Finally! NASA Prepares to Orbit Mercury

March 15, 2011: On March 17th, NASA's MESSENGER probe will become the first spacecraft to orbit Mercury. It's a seminal moment in planetary exploration. Researchers can finally take a good long look at a rocky world that is both akin to Earth and shockingly alien. There's just one question: What's taken so long? Mercury is one of the closest planets to Earth and, at first glance, would seem to be readily accessible. Jim McAdams, mission design lead engineer, explains the problem:
"Mercury is going so much faster than Earth that a spacecraft must gain about 65,000 mph to catch it. And once you get there, you're face to face with the searing heat of the sun." Full story here