Since its launch in August 2004, the MESSENGER spacecraft has traveled 3.04 billion miles (4.89 billion kilometers). That’s the mileage as of January 15, 2009, although it grows about 29 miles (47 km) every second. The October 6, 2008, encounter marked the second flyby of the innermost planet since Mariner 10 skimmed past for its third and final time in 1975.
Message from Mercury
The MESSENGER spacecraft flew past the innermost planet October 6, giving scientists their second close look at Mercury in 2008.