Navigation Overview for the Mars Atmosphere and Volatile Evolution Mission

The Mars Atmosphere and Volatile Evolution mission is the first mission devoted primarily to the study of the Martian atmosphere. The spacecraft launched on 18 November 2013, entered Mars orbit on 22 September 2014, and continues to acquire measurements of Mars's upper atmosphere in an effort to understand the loss of Martian volatiles to space. The navigation team is responsible for estimating and predicting the spacecraft's position and velocity, and designing and reconstructing propulsive maneuvers. After Mars orbit insertion, the team faced additional challenges unique to the mission's orbit and tracking data schedule, including the determination of the atmospheric density at each periapsis, which is necessary to keep the spacecraft within a predefined density corridor. This paper briefly describes the Mars Atmosphere and Volatile Evolution mission, shows how it fits into previous and ongoing Mars exploration efforts, and overviews the operations of the navigation team from launch through the nominal science phase.