View of the Wake Shield Facility, (WSF), craft on the end of Shuttle Endeavor's Canadarm, during STS-69, (9/7/95 - 9/18-95). WSF was designed as a free-flying craft to study the growth of gallium arsenide thin films by molecular beam epitaxy in space. As the WSF orbits in the rarefied atmosphere of orbit, an ultra-high vacuum is generated in the wake of the circular shield. It was hoped that this would enable in-orbit procesing of thin gallium arsenide films for use in the electronics industry.