Fermentation processes are highly dependent upon physical and chemical environmental parameters, many of which are influ-enced by gravity. Extending biotechnology into the realm of space flight provides researchers with an opportunity to investigate the role that gravity plays in natural growth processes. Physical factors governing cell sedimentation, nutrient mixing and byprod-uct dispersion are altered in the absence of the constant sedimenting force of gravity. In addition, space flight has also been shown to give rise to a wide variety of indirect consequences associated with the physiology of the organisms themselves.