Deep Space Network (DSN) sends signals to a spacecraft, which returns these signals to the stations on Earth. The spacecraft may also track the position of its destination against a star field.
Using precise time information from these signals, navigators calculate the spacecrafts location and velocity with respect to the Earth, and ultimately with respect to its destination. They compare the spacecraft’s current course with its desired target and calculate a course correction.
DSN stations transmit course correction commands, which the spacecraft executes.
Image Date: 2012
Credit: National Air and Space Museum, Smithsonian Institution
Origin: National Air and Space Museum, Smithsonian Institution