Micro-cathode thruster for cube satellite propulsion

Summary form only given. Recently a new device namely micro-cathode arc thruster (μCAT) based on vacuum arc discharge has been developed for the spacecraft propulsion application¹. The μCAT is a micro-Newton level thrust device that employs a magnetic field and is suited for the long-time operation of micro-thruster for the nano-satellite propulsion such as Cubesats^{2, 3}. We report on experimental measurements of thruster performance characteristics and plasma properties inside and outside of thruster channel. In particular, effect of a magnetic field is studied. The cathode spot motion inside of the thruster channel and the cathode material consumption rate depend significantly the magnetic field applied. It is found that the rotation speed (B=0.3T) is about 100m/s which is 5 time more than that at B=0T. Experiment results show that the magnetic field leads a 3 times (B=0.3) increase of cathode material consumption rate (B=0T), which is the key for increasing thrust. It is also found that the magnetic field increases the total ion output by a factor of 50. The ion velocity increased by factor of two with the magnetic field applied. During the pulse thrust was measured to be about 9 mN at B=0.3T. The efficiency of μCAT has been studied based on the thruster impulse and cathode mass consumption rate measurement results. It is found that over 90% of ions have been fully accelerated with magnetic field applied.