ATTITUDE CONTROL AND ESTIMATION ACTIVITIES DURING COMMISSIONING OF THE TWIN VAN ALLEN PROBES SPACECRAFT

摘要

The Van Allen Probes were launched into Earth orbit on August 30, 2012 for a nominal two-year mission to study the Earth's radiation belts and their interaction with the Sun. The two spin-stabilized spacecraft have onboard Guidance and Control hardware consisting of Sun sensors, passive nutation dampers, and eight mono-propellant hydrazine thrusters. Magnetometer data are provided by a science instrument. Attitude estimates and open-loop maneuver designs are generated on the ground. During the first 60 days of commissioning the Guidance and Control team designed and executed a total of 24 maneuvers, performed calibrations of the Sun sensors, thrusters, and magnetometers, computed changes in spacecraft moments of inertia through various spacecraft solar array panel and instrument boom deployments, and better characterized the dynamical behavior of the twin spacecraft in their highly elliptical orbits. This paper describes the Van Allen Probes spacecraft, the attitude estimation and control activities conducted during the first 60 days of commissioning, and the performance of the spacecraft and ground software throughout this period of time.