Cristabella Wolff, an undergraduate materials science student, drops liquid succinonitrile (SCN) into a container of cupric-oxide (CuO) nanoparticles. To the human eye, this looks like a handful of powdery soot. But soon, Wolff will have a suspension of the two materials that can be used for freeze-casting, a process that creates microscopically porous molds used in manufacturing of materials. Wolff and others studying freeze-casting at Northwestern University plan to send suspensions like this one to the International Space Station for a series of freeze-casting experiments. The scientists are using SCN for the project because, among other reasons, it is compatible with equipment on-board the ISS used for sublimation, a key part of the freeze-casting process.