Abstract :
During the past six years, a class of telecommunication systems designed to provide tracking, telemetry, and command functions at interplanetary, multi-million-kilometer distances has been developed and proved out on flights along heliocentric orbits and into the vicinity of the planets Venus and Mars. These developments are contributing substantially to the exploration of the solar system and, in addition, are one measure of the state of the electronic arts. If the capability continues to increase over the next several years at the same rate, we shall soon be able to transfer large quantities of information to the earth from the surface of Mars.