Microradian level inertial line-of-sight (ILOS) stabilization with wide-angle search (WAS) capability

Many scientific experiments are planned in this coming decade that require a microradian level inertial-line-of-sight (ILOS) stabilzation with wide-angle search (WAS) capability. A strapped down pointing system configuration consisting of a flexure mounted fast-steering mirror (FSM), bearing mounted gimballed flat mirror, and inertial sensor suite can provide microradian-level stabilization and WAS capability. The FSM, which has limited angular travel up to several degrees, and bandwidths up to 4 KHz, provides fine LOS stabilization; while the bearing mounted gimballed flat mirror provides WAS capability. In this concept, only the LOS is stabilized using a FSM and a gimballed flat mirror, which eliminates the need for a large gimbal and therefore reduces associated weight, power and cost. In addition, this concept has no problems associated with the utility transfer across the gimbal axes, making it very suitable for cryogenic payloads. This paper presents a hardware demonstration of this concept. It shows a three-axes motion table simulating spacecraft motion, and the strapped down pointing system configuration consisting of a FSM, gimballed flat mirror, and an inertial sensor suite.