Two-Phase Ammonia Pump for Mono-Propellant Warm Gas Pressurization

An integrated warm gas pressurization of the main and ACS propulsion system offers simpler, more efficient propellant management than existing designs.  The most operationally versatile system is based on a unique pump that forces liquid through a gasifier thus creating both the pressurant gas and warm gas for ACS thrusters.  All components of such a system are COTS with the exception of the pump which will be the Phase 1 focus.   The proposed pump uses no motors or mechanisms and has only one slowly moving part.  In addition to mass and volume reduction, the system offers benefits such as launching the entire propulsion system unpressurized and a constant tank pressure operation which improves thruster performance.  Furthermore the warm gas can be used in place of cold gas for attitude control thrusters, providing increased specific impulse.   In Phase I we will build and demonstrate the pump and model the dynamics of the entire propellant storage and management system. In Phase II we will produce and characterize the entire system, including the gas generator and investigate its dynamics.  The goals will be more than a factor of two in pressurization system mass and a greater than 10% increase in thruster performance.    BENEFITS: Successful demonstration of the proposed technique will enable use of warm gas pressurization on any spacecraft using mono-propellants, significantly improving propulsion system performance while reducing the system mass and volume.  Warm gas pressurization could also possibly be used for bi-propellant systems.   A majority of spacecraft have one or the other, so that significant impact is expected.