School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Johannesburg, 2000 Gauteng, South Africa; South African National Space Agency (SANSA), Space Science Directorate, Hermanus, 7200 Western Cape, South Africa
Lun, J., School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Johannesburg, 2000 Gauteng, South Africa, South African National Space Agency (SANSA), Space Science Directorate, Hermanus, 7200 Western Cape, South Africa; Law, C., School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Johannesburg, 2000 Gauteng, South Africa
A robust stand for directly measuring pulsed thrust from micro-thrusters is presented. The method of electrostatic discs for in situ calibration was improved upon and simplified to allow convenient and accurate thrust measurement. The novel use of frictionless liquid gallium metal power interfaces for μN-level force measurement stands was also demonstrated. A series of detailed verification tests were performed to characterize the thrust stand's overall operating range and accuracy. The stand can test single and multiple thrusters with a total mass of up to 10 kg and was found to be capable of resolving impulse bits between 0.27-600 μNs with 2-4% error in the optimal deflection range. Demonstration of the thrust stand's capability and resilience to electromagnetic interference was accomplished by performing lifetime thrust tests on low-power Vacuum-Arc Thrusters operating with three different cathode fuels. © 2014 IOP Publishing Ltd.