Design of a liquid sloshing experiment to operate in the International Space Station

This paper provides a description of the design details of the SPHERES Slosh Experiment (SSE), aboard the International Space Station. The description spans various design elements including the mechanical, electrical and software design of the SSE and create a background for developers creating their own payload. Learned lessons from 3-D printing applied to ISS experiments is also shown, based on the experience gathered with the SSE. This document provides a starting point read for anyone who desires to design and build an ISS experiment, especially if using the SPHERES platform. The SSE aboard the ISS is designed to acquire long-duration liquid microgravity data used by engineers on earth to validate and improve the CFD prediction models, improving the design of the next generation of space vehicles as well as the safety of the current missions. The experiment makes use of two Synchronized Position Hold, Engage, Reorient Experimental Satellites (SPHERES), already on the ISS, connected by a frame. In the center of the frame there is a plastic, pill shaped tank that is partially filled with green-colored water. A pair of high resolution cameras records the movement of the liquid inside the tank as the experiment maneuvers within the ISS test volume. Inertial measurement units record the accelerations of the tank, making the combination of stereo imaging and inertial data the inputs for CFD model validation.