This project will further development of a thruster capable of both chemical monopropellant and electrospray propulsion using a single "green" ionic liquid propellant. the thruster concept consists of an integrated microtube/electrospray thruster that shares all propulsion system hardware between electric and chemical thruster modes, i.e. one propellant, one propellant tank, one feed system, and one thruster. Thus, the thruster is not significantly more massive than a standalone state-of-the-art chemical or electric thruster, but capable of either thrust mode and selectable as mission needs arise. This has several benefits, including the optimization of trajectories using both chemical and electric thrust manuevers as well as a significantly increased mission design space for a single propulsion unit. The propulsion system is capable of both high impulse per unit volume and high thrust per unit volume as the total impulse per unit volume is 1500 N-s/U in the chemical thrust mode and 2750 N-s/U in the electric thrust mode, where either type of manuever could be selected on-the-fly. Operation and high performance in both modes has previously been demonstrated at the single emitter level. The specific objectives for this study are to design and build a cubesat sized multi-emitter thruster and test in both chemical and electrospray modes of operation. Two thrusters will be built and separate chemical and electric thrusters tested in parallel. Then, back-to-back operation of a single thruster will be demonstrated and indirect and direct performance measurements will be acquired. Additionally, the development of the multi-mode monopropellant will be furthered through material compatibility tests and hazard classification. Finally, system level items including PPU and and feed system components will be researched and selected and/or designed.
Potential NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) Multi-mode propulsion fulfills NASA technology needs as outlined in the In-Space Propulsion Technology Roadmap, monopropellant microthrusters and electrospray thrusters, as well as fulfilling needs highlighted by the National Research Council, specifically the need for both chemical and non-chemical propulsion that fulfills the needs for high mobility micro-satellites and extremely fine pointing and positioning for certain astrophysics missions. Research has shown the benefits of multi-mode micropropulsion for NASA missions, including, more efficient small satellite formation flight, optimized attitude control, enhanced transfer rate and useful mass for Jovian missions, more favorable conditions for lunar impact, launch mass savings, and payload mass advantage to GEO. Additionally, the flexibility of the multi-mode propulsion platform allows for a common unit to be used for many different types of missions, eventually reducing both risk and development time for many types of science payload missions.
Potential NON-NASA Commercial Applications:
: (Limit 1500 characters, approximately 150 words) Multi-mode micropropulsion has potential to meet Air Force needs for fractionated, composable, survivable, autonomous systems, i.e., satellites that can be assembled, tested, and launched within days of operational requirement. Specifically, the large mission design space resulting from ability to select and complete chemical or electric maneuvers at will significantly enhances the capabilities of these 'plug-and-play' satellites. It has potential to impact the exploding small/CubeSat market, an estimated market value of $7.4B, with a predicted 360% increase in launches over the next 5 yrs, and future plans for competing space-based internet constellations. The large mission design space enabled by multi-mode propulsion could be beneficial to this market in that a single, off-the-shelf system is capable of many different types of missions. An entirely new propulsion system would not have to be developed for each mission individually, reducing costs associated with development, testing, and risk. Additionally, the multi-mode capability has been shown to drastically increase the mission capabilities of swarms or constellations of small satellites.
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.) Fuels/Propellants Maneuvering/Stationkeeping/Attitude Control Devices Spacecraft Main Engine
