Arcjet Operating on Propellant Grade Hydrazine, MMH and UDMH

The Lockheed Martin 7000 series and other spacecraft use ultra pure hydrazine for both their chemical apogee motor and the orbit/attitude controlling arcjets. Busek proposes to extend this highly synergistic and beneficial "dual-mode" propulsion to other widely used fuels including propellant grade hydrazine (PGH), monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). This will be achieved by applying our methane arcjet experience to develop a new 2 kW arcjet capable of efficient, high Isp operation on any of the above listed fuels. In Phase I of the program an existing radiation cooled methane arcjet will be used to determine its operating characteristics on simulated PGH, MMH and UDMH fuels. Thrust will be measured as a function of mass flow and power input. This data and concurrent numerical modeling using our existing will be used to design a new 2 kW arc jet. In Phase II the new 2 kW arcjet will be constructed and thoroughly characterized using first the simulated and then the actual liquid propellant(s). Development of a flight version will be initiated and the arcjet will be marketed to satellite manufacturers. All arcjets, regardless of their propellant, can benefit nearly all geostationary spacecraft. The benefit is maximized when they use the same fuel as the chemical apogee motor(s), sharing propellant storage and most propellant management systems. The resulting mass and complexity reduction is expected to yield a five figure or higher cost reduction per spacecraft.