Communications and Navigation Techniques of Interplanetary Travel

Radio and radar techniques will aid future space travelers in at least three major fields: navigation, communications, and collision warning. In space the basic limitation to any navigational or communications system is the achievable range. Presentday techniques are capable of providing point-to-point beamed coverage of the entire solar system, but they are inadequate for omnidirectional coverage even to the nearest planet. Sufficient advances in the state of the art by 1975 are foreseen to insure omnidirectional coverage within the orbit of Jupiter. Communications to the nearest stars appear impossible even with anticipated 1975 techniques, and radar warning systems against meteors appear impractical.