The Solar Cell Test Facilities at Rockwell International are described. The facilities enable the characterization of cells in the dark and under a variety of illumination conditions. A basic automated measurements system has been built around an Analog Devices MACSYM II minicomputer. Computerized dark I-V and C-V tests allow automatic determination of barrier height, diffusion potentials, doping profiles, diode n-factors, and extrapolated reverse saturation currents. The same system is used to measure the illuminated I-V characteristics and determine ISC, VOC , F.F., and locate the maximum power point. The facility also contains a computerize spectrophotometer which performs simultaneous measurements of either absolute spectral response and reflectivity or transmissivity and reflectivity. Concentrator solar cells can be characterized at up to 200X insolation using a chopped, concentrated Schoeffel solar simulator. A unique, high concentration test facility utilizing sunlight has also been built.