Satellite Systems

Space Ground Transmitter Receiver Controller

The Space-to-Ground Subsystem is a key communications structure for the International Space Station. Our Transmitter/Receiver/Controller and Space-to-Ground Antenna are mounted on the outside of the station and provide high-rate data communication with the ground.

Bridging the divide

The system can handle standard and high definition video and transmit pre-recorded messages or live, two-way conference calls. This is used to communicate with the Mission Control Center in Houston and transmit scientific data. More importantly, it lets crew members contact their families back here on Earth.


  • 600 Mbps – Rate of data transmission to the ground
  • 0.5 – Degree of accuracy at which the system must target the Relay Satellite to transmit data
  • 12-18GHz – Spectrum for the Ku-band satellite frequency used by the subsystem
  • 6 months – Average length of time ISS crew are away from family and friends