Session
Technical Session II: Mission Lessons I
Abstract
The Pico Satellite Solar Cell Testbed-2 (PSSCT-2) was a 5” x 5” x 10”, 3.7-kg mass nanosatellite ejected from the Space Shuttle Atlantis during the final STS-135 mission on July 20, 2011. PSSCT-2 had a three-axis attitude control system to enable firing of solid rockets for orbit raising, pointing of solar cells normal to the sun for on-orbit performance monitoring, and pointing of a GPS antenna in the anti-flight direction for radio-occultation measurements. Attitude determination and control hardware developed by the authors for this mission included two sun sensors, an Earth nadir sensor suite, three magnetic torque coils, and three magnetically-shielded miniature reaction wheels. We performed on-orbit magnetic detumbling, nadir-pointing, sun-pointing, flight/anti flight pointing, and crude antenna pointing towards our ground station to support various experiments over the 4 and 1/2-month orbital lifetime. This work discusses the overall mission, attitude sensors, reaction wheel design and testing, magnetic torque coils, attitude control loops, overall performance of our three-axis attitude control system, and some of the lessons learned.
Presentation Slides
Attitude Control on the Pico Satellite Solar Cell Testbed-2
The Pico Satellite Solar Cell Testbed-2 (PSSCT-2) was a 5” x 5” x 10”, 3.7-kg mass nanosatellite ejected from the Space Shuttle Atlantis during the final STS-135 mission on July 20, 2011. PSSCT-2 had a three-axis attitude control system to enable firing of solid rockets for orbit raising, pointing of solar cells normal to the sun for on-orbit performance monitoring, and pointing of a GPS antenna in the anti-flight direction for radio-occultation measurements. Attitude determination and control hardware developed by the authors for this mission included two sun sensors, an Earth nadir sensor suite, three magnetic torque coils, and three magnetically-shielded miniature reaction wheels. We performed on-orbit magnetic detumbling, nadir-pointing, sun-pointing, flight/anti flight pointing, and crude antenna pointing towards our ground station to support various experiments over the 4 and 1/2-month orbital lifetime. This work discusses the overall mission, attitude sensors, reaction wheel design and testing, magnetic torque coils, attitude control loops, overall performance of our three-axis attitude control system, and some of the lessons learned.
