Skynet Satellite
United States Antarctic Program United States Antarctic Program Logo National Science Foundation Logo
Read the latest information from NSF on coronavirus (COVID-19)
An artist's depiction of the Skynet-4 satellite series
Photo Credit: Airbus Defense and Space
An artist's depiction of the Skynet-4 satellite series.

The Skynet Satellite Communications System is the United Kingdom's (UK) Ministry of Defense (MoD) military satellite communications system. The Skynet program was privatized via a Public Finance Initiative (PFI) in 2003, and extends through August 2022. The PFI outsourced operations of the satellite constellation and ground infrastructure to what is now Airbus Defence and Space with the space and ground assets reverting to British government ownership at the end of the contract. Airbus has channel partner agreements to resell Skynet services to NATO and Allied countries - such as the U.S. The Skynet-4 series satellites were constructed by British Aerospace prior to the PFI with Skynet-4C as the sole surviving satellite of the first tranche of three satellites.

The 9 Meter Radome at South Pole Station houses the Skynet terminal
Photo Credit: Chet Waggoner
The 9 Meter Radome at South Pole Station houses the Skynet terminal.

The Skynet-4 series of satellites were designed to operate without active positioning of the satellite north and south of the equator - referred to as north-south station keeping. This results in a gradual increase of the satellites orbit inclination with respect to the equator; therefore, the Skynet-4C satellite drifted into the highly inclined geosynchronous orbit that provides a limited direct visibility with South Pole Station.

The South Pole terminal uses a 2.4 meter X-band antenna system designed by Global Satcom Technology, Inc., commonly referred to as a VSAT (Very Small Aperture Terminal). It is currently used for the South Pole DSCS terminal as well, providing redundancy for spare parts and operational management.

Skynet-4C is visible to South Pole Station for approximately six hours each day, and provides a symmetric bi-directional link of 1.544 megabytes per second (Mbps) for the station's internet connectivity, phone, and video services. Gateway teleport services are provided by Airbus at its facility located at the former Royal Air Station in Oakhanger, East Hampshire, England. Airbus channel partner Intelsat General provides trans-Atlantic backhaul communications to the USAP wide area network hub in Denver via its IntelsatOne terrestrial fiber optic network.

Satellite Link Information
Satellite Skynet-4C
Manufacturer Airbus
Design Life 7 years
International Designator 1990-079A
Launch Date August 30, 1990
Operating Frequency Range Military X-Band
Daily Contact Window 5.8 hours (increasing annually)
Daily Window Opening Reference the Weekly Satellite Service Schedule
Uplink (outbound) 1.5 Mbps
Downlink (inbound) 1.5 Mbps
South Pole Terminal 2.4 m aperture VSAT
Oakhanger, England, Terminal 11.6 m