The Solid Expellant Plasma Source/Contactor (SOLEX-PSC) will provide an efficient, robust and low-mass capability for making electrical contact with the environmental plasma of an electrodynamic tether system, or providing an efficient source of plasma for plasma sails such as M2P2. The device will operate directly off of the tether-generated high-voltage (requiring no conditioned power or control electronics) and its current capacity can range from a few milli-amps to several amps. Moreover, the SOLEX-PSC will eliminate the need for high-pressure gas containers, pressure regulators, plumbing and valves required by present state-of-the-art Hollow Cathode devices. By nature of its design, the SOLEX-PSC should not be sensitive to contamination and should have essentially unlimited restart capability; both are issues with state-of-the-art contactors. Moreover, the simplicity of the design concept suggests that flight devices will be relatively inexpensive. Phase I will investigate various expellant materials and electrode geometries, determine the effects of the space plasma environment on operations, and carry out proof-of-concept testing on a bread-board model. The purpose of Phase II would be to design and develop a flight-ready system and to carry out life testing. POTENTIAL COMMERCIAL APPLICATIONS The simplicity, robustness and efficiency of the SOLEX-PSC should make it an attractive alternative to present devices in any application where a plasma is required. This includes such in-space applications as electrodynamic tethers, plasma sails such as M2P2 and spacecraft charge neutralization, but also could include ground-based commercial applications such as plasma sputtering or coating. The SOLEX-PSC is particularly needed in the application of electrodynamic tether devices to end-of-life deorbit of satellites where system mass, simplicity and robustness are critical concerns. As space debris becomes a growing concern to NASA and the DOD, this application will become increasingly important.
