NASA's Road Maps for both Launch and In Space Propulsion call for the development of non-toxic, monopropellant reaction control systems to replace the current toxic hydrazine based systems. The Orion Multi-Purpose Crew Vehicle capsule with twelve 160 pound force (lbf) hydrazine monopropellant thrusters and the Orion Service Module with eight 100lbf NTO/MMH auxiliary propulsion thrusters are obvious insertion candidates. Additionally, the Commercial Crew and Cargo spacecraft have also demonstrated the need for 100lbf class attitude control thrusters with quantities comparable to Orion. Hydrazine replacements, including non-toxic HAN- and ADN-monopropellants, combust at higher temperatures making them incompatible with current Inconel 625 thrusters used in 100lbf engines. With an emphasis on hydrazine replacement increased performance, ease of manufacturing and cost reduction, a "green" 100lbf flight-weight thruster is being developed.
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