MESSENGER GUIDANCE AND CONTROL SYSTEM PERFORMANCE DURING INITIAL OPERATIONS

摘要

Flight operations are finally underway for the MESSENGER - MErcury Surface, Space ENvironment, GEochemistry, and Ranging - mission. As part of NASA's Discovery program, the spacecraft will observe Mercury during flybys in 2008 and 2009 and from orbit for one Earth-year beginning in March of 2011. The guidance and control system combines extensive flight software with various sensors and actuators to maintain a 3-axis stabilized spacecraft and to implement desired velocity changes. The spacecraft was successfully launched on August 3, 2004, immediately putting the guidance and control system to the test. Initial mission events described in this paper are detumble after separation from the launch vehicle, attitude control for the initial Sun-relative rotation and in the later 3-axis inertial attitude mode, and the first trajectory correction maneuvers.