The Aerospace Corporation has decades of experience doing radiometric characterization testing of imaging arrays, known as focal plane arrays (FPAs), built for space applications, both scanning and staring types. The purpose of the Sensor Test, Evaluation, and Prototyping (STEP) Lab is to provide mission operations support from the early development phases of an electro-optical system procurement, build, integration, and test to on-orbit performance analysis, calibration, and anomaly resolution. The STEP Lab plays an integral role at every stage of a program lifecycle.