Flight Demonstration of Electrostatic Thruster under Micro-Gravity

Based on a new concept, a low power electrostatic thruster is being developed for its application to 50 kg class satellite, which is named “Microwave Engine”. The proto-model (PM) of the microwave engine was manufactured and the qualification test (QT) was conducted. The estimated performances are 1250 seconds in specific impulse, 0.36mN in thrust and 10% in thrust efficiency when it is operated at 26.6W. To evaluate the feasibility of its accelerating mechanism, the flight demonstration of a plasma thruster is implemented under microgravity. The demonstrated thruster has an aperture of 19 mm in diameter. The same accelerating mechanism as Microwave Engine is applied to the plasma thruster although there is a difference in the mechanism of generating plasma. The flight demonstrator utilizes the glow discharge while the microwave discharge is applied to Microwave Engine. In this study, the thrust is estimated based on the flight path of the plasma thruster under microgravity, the swing of its pendulum under 1G and the beam theory of its copper wires. These corresponding thrusts are 0.36 mN, 0.20 mN and 0.11 mN, respectively. In addition, a series of its flight images is shown in this paper. As a result, the reasonable flight performance validates the accelerating mechanism of Microwave Engine

Continuous Operation of Micro Plasma Thruster “Microwave Engine”

A low-power, microwave-discharge type electrostatic thruster named “microwave engine” has been developed for applications to 50 kg-class satellites at Advanced Technology Institute Ltd. (ATI) in Hokkaido, Japan. A prototype of the engine was manufactured, and its performance and random vibration tests have been reported in previous papers. An endurance test followed, and showed no failure in the engine after 400 hours of operation