Design and Fabrication of Electrospray Thruster Packaging and Fuel Tank
Louis Perna, Paulo Lozano (Associate Professor)
As demand for small satellite missions grows, the need for lightweight, high-thrust, modular propulsion systems becomes more and more apparent. Ion electrospray propulsion can fulfill the role of miniaturized space propulsion without the unwelcome inefficiencies of mass or power which other technologies have stumbled over. While electrospray thruster technology is still in development, and the desired theoretical performance levels remain on the horizon, the SPL has produced a first-generation Ion Electrospray Propulsion System (iEPS) and its successor (iEPS2) is currently in the fabrication phase. By design, each iEPS2 thruster can be assembled to take advantage of the most recent advances in research. This flexibility allows the iEPS2 to act not only as a flight-worthy, modular thruster, but also as a test bed for future work.
Objective of the Research
iEPS2 has been designed with the performance faults of its predecessor in mind---mainly electrical shorting and lack of disassembly. Various features of the thruster package are included solely for the purpose of mitigating liquid transport from the emission area of the device to the opposing electrode. The desire is for near, if not complete, elimination of liquid contamination and shorting between emitter and extractor as a means for improving thruster lifetime. Additionally, the previous design required permanent assembly of the devices. Therefore, access to the emitter after testing required device destruction, and extractors could not be swapped. In the new design, the extraction layer is (1) removable/replaceable, (2) allows for mounting of second grid, and (3) complies with a packaging alignment standard for compatibility with future designs.
Development of an Ionic Liquid Fuel Tank
Fuel tank development for space-worthy electrospray propulsion systems has not been adequately addressed in the field. The goal of the fuel tank design and research here is to demonstrate near-complete transport of liquid fuel to the emission surface without the use of active (mechanical) means. Several architectures are under consideration including a traditional solid tank, a flexible membrane tank, and a remote tank with capillary feed. Each design has benefits which are exploited based on the size and configuration of the thrusters they serve.