High Total Impulse BET-MAX System for Small-Sat Deorbiting

An updated beam target will be designed, fabricated, and utilized for all electrospray testing tests. The function of this target will be to minimize SEE and positive/neutral species back-streaming to the thruster, thus eliminating facility effects from life testing. A modified lab model thruster will be fabricated and used to initiate rapid testing within 3 months of program start. Results will be use for feed system model improvements, as well as initial validation of the improved beam target and prolonged thruster operation at 2,000s. Feed system models will focus on incorporation of additional physical phenomena to improve performance predictions, particularly at low reservoir saturations. Lessons learned from early testing will be incorporated into an EM thruster design that will be environmentally tested (vibe, shock, and TVAC) and subjected to life testing. An analytical model will be developed to predict CNT cathode performance when multiples are operated from a common supply. A singular 4X cathode assembly will be designed, fabricated, and life tested to assess for current sharing and performance at high current (4mA) over thousands of hours. New cathode deflector materials for high SEE emission will be tested and included in the new baseline design if they demonstrate higher cathode current effective yield. A protoflight system will be fabricated and subjected to protoflight qualification per NASA GEVS. This system will consist of four high-Isp BET-300-P thrusters with extended reservoirs, a quad-cathode assembly, powered by a common PPU. Upon protoflight testing, the system will be delivered for potential future flight demonstration. In support of future missions beyond LEO, the present rad-hard/COTS hybrid electronics design will be updated to a fully rad-hard BoM. Updated schematics and board area studies will be completed, along with a more detailed radiation assessment of the present hybrid design.
Benefits: NASA APPLICATIONS NASA recognizes the importance of electrospray propulsion to attitude control, formation flight and positioning of smallsats. Applications benefiting from precision pointing include deep-space missions, exoplanet astronomical missions, planetary observations, and laser communications. Improved body pointing and position control would enable previously unobtainable stability and resolution; permitting both lower cost/complexity realization and enabling new objectives. Particularly though virtually eliminating reaction wheel induced vibrations. NON-NASA APPLICATIONS High performance compact propulsion systems are an enabling technology for commercial small-sat missions. Applications include optical communication alignment for high bandwidth or precision pointing during EO missions. De-orbiting applications are particularly relevant to new LEO EO and telecommunication initiatives, as well as smallsat internet-of-things global communication constellations.