On Orbit Jitter Simulation Testing of the Clementine Spacecraft

The Clementine Spacecraft was launched on January 25, 1994 from Vandenberg Air Force Base. The spacecraft was designed, fabricated and tested by the Naval Research Laboratory (NRL). It used an array of lightweight optical sensors to perform the most extensive mapping of the lunar surface to date. Satisfactory operation of the sensors depended on having structure borne vibration kept within predetermined requirements. These requirements included angular displacement and angular velocity levels that could not be exceeded without blurring the sensor images. Testing was performed at the Naval Research Lab in which sources of on orbit vibration were simulated and the resultant acceleration responses measured on the sensor mounting panel (Sensor Bench). These acceleration responses were then transformed into the required format and evaluated with respect to the maximum allowable jitter for each sensor. Where applicable, vibration sources were operated over a range of operating parameters such as solar array rotation speed and thruster pulsing were determined. This paper discusses novel test techniques that were employed to simulate, measure and evaluate these dynamic parameters.