Skynet (satellite)

Skynet is a family of military communications satellites, now operated by Babcock International on behalf of the United Kingdom's Ministry of Defence (MOD). They provide strategic and tactical communication services to the branches of the British Armed Forces, the British intelligence agencies, some UK government departments and agencies, and to allied governments. Since 2015 when Skynet coverage was extended eastward, and in conjunction with an Anik G1 satellite module over America, Skynet offers near global coverage.

The Skynet contract allows Airbus Defence and Space to sell surplus bandwidth, through the Skynet partner programme, to NATO and allied governments, including the Five Eyes intelligence alliance members (Australia, Canada, New Zealand, the United Kingdom and the United States). As of 2020, seven Skynet satellites are operating, plus Anik G1.

The Skynet 1 to 4 series were developed and operated by the Signals Research and Development Establishment, Royal Signals and Radar Establishment and Royal Air Force until 2003. It was subsequently operated with Skynet 5 by Paradigm Secure Communications until October 2012, when the organisation was rebranded to Astrium Services then through merger in 2015 became Airbus Defence and Space.

The MOD is currently specifying a new architecture for Skynet to replace the Skynet 5 system, whose funding programme ended in August 2022. The vision for Skynet 6 is a flexible system architecture that combines UK government, allied and commercial satellites, including the current Skynet 5 satellites. Skynet is the large part of the MOD Future Beyond Line of Sight satellite communications programme (FBLOS), which extends to 2041, with expected transition costs of about £6 billion. Skynet 6A is being procured as a transition to the new architecture, but as of 2026 the exact form of the new architecture is still under discussion.

History

In the 1960s, only two countries had communication satellites, the United States and the Soviet Union. The United Kingdom created Skynet as its own military communications satellite system, because of inadequate undersea communications cable availability and to increase flexibility, reliability, data capacity and security. The Signals Research and Development Establishment led the development of Skynet 1 and 2, and its successor Royal Signals and Radar Establishment carried out research for the development of the subsequent satellites and ground terminals.

The MOD space communications research programme began in 1962, initially considering Moon and space debris bounce techniques, before considering a UK satellite. In 1964, it was decided Skynet should be in geostationary orbit over the Indian Ocean, significantly to support East of Suez deployments, and have a transponder with two channels permitting communications between two types of ground station. This would be an advance over the ongoing U.S. Initial Defense Communication Satellite Program (IDCSP). In 1965, the U.S. invited the MOD to participate in their IDCSP programme, and to participate Marconi were contracted to build three 40 foot diameter air transportable ground stations for the launch of the first IDCSP satellites in 1966. As Britain had insufficient industry expertise to build satellites, a contact was placed with U.S. Philco Ford to build Skynet 1, but with the assistance of Marconi to improve UK expertise for Skynet 2.

Nine ground stations were initially planned, which could also communicate with sub-geostationary U.S. IDCSP satellites:

• three principal stations at RAF Oakhanger, Cyprus and Singapore with 40 foot dishes and 20 kW transmitters
• two stations at HMS Jufair and RAF Gan (Indian Ocean) with air transportable 20 foot dishes and 5 kW transmitters called SKYNET V
• two additional air-transportable stations
• two Royal Navy ship stations with 6 foot dishes and 5 kW transmitters, initially installed on HMS Fearless (L10) and HMS Intrepid (L11) but movable to HMS Hermes (R12) and HMS Ark Royal (R09) as required

Skynet 1A was the first military satellite in geostationary orbit, in 1969. The Royal Air Force displayed a model of the Skynet satellite on the children's television show Blue Peter in 1969, the show also described the new British satellite control centre at RAF Oakhanger.

