Arcjet Operating on MMH and UDMH

Period of Performance: 08/28/2000 - 08/28/2002


Phase 2 SBIR

Recipient Firm

Busek Co., Inc.
11 Tech Circle
Natick, MA 01760
Principal Investigator


Most spacecraft use bipropellants, monomethylhydrazine (MMH) and usymmetrical dimethylhydrazine (UDMH), for their chemical on-board propulsion. Busek proposes to use the same propellants in a novel arcjet to capitalize on the existing on-board propellant storage and flow control systems while significantly improving the mission average Isp. This leads to a greater payload, or reduced S/C mass with concomitant decrease in launch costs. In Phase I, Busek demonstrated the feasibility of the bipropellant arcjet using simulated MMH. In Phase II, Busek, TRW and ValveTech will continue the arcjet development in a two part (Segments A and B) program, that culminates in demonstrating an EDM-like bipropellant arcjet at TRW using the actual propellants. Both Segments A and B are significantly cost-shared by all team members with the greatest portion offered by TRW in Segment B, where the commercial-to-government dollars are about 5:1. In Phase III, the same team will commercialize the bipropellant arcjet and offering heretofore unavailable option for on-board S/C propulsion. 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.