Abstract
A practical, high-precision method for measuring the mass of an astronaut under microgravity conditions is proposed. Using an instrument called the “Space Scale”, the velocities of a target object and a reference mass are measured with high accuracy by optical interferometry. The two are connected by a linear ball bearing and have separate linear-motion states, with some acceleration due to friction in the linear ball bearing. For this paper, a ground instrument was developed in which linear motion of the whole mechanical system is achieved with negligible external force by means of a pneumatic linear bearing. The effect of linear ball bearing friction that involves the target object and the reference mass is theoretically negligible, as we proved experimentally in this study. We conclude that an operational model for in-orbit use, which takes advantage of an optical interferometer, would be extremely compact and accurate.
