Electrolytic Decomposition and Ignition of AF-M315E Monopropellant

Ionic liquid monopropellants such as AF-M315E offer many advantages over monopropellant hydrazine and nitrogen tetroxide/monomethyl hydrazine (NTO/MMH) bipropellant, including increased specific impulse and density specific impulse as well as greater safety in terms of nontoxicity and insensitivity, which make them attractive for ship-based applications and can significantly decrease overall propulsion system volume, mass, and cost. In previous work, Pennsylvania State University demonstrated repeatable ignition and burn of ionic monopropellants with a novel system using flat fin electrodes for electrolytic gasification of species that can then be reacted through thermal or catalytic means. In this project, Ultramet will team with Penn State to design, fabricate, and test an AF-M315E igniter with high surface area open-cell foam electrodes to enable fast reaction times with the large propellant throughput necessary for divert and attitude control system (DACS) thrusters on missile defense kill vehicles. The high surface area electrodes will be a derivative of those developed in prior and ongoing work at Ultramet in which electrode attachment and electrical feedthrough schemes are being refined. Existing facilities and tools at Penn State will be used to evaluate the Ultramet high surface area electrodes. Propellant chemistry during electrolysis while in contact with electrodes of various materials will be characterized. The Phase II project will scale the igniter and combustion chamber to enable sizing of propulsive capability and reactivity, design and build an engine appropriate for a kill vehicle DACS, and bring the technology to TRL 6 through hot-fire testing.