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Author
Stone, W. C.
Title
Fast Variable-Amplitude Cold Gas Thruster.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD
Journal
Journal of Spacecraft and Rockets, Vol. 32, No. 2, 335-343, March/April 1995
Keywords
cold gas thruster | amplitude control | piezoelectric stack | structural dynamics | predictive models | system identification
Abstract
A fast response variable amplitude cold gas thruster is described. A laboratory prototype comprised of a piezoelectric stack and an associated microporcessor-based programmable dc power source, a low-loss mechanical displacement amplifier, a high-pressure spring-loaded axial valve, an integral high-pressure valve seat; an expansion nozzle, and a high-pressure gas supply were constructed and tested. The device is designed to operate as a stand-alone unit with a dedicated onboard microcontroller system and onboard energy storage system. Minimum pulse-width resolution (base-to-base) was shown to be 0.98 ms, with a lag time of 0.37 ms relative to the initiation of the drive pulse. Linear amplitude response was achieved beyond a threshold drive voltage of 80 vdc and was maintained through the limit of testing at 240 vdc.