Methods for measuring mass of general objects under microgravity conditions

The methods, which have been proposed by the author and under development for quick and accurate mass measurements under microgravity conditions using the law of conservation of momentum, are reviewed. In the experiment, the velocities of two different uniform motion states of the object and the impulse, i.e. the time integration of the impact force, between them are measured, and then the mass of the object is determined. The velocity is measured highly accurately using an optical interferometer. In this paper, the mass of a non-rigid object is determined with the relative standard uncertainty of approximately 0.5 % by means of estimating the velocity of the gravity center of the object. Some points to be considered for measuring the mass of the general objects under microgravity conditions are discussed.