Phase II Amount
$3,380,078
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.nbsp; 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.nbsp; 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.
