Tracking and Data Relay Satellite System

Overview
The Tracking and Data Relay Satellite System "consists of several satellites in geostationary orbits around the Earth."

"The Hubble Space Telescope and the International Space Station send data to ground station antennae via the Tracking and Data Relay Satellite System to ground stations in New Mexico and Guam. Data received from spacecraft are stored at antenna facilities until they are distributed to the appropriate locations through ground communications such as IONet. When data are sent to spacecraft these pathways are reversed."