WASK Engineering proposes to refine the design of an piezo actuated throttling valve fabricated in Phase 1 that has demonstrated the ability to open within 2.6 msec to meet the requirements of a 100 lbf RCS thruster. This includes verifying the valve cycle life and valve leakage amounts. Similar valves designed by WASK Engineering have operated for more than 2x109 cycles while maintaining a leakage rate of less than 1x10-3 sccm of He. The current valve design is configured to operate with cryogenic propellants and support the flow rates requried for a 100 lbf liquid oxygen/liquid methane thruster. A piezo actuated valve has many benefits for RCS thrusters. The speed with which the valve can adjust its throttle position means that with two such valves the thruster propellant mixture ratio can be rapidly adjusted to preventhardware damage. The valves have the ability to continuously throttle over a range of thrust levels, allowing the thruster to operate from zero to full thrust. The piezo crystals use very little power, reducing the overall power consumption, again reducing weight.
Potential NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) Potential NASA applications include extremely durable, high-performance, low cost RCS systems for manned space flight to support high performance propulsion requirements such as orbit transfer, descent, ascent and pulsing attitude control. The ability to throttle makes the control very effective, as the impulse bit can be adjusted from large to very small depending on the immediate requirement. This has the benefit of simplifying the control system due to the very small minimum impulse bit possible. These valves can also be used as propellant valves for small monopropellant and bipropellant thrusters. This is especially the case if throttling is desired in the thrusters.
Potential NON-NASA Commercial Applications:
: (Limit 1500 characters, approximately 150 words) The valve is applicable for propellant flow control to both cryogenic and non-cryogenic thrusters. We are already in discussions with a potential customer for application of the valve developed in the Phase 1 effort to gaseous RCS thrusters. The size, availability, reliability, low power consumption, and very high response rate are all features that have helped generate the interest in the valve. We are also examining the potential of increasing the flow rate through the valve to provide a wider range of applicability to the valve. These applications include the ability to act as a pressure and flow regulator, the ability to eliminate pressure regulators from a system due to the ability of the valve to throttle, and as a valve for cold gas thrusters where the rapid valve response allows the generation of very small impulse bits for precision control applications.
Technology Taxonomy Mapping: (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.) Actuators & Motors Cryogenic/Fluid Systems Maneuvering/Stationkeeping/Attitude Control Devices Pressure & Vacuum Systems
