We have designed a micromachined micro Coriolis flow sensor for the measurement of hydrazine (N2H4, High Purity Grade) propellant flow in micro chemical propulsion systems [1]. The sensor measures mass flow up to 6 mg/s for a single thruster or up to 24 mg/s for four thrusters. The sensor will first be used for measurement and characterization of the micro thruster system in a simulated space v...

Current research on control allocation emphasizes reconfiguration for adapting to thruster failures. However, in the application of autonomous assembly, the reconfiguration is necessitated by changing physical properties. For the scenario of an assembler tug constructing a large space structure, every docking and undocking maneuver used for the tug to move an individual payload causes a large s...

The effects of dissimilar probe design and facility backpressure on the measured ion current densities of Hall thrusters are investigated. JPL and GRC designed nude Faraday probes are used to simultaneously measure the ion current density of a 5 kW Hall thruster in the Large Vacuum Test Facility (LVTF) at the University of Michigan. The probes are located one meter from the exit plane of the Ha...

The performance metrics of a 2-kW-class thruster operated using magnesium propellant was measured and compared to the performance of the same thruster operated using xenon propellant. It was found that the magnesium thruster has thrust ranging from 34 mN at 200 V to 39 mN at 300 V with 1.7 mg/s of propellant. It was found to have 27 mN of thrust at 300 V using 1.0 mg/s of propellant. The thrust...

The plasma diagnosis technology is an essential tool to investigate the characteristics in pulsed thruster, which can understand fundamental mechanisms behind thruster. This review introduces application of diagnostic thrusters, investigates research status applied and discusses usual diagnostics methods. In contact method, Langmuir three probes thruster mainly introduced. non-contact optical e...

Ion thrusters offer the potential to enable many future interplanetary robotic missions presently under consideration by NASA. To realize the benefits offered by these low thrust devices, the sputtering mechanisms that are responsible for the degradation of thruster components over time must be well understood. Predictions of thruster life depend directly on the material removal rates from thru...

A simple model is presented for the time-averaged electron mobility within a Hall thruster. The model is predicated on the experimental evidence for isentropic electron flow and, when used in a one-dimensional simulation, captures plasma properties that are in reasonable agreement with experiment.

Direct thrust measurements by means of a balance (TB) are the golden standard for measuring and, concurrently, specific impulse in electric thrusters. To measure these properties novel class electrodeless plasma thrusters, new TB based on Variable Amplitude Hanging Pendulum with Extended Range (VAHPER) concept has been developed. The mechanical amplification mechanism an angular magnification 3...