Performance of a 50 W porous electrospray thruster in preparation for flight

The thruster head of a 50 W porous electrospray thruster called the PET-50 was characterised in order to verify its performance. Four experiments were conducted which were current voltage tests, plume angle analysis, time-of-flight mass spectrometry and direct thrust measurement. The thruster was able to emit a current of 1438 µA at a voltage of3300 V and -1394 µA at a voltage of -3400 V. The maximum plume angle was found to be 38o at a voltage of 2800 V. The time-of-flight experiments showed the thruster emitted only ions, with the plume primarily comprised of monomers and dimers. Direct thrust measurements were also conducted using a mass balance, showing the thruster could produce up to 167 µN which was in good agreement with the expected thrust based on the time-of-flight measurements, with a thrust to power at maximum power of 32.5 µN/W. Finally, the power processing unit of the thruster was verified in operation with the thruster head, showing suitably for use with a high power electrospray thruster.