Free motion of an unsupported tank that is partially filled with liquid

The motion of a partially filled tank is studied for its relevance to the control of maneuvering space vehicles with liquid stores. For numerical simulations, a number of computer programs were developed. An experimental program with investigations on parabolic flight in suborbital and orbital trajectories was defined and is in preparation. The present immediate objective is the synthesis of the so called Wet Satellite Model (WSM) experiment which includes the development of a diagnostic instrument ('ballistometer') and the launch of a test article in a seven minute parabola by sounding rocket. A breadboard model was flown on parabolic flight. The tests of the breadboard have as their primary purpose the assessment of the performance of the instrumentation to determine the motion. This instrument will consist of nine linear microaccelerometers that are arranged about the body. The equations that govern the behavior of the unsupported tank are given and discussed.