Technology is available for satellite-to-satellite communication via visible-light laser; satellite-to-ground transmission will be tested in the early 1980. A solar-radiation-powered Nd:YAG laser operating at 532 nm and generating 400 mW will transmit 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> bits of data (≈ Encyclopaedia Britannica) per second.