In the popular mind, radar satellites have a swashbuckling image that is often associated with covertly watching over other countries and tracking their military hardware. These satellites can certainly serve that sort of function. But such spacecraft also support a range of more humdrum but vital operations. Optical satellites rely on sunlight to illuminate the ground below, working much like an ordinary camera does. Radar satellites, on the other hand, must send out pulses of radio waves and then pick up signals that bounce back. Read More
