Targeted to lift off Aug. 24, the NASA Space Shuttle Discovery will take six materials science experiments to the International Space Station’s (ISS) U.S. Laboratory Destiny for low-gravity experiments to be conducted by astronauts aboard. The NASA expedition is part of a collaborative research program with the European Space Agency. The U.S. team, consisting of Professors David Poirier and Robert Erdmann (University of Arizona), Professor Surendra Tewari (Cleveland State University), and Dr. Frank Szofran (NASA Marshall Space Flight Center), is studying variances in the crystallization of metals in space and on Earth. The aim is to understand to what extent convection (the transfer of heat by movement of fluid) is responsible for creating defects in castings as well as what happens to these defects when solidification occurs in space, where convection is “significantly reduced.” The experiments will examine how single-crystal dendritic castings—critical components in high-temperature gas-turbine engines—solidify differently in space and how growth speed changes influence their grain structure. Knowledge gleaned could help the casting industry improve processing behavior and eliminate defects.