A microplasma thruster has been developed of electrothermal type using azimuthally symmetric microwave-excited microplasmas. The microplasma source was ~2 mm in diameter and ~10 mm long, being operated at around atmospheric pressures; the micronozzle was a converging-diverging type, having a throat ~0.2 mm in diameter and ~1 mm long. Numerical and experimental results with Ar as a working gas demonstrated that this miniature electrothermal thruster gives a thrust of >1 mN, a specific impulse of ~100 s, and a thrust efficiency of ~10 % at a microwave power of <10 W, making it applicable to attitude-control and station-keeping maneuver for a microspacecraft of <10 kg.
Microplasma thruster for ultra-small satellites: Plasma chemical and aerodynamical aspects
