The Fluid Processing Apparatus: from flight hardware to electron micrographs

Sweet clover seeds were grown in the Fluid Processing Apparatus (FPA) flown on STS-54 (January 1993) and STS-60 (February 1994). After germination and seedling growth for 40 hours, seedlings were fixed in space. Electron microscopy was used to examine the seedling ultrastructure to verify that fixation occurred and preserved the samples. Micrographs revealed well-preserved cell structure and the presence of calcium precipitates indicating complete fixation. FPA is a useful piece of hardware for preservation/fixation during spaceflight.