ISS Fluid Slosh

ISS SPHERES Fluid Slosh main objective is to gather long duration, low gravity slosh data in order to calibrate Computation Fluid Dynamics (CFD) models of low gravity coupled fluid-vehicle behavior.

The project is set to be completed in two main phases. First is a proof of concept concerning the utilization of SPHERES on the International Space Station.  The second phase involves the design, manufacture, launching, and testing of externally mounted fluid tanks to the SPHERES assembly which are sized and instrumented to provide high quality representative data on scaled upper stage tank configurations.

The experimental data is to be produced using video and inertial measurements of high mass fraction, low gravity slosh events taken across a sizeable test suite. The results provided should be a valuable resource in providing the first-ever long-term fluid slosh data at micro-gravity levels that can be used for benchmarking and anchoring of mathematical fluid slosh models of any form.

STMD Fluid Slosh experiment begins on the International Space Station

Principal Technologist: Ryan Stephan (

Project Manager: Paul Schallhorn (