Telescopes at the Goldstone observatory in California, USA. The radio telescopes form part of NASA's Deep Space Network (DSN) which supports interplanetary spacecraft missions. DSN consists of three facilities spaced equidistant around the world. The placement of the sites permits constant communication with spacecraft as the Earth rotates. The antennas of the DSN provide the connection for commanding spacecraft and receive their data. The DSN also provides radar and radio astronomy observations of the solar system and universe.