How do you orbit Mercury?

Well, you start with a launch from earth, make 15 trips around the sun, including passing Earth once, Venus twice, and Mercury three times for a total of 4.9 billion miles before settling into orbit almost seven years later. Of course, that depends on when you launch. NASA waited 2 1/2 months for another launch window in 2004 and that added two years to the trip. Today Messenger is making its first pass of Mercury, about halfway through its trip. I've been watching From Earth to the Moon lately so calculating flight paths has been on my mind.