MESSENGER - SIX PRIMARY MANEUVERS, SIX PLANETARY FLYBYS, AND 6.6 YEARS TO MERCURY ORBIT

On 18 March 2011, the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) spacecraft became the first probe to orbit Mercury. The spacecraft's 6.6-year journey to Mercury orbit included six large trajectory-correction maneuvers and six planetary flybys. These planetary gravity assists imparted the vast majority of velocity change required to transform the spacecraft trajectory from Earth orbit departure to Mercury arrival. This paper summarizes the design and performance of all planetary flybys and course-correction maneuvers through orbit insertion, as well as the results of targeting the planetary-flyby aim points using the acceleration on the spacecraft imparted by solar radiation pressure.