(PPG)(10) crystallization experiments onboard the ISS using the Advanced Protein Crystallization Facility have shown parallel and coherent crystal motions. The residual acceleration profiles and the History of the ISS Increment 3 mission allow a quantitative interpretation of these motions. Two events determine the observed crystal motions: the undocking of the Space Shuttle and a change in the ISS attitude required for power generation. No correlation between these motions and the crystal quality is apparent.