Stretching the Operational Envelope of the PPS ® X000 Plasma Thruster

The PPSX000 technological demonstrator thruster has been characterized by testing up to a power level of 6.5 kW and a discharge voltage of 1 kV, corresponding to a maximum total specific impulse of 3240 s. A peak thrust efficiency of 58% was obtained at 5 kW of discharge power near 650 V, with a corresponding total specific impulse of 2600 s. The maximum demonstrated thrust was 335 mN at 6 kW / 300 V. The test data indicate a rather large domain of stable thruster operation, in particular between 550 V and 850 V of discharge voltage. The low-voltage discharge characteristics emphasise the role of the discharge oscillations on electron mobility in the discharge channel, and the effect of adjusting magnetic induction.