RAMOS, the Russian American Observational Satellite program, is a cooperative space-based research and development program between the Russian Federation and the United States. The planned system configuration is a constellation of two satellites orbiting in approximately the same plane at an altitude of about 500 km, separated from one another by a variable distance centering on about 500 km. These satellites are equipped with passive electro-optical sensors, both US- and Russian-built, that operate over a range from infrared (IR) to ultraviolet (UV) and are designed for near-simultaneous stereo imaging capability. The sensor suite will include visible, IR and UV imaging radiometers, an IR spectrometer, and a short-wave infrared (SWIR) polarimeter. The projected launch date is 2008 with a planned minimum on-orbit lifetime of two years, and a five-year lifetime possible. This paper summarizes the program objectives, anticipated measurements and expected data, and presents the basic system design, expected performance characteristics, and the capabilities of each of the sensors.