A 1 kW-class arcjet thruster was fired in a vacuum chamber at a pressure of 18 Pa.A gas mixture of H_2 : N_2 = 2.8 : 1.5 in volume at a total flow rate of 4.3 slm was used as thepropellant with an input power fixed at 860 W. The time-dependent thrust, nozzle temperatureand inlet pressure of the propellant were measured simultaneously. Results showed that with theincrease in nozzle temperature the thrust decreased and various losses increased. The physicalmechanisms involved in these effects are discussed.
