ExoCube and a Gravity Gradient ADCS
Session
Pre-Conference: CubeSat Developers' Workshop
Abstract
Exocube is a 3U research satellite with a mission to measure various ions and neutrals in the Exosphere. The project is funded by NSF and uses two instruments built by NASA Goddard Space Flight Center. To obtain accurate data, the satellite must maintain very low angular rates and a Nadir pointing less than +/- 10 degrees. Cal Poly designed an attitude determination control system (ADCS) to maintain this pointing requirement throughout the mission. The ADCS is a gravity gradient system with a Kalman Filter, PD controller, and Sinclair momentum wheel. Through simulation, it has been proven that the system will maintain pointing and stability throughout the mission. A camera is integrated on the satellite to provide external verification of the ADCS through derivative imaging of the Earth. Currently, the ADCS is being integrated into hardware for further testing and verification. To further enhance the system, a damper is being designed to be added to the satellite. The goal of this damper is to maintain pointing with the ADCS turned off after stability is reached. This allows all power to be dedicated to the instruments, communications, and the momentum wheel.
Presentation Slides
ExoCube and a Gravity Gradient ADCS
Exocube is a 3U research satellite with a mission to measure various ions and neutrals in the Exosphere. The project is funded by NSF and uses two instruments built by NASA Goddard Space Flight Center. To obtain accurate data, the satellite must maintain very low angular rates and a Nadir pointing less than +/- 10 degrees. Cal Poly designed an attitude determination control system (ADCS) to maintain this pointing requirement throughout the mission. The ADCS is a gravity gradient system with a Kalman Filter, PD controller, and Sinclair momentum wheel. Through simulation, it has been proven that the system will maintain pointing and stability throughout the mission. A camera is integrated on the satellite to provide external verification of the ADCS through derivative imaging of the Earth. Currently, the ADCS is being integrated into hardware for further testing and verification. To further enhance the system, a damper is being designed to be added to the satellite. The goal of this damper is to maintain pointing with the ADCS turned off after stability is reached. This allows all power to be dedicated to the instruments, communications, and the momentum wheel.