The Skynet satellites provided secure and encrypted facilities, though expensively, for the British armed forces and intelligence agencies. It enables an important sovereign command and control service. The largest user of the Skynet satellites during the Cold War was the Government Communications Headquarters (GCHQ), who were responsible for over 80% of traffic at some locations such as Cyprus. Despite the enormous communications capability of Skynet, GCHQ still found the capacity provided by Skynet to be inadequate. In 1972, GCHQ was still the satellite's largest funder, and argued for the purchase of an American built Type-777 (DSCS II) satellite instead. GCHQ would later plan their own secret signals intelligence satellite, Zircon, which was subsequently cancelled. The circumstances around the reporting of Zircon's existence would become known as the Zircon affair.

Throughout its models, Skynet has interoperated with U.S. and NATO military communications satellites and ground stations.

In 2010, the Civil Contingencies Secretariat of the Cabinet Office launched the High Integrity Telecommunications System, a satellite-based emergency communications service based on Skynet, for use by UK police and other emergency services, primarily for use at Strategic Command Centres and at major events and emergencies. It replaced the earlier Emergency Communications Network.

In 2021 UK Space Command was created, which when fully operational will take over responsibility for Skynet from Strategic Command (previously known as Joint Forces Command), likely in 2023. In October 2025, commander of UK Space Command Major General Paul Tedman said that Russia was attempting to jam Skynet satellites on a weekly basis, and was collecting information about them. He added that as part of the joint Operation Olympic Defender, a US satellite, likely from the Geosynchronous Space Situational Awareness Program, was moved in September 2025 to inspect and confirm Skynet 5A was operating correctly.

Models

Skynet 1

There were two Skynet 1 satellites (1A and 1B); Skynet 1A was launched on a Delta M on 22 November 1969, and stationed over the east coast of Africa. However, the satellite ceased operating after about 18 months when all of its Traveling Wave Tube Amplifiers (TWTAs) failed, probably when soldered high voltage joints failed after cycling between extreme temperatures. Some time in the mid-1970s, the now-defunct satellite was moved far from its original position; its current location in a stable "gravity well" (see Geostationary orbit#Stability) at longitude 105° W off the Pacific coast of Latin America is 36,000 km away from its original position, and it could not have simply drifted and ended up in this stable orbit. The new location is near satellite traffic and it has to be monitored for collision risks. In 2024, the BBC reported that there is no record of who moved it or why. Skynet 1B was launched on a Delta M on 19 August 1970. Skynet 1B was placed in a geostationary transfer orbit (GTO) and was abandoned in transfer orbit (270 x 36058 km) due to a failure of the Thiokol Star 17A apogee kick motor.

Skynet 1 series satellites had an orbit mass of 122 kg (269 lb), were spin-stabilised with a single despun antenna with 3 watts of output on two channels (2 MHz and 20 MHz). The North Atlantic Treaty Organization, NATO 2A and NATO 2B satellites, launched 1970 and 1971, were identical except for an antenna shaped to only cover NATO countries.

Skynet 2

Following the operational failure of the Skynet 1A satellite, the timetable for the launch of the Skynet 2 communications satellite was delayed. Skynet 2A was launched on the Delta 2313 by NASA for the United Kingdom on 19 January 1974. A short circuit in an electronics package circuit board (on second stage) left the upper stages and satellite in an unstable low orbit (96 x 3406 km x 37.6°) that rapidly decayed. An investigation revealed that a substandard coating had been used on the circuit board.

Despite being in an unstable orbit, the ground stations successfully located and tracked Skynet 2A and were able to use telemetry readings from the solar panels to determine its alignment. Based on this analysis, it was decided to use the alignment thrusters to deorbit the unit, and it was destroyed when it re-entered the Earth's atmosphere on 24 January 1974.

Skynet 2B was successfully launched on the Delta 2313 by NASA for the United Kingdom on 23 November 1974. It was positioned in geostationary orbit above Kenya to give coverage of Europe, Africa and a substantial part of Asia as far east at the Philippines. It could support about ten simultaneous users. Major ground stations used a 40-foot diameter dish, while in the field or at sea a 2 m diameter dish was used.

Skynet 2 satellites had an orbit mass of 250 kg (550 lb), with a single antenna with 16 watts of output.