Erik Mueller Michael White

Introduction Problem Solution Sensing Frame Testing Q&A Sources

 Microthrusters produce <1N of thrust (mN range)  Various propulsion systems (standard, mono, ion drive)

 Thruster and forces involved are minute  Testing must be done in a vacuum  Must be rugged and durable

 Sensing is done through direct thrust measurement  Thruster assembly is suspended via a single pole  Entire device is a vacuum chamber

Thruster Mount Pendulum Mount

 Exhaust plume exerts force on a plate Induced Force Thruster

 Uses electronic principle of capacitance  Needle point fulcrums eliminate frictional losses  Double pendulum plates eliminate mechanical noise

 Series of amplifiers and filters used to measure the change in signal

 The signal processor will tie into a computer, along with the rocket ignition circuitry and vacuum monitoring sensors.  All three subsystems will be integrated into a single user-controlled program. We are considering Labview at this time.

 Currently still in the conceptual phase  Strong contender is the suspension design, via a single pole from above  Material likely to be aluminum  Easy to work with compared to steel  Strength is more than adequate for the forces involved

 Currently no concrete plans are in place  Planning to use a set of small conventional chemical thrusters (Estes model rocket engines)

Traceable calibration of the 3-axis thrust vector in the millinewton range, EB Hughes and S Oldfield, National Physical Laboratory Direct Thrust Measurement of In-FEEP Clusters, IEPC , K. Marhold and M. Tajmar, ARC Seibersdorf research GmbH Rocket Thrust Measurement For an Estes B6-2 Model Rocket Engine, Peter Hyatt, Jeremy LeFevre, Russell Dibb, Bringham Young University Thrust stand for ground tests of solid propellant microthrusters, S. Orieux and C. Rossi and D. Esteve, Review of Scientific Instruments, Volume73, Number 7, July 2002 A Ground Test Rocket Thrust Measurement System, Mary Fran Desrochers, Gary W. Olsen, M. K. Hudson, Department of Applied Science and the Graduate Institute of Technology, University of Arkansas MilliNewton Thrust Stand Calibration Using Electrostatic Fins, Allen H. Yan, Bradley C. Appel, Jacob G. Gedrimas, Purdue University