Long-range communications with Pioneer 10 at Jupiter

The longest two-way telecommunications link ever established connected Pioneer 10 with its controllers and experimenters on earth during the first Jovian encounter. This radio link, operating in the 2.1 and 2.3 gigahertz frequency bands, maintained high-quality communications over a distance of 5-1/2 astronomical units. The data collected by eleven on-board advanced scientific instruments were transmitted to the investigators, providing a new wealth of information about the largest planet of the solar system. A descriptive review is presented of the spacecraft design and the ground data system configuration with an analysis of the telecommunications downlink. Pioneer 10, aided by Jupiter's gravitational field, is the first spacecraft to leave the solar system. A plaque attached to the spacecraft represents man's first attempt to send a message to another intelligence within our galaxy.