Microgravity processing

Frazier, D. Paley, M. Penn, B. Abdeldayem H. Smith, D. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials. In MSFC Center Director s Discretionary Fund Final Report, Project No.95-26, NASA Technical Memorandum 108533,1997. 

Space shuttle -microgravity experiments [SPACE PROCESSING] (Vol 22) -use of ablative materials [ABLATIVE MATERIALS] (Vol 1) -use of high temperature alloys [HIGH TEMPERATURE ALLOYS] (Vol 13)... 

This microgravily environment gives researchers a unique opportunity to study the fundamental states of matter, solids, liquids, and gases, and the forces that affect them. In microgravity, researchers can isolate and study the influence of gravity on physical processes, as well as phenomena that are normally masked by gravity and thus difficult, if not impossible, to study on Earth. 

Because cniivecliou and diffusion occur simultaneously in an earth-based process, corresponding studies in a micrograv ity environment can help identify I he elTecl.v of these two phenomena on a given process such as cry sul grow ih. 

S. J. Sansonetti, Consultant, Reynolds Metals Company, Richmond. V/V h 1 tp //www.aIcoa.com/, Aluminum and Cryolite Robert P. Sanlandrea, Ph.D Lis Alamos National Ltbonuory. Lis Alamos. NM. hup //wwv. larl.gov/worldview/. Microgravity and Materials Processing... 

Density gradients are established at several stages in the crystallization process (Fig. 5). As molecules attach to the growing crystal surface, the solution near the crystal is depleted of solute and becomes less dense than the bulk solution. Under the influence of gravity, such density differences result in convection currents. However, in microgravity, solutions with different densities are not subject to convection, so that solutions mix with less turbulence (Littke and John, 1984) and equilibration between solutions is much slower (DeLucas et al., 1986). 

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