in the MESSENGER Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., confirmed that the craft made a “perfect” transition into orbit, where it will begin a year of science observations in a few weeks. See APL press release