A high-resolution thrust stand for ground tests of low-thrust space propulsion devices

A new type of thrust stand for accurately measuring a low-level (10 mN to 1 N) thrust produced by a space propulsion device in its ground tests has been developed. Vacuum bellows are utilized both as a feedthrough tool from electrical power, propellant, and coolant supplies to a thruster installed in a vacuum chamber, and as an elastic support. In order to improve thrust resolution, friction force on radial bearings at a fulcrum is minimized by eliminating bearing radial forces. 0.5 mN thrust resolution was experimentally obtained. Utilizing thrust stand vibration characteristics measured in advance, a computer-processed, quick thrust reading system has been established.