Since 1985 the National Aeronautics and Space Administration (NASA) has supported fundamental studies on the various factors that affect protein crystal growth processes. More than thirty principal investigators from universities throughout the United States have investigated questions such as why crystals stop growing, what factors cause defect formations in growing crystals, and what influence parameters such as protein purity, temperature, pH (a solution's degree of acid or base properties), protein concentration, and fluid flows exert around growing crystals.

The majority of these studies were conducted in Earth-based laboratories, with a limited number of experiments performed on U.S. space shuttle flights. The purpose of the space experiments is to determine the effect that a microgravity environment has on the ultimate size and quality of protein crystals. This research was propelled by the need to improve success rates in producing high-quality crystals to be used for X-ray crystallography...