Micropump for MON-25/MMH Propulsion and Attitude Control

Flight Works is proposing to expand its work in micro-gear-pumps for hypergolic and "green" propellants and team with Aerojet-Rocketdyne in order to develop and demonstrate a micropump for MON-25 and mono methyl hydrazine (MMH) bipropellant thrusters. MON-25, with 25% of nitric oxide (NO) and 75% nitrogen tetroxide (NTO, N2O4), allows lowering the oxidizer freezing point to -55 C, which is a close match to that of the fuel, MMH (which is around -51 C). While toxic, this propellant combination is hypergolic and allows operations over a wide range of temperatures, particularly in extremely cold environments as those envisioned for many future missions. The introduction of a micropump in the propulsion system provides many benefits, including the elimination of the pressurization systems; lighter, cheaper, and conformal tanks; improved system packaging; removal of propellant cross-contamination in the pressurization system; and long term storage for extended duration missions (since the loss of helium is no longer a concern). Under a Phase I SBIR, Flight Works Inc. is prepared to develop and characterize a micropump suitable for both MMH and MON-25, initially sized for 22-30 N (5-7 lbf) class thrusters with approximately 2.5 MPa (365 psi) inlet pressure, with the goal of demonstrating the technology with pump-fed MMH/MON-25 hot fire tests by the end of Phase II.