LOW COST THRUST VECTOR CONTROL SYSTEM DEVELOPMENT FOR SMALL LAUNCH VEHICLES

While many organizations have been involved in the development of nanosatellites, relatively few of them have focused on the development of small launch vehicles (SLVs) dedicated for such payloads. One of the key capabilities for such SLVs is cost-effective thrust vector control. This paper presents the status of an on-going effort addressing this requirement which is being implemented within the framework of the California Launch Vehicle Education Initiative (CALVEIN). The CALVEIN team, which is based on a cooperative partnership between California State University, Long Beach (CSULB) and Garvey Spacecraft Corporation, plans to demonstrate initial TVC concepts by using the school's Prospector-3 (P-3) prototype vehicle to perform a pitch maneuver and return to straight flight. Electro mechanical actuators (EMA) gimbal the 500 lbf engine in two axes for pitch and yaw control. An onboard computer processes inputs from the three rate gyros and commands the EMA's to guide the rocket along the predetermined flight path. Analysis of the vehicle dynamics and control algorithm shows that the TVC system developed is stable with adequate margins. The system was successfully static fire tested on Sept 22 nd , 2002. P-3 was flown in open loop on Feb 22 nd 2003 and demonstrated in-flight thrust vectoring. At least two additional flights are planned with P-3 to complete the development and test of the guidance, navigation and control as well as telemetry systems.