THE DEVELOPMENT AND QUALIFICATION OF A 4.5 KW HALL THRUSTER PROPULSION SYSTEM
This paper provides an updated status of the 4.5 kW Hall Thruster Propulsion Subsystem development and qualification program at Aerojet’s Redmond operation (formerly General Dynamics Space Propulsion System) and Lockheed Martin. This subsystem is being developed to support geosynchronous satellite applications for both commercial and military applications. This paper describes the mission application, performance, program plan and current status of the development program. The overall system, including the Power Processor Unit, the Xenon Flowrate Controller, the Hall Thruster and Cathode and the Xenon Feed System is also described. The system currently under development is planned to be used for both orbit insertion from an initial geosynchronous transfer orbit and on-orbit stationkeeping and repositioning maneuvers. The HTPS takes advantage of the dual-mode capabilities and wide operating power range of the Aerojet BPT-4000 Hall thruster to maximize efficiency for each mission phase.
Development of hall thruster propulsion system for STSAT-3 application
Abstract Science and technology satellite-3 (STSAT-3) is being developed and is scheduled for launch in 2011. One of the primary objectives of its mission is to verify the performance of a hall thruster propulsion system (HPS) that uses xenon gas. According to its major functions, the HPS can be divided into several sub-modules. This paper presents the development and qualification of the hall effect thruster propulsion subsystem that includes a xenon feed system (XFS). The xenon feed system regulates the pressure down from the xenon propellant tank and supplies the xenon flows to the anode and cathode. The technology and xenon feed system developed for the STSAT-3 spacecraft will also be applicable to a variety of future electronic propulsion systems and micro-satellites. Details related to the overall development and performance results of the HPS are presented in this paper.
HYPERGOLIC REACTION MECHANISMS OF CATALYTICALLY PROMOTED FUELS WITH ROCKET GRADE HYDROGEN PEROXIDE
Abstract The coupling of the physical and chemical processes controlling the ignition delays (τ ign ) of hypergolic propellants complicates the direct analysis of the transient ignition processes. The transport properties of both the propellants and the ambient gas, and the heat of vaporization and reaction affect τ ign and must be considered experimentally. Furthermore, since hypergolic ignition occurs, by definition, on contact, the mechanics of initial contact and subsequent mixing can affect τ ign and must also be considered. Experimental results from a study of the hypergolic ignition of a catalytically promoted fuel with rocket grade hydrogen peroxide (RGHP) are presented. Statistical analysis of the experimental data was conducted to evaluate the relative effects of RGHP concentration, initial ambient pressure, and the ambient gas on τ ign . At RGHP concentrations of less than 92% in water, stable ignition was difficult to achieve. At sufficiently high Lewis number, an oscillatory ignition process is observed. A phenomenological model comprising mixing, RGHP decomposition, fuel heating and vaporization, and auto-ignition is presented and compared to the experimental results.