Development of Gimbaled Laser Beacon Mechanism

The Photon Satellite Project is being sponsored by the Florida Space Institute (FSI). FSI is working on the Conceptual Design Phase for this project under a contract from the Department of Defense Ballistic Missile Defense Organization. The science mission for this satellite is to characterize the atmospheric effects on a laser communications system. The development of a gimbaled laser beacon mechanism focuses on the secondary payload of that science mission, which serves as a downlink of laser signals from space to the ground station located at the Innovative Science and Technology Experimental Facility (ISTEP) at the Kennedy Space Center. This paper focuses on the development and design of a gimbaling system for a collimated laser diode beacon. The design will include selection of optics, motors, bearings, structural design, development of the equations of motion and the control design. The main objective of gimballing the beacon is to maximize the communication time with the ground station allowing pointing capabilities to be focused and pointed at the ground station over the entire satellite pass from horizon to horizon. This will allow the laser intensity to be increased and allow visibility whether the pass is a daytime or nighttime pass