Isothermal Dendritic Growth Experiment - Second United States Microgravity Payload - 2

The primary objective of the microgravity dendritic growth experiment was to measure definitively the kinetics and morphology of dendritic growth, and to account for the effects of natural convection. The experimental objective was to use a single,clearly defined experimental parameter, namely, the supercooling, to fully determine the resulting steady-state dendritic growth velocity, V, and tip radius R. Designated the IDGE, the first flight, manifested on the second United States Microgravity Payload (USMP-2) mission, was launched and operated on the STS-62 on March 4-18, 1994. This IDGE investigation met the objective of acquiring accurate dendritic growth speed and morphology data under diffusion-controlled conditions, while greatly reducing buoyancy-induced convective heat transport through the reduction of gravity. The microgravity environment broadened this range of supercooling and permitted for the first time a critical assessment of both the heat transport theory and the interfacial kinetics behavior.