Space communications

Preliminary design parameters for space communications can be estimated by standard application of the radiation range equation and of communication-theoretic equations relating channel capacity to bandwidth and signal-to-noise ratio. An example is given for a hypothetical situation involving communication between a space vehicle and a receiver located on the earth's surface, for various communication ranges. Preliminary estimates of this type also serve to indicate areas of research and development which will be of importance in space communications. Some of the areas briefly mentioned are: components (vehicle and surface antennas, sensitive receivers, highly reliable circuit components, and electrical power sources); signal storage, encoding, and processing techniques; tracking and acquisition techniques; and studies of the physical environment (extraterrestrial noise, component environment, and electromagnetic propagation environment in space).