Advanced Flow Control System for In-Space Electric Propulsion

CU Aerospace (CUA) and the University of Michigan (UM) propose the development of the Cycle Automated Mass Flow (CAMFlow) system for reliable and well-regulated flow control. CAMFlow uses an innovative control scheme that enables stable operation using only Boolean valve states, even for the low flow rates necessary for sub-kilowatt Hall effect thrusters. This methodology removes system complexity and places the onus of reliability almost entirely on valve cycle life. The CAMFlow control scheme was successfully implemented in CHIPS, a TRL 5 warm gas thruster produced by CUA through previous NASA SBIR work. As a result, design tools and calculators are already in place for the development and tuning of a system for low flow rate xenon. Phase I and future Phase II CAMFlow units will be focused towards smaller Hall-effect or gridded-ion electric propulsion systems having a flow rate in the 0 ndash; 5 mg/s range, however the technology is broadly applicable over a larger range of flow rates for a broader commercial market. The system will be designed and fabricated with size, functionality, risk tolerance, and cost considerations appropriate for NASA Class-D missions. In Phase I, a breadboard system will be fabricated and tested by CUA, followed by integrated Hall thruster testing and validation at UM. CUA anticipates delivering to NASA an integrated flow control system by the end of Phase II.