Skynet: Ұлыбританияның әскери байланыс спутнигі жүйесі

Communications 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 MoD is currently specifying a new architecture for Skynet to replace the Skynet 5 system, whose funding programme ends 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. 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. Interim Defense Communication Satellite Program (IDCSP). 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 5kW transmitters called SKYNET V
two additional air transportable stations
two Royal Navy ship stations with 6 foot dishes and 5kW transmitters, initially installed on and but movable to and as required

Skynet 1A was the first military satellite in geostationary orbit, in 1969. The largest user of the Skynet satellites during the Cold War was the Government Communications Headquarters (GCHQ),

Skynet has throughout all its models had a good degree of interoperability 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.

There were two Skynet 1 satellites (1A and 1B); Skynet 1A was launched on a Delta M on 22 November 1969, but the satellite failed after about 18 months when all of its Traveling Wave Tube Amplifiers (TWTAs) had failed, probably due to soldered high voltage joints failing under thermal cycling. Skynet 1 series satellites had an orbit mass of , were spin stabilised with a single despun antenna with 3 watts of output on two channels (2 MHz and 20 MHz).

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 , with a single antenna with 16 watts of output. communication satellites built outside the United States and USSR. The Signals Research and Development Establishment (SRE) led the development, and performed initial in orbit testing. Subsequently, the Royal Signals and Radar Establishment supported Skynet satellites, including developing ground terminals and modems, at RAF Defford which was also a backup for the primary ground station at RAF Oakhanger.

Skynet 3 series satellites was cancelled as the United Kingdom withdrew East of Suez, and instead the capability it was intended to offer was delivered via U. S. and NATO assets. The Royal Navy was also concerned that the high frequency radio alternative enabled location tracking by the Soviet Union Ocean Surveillance System.

Skynet 4 series satellites have few similarities to the earlier generations, being based on the British Aerospace European Communications Satellite. As of 2022, Skynet 4C is still in operation, providing service to the U. S. Amundsen–Scott South Pole Station for up to six hours a day because its orbital inclination has increased to 10.3°. The Stage 1 satellites (4A, 4B and 4C) have multi frequency capability and considerable operational flexibility, with selectable channels, gain and four antenna types of differing widths to support varying requirements, Ultra high frequency (UHF), Super high frequency (SHF) and experimental Extremely high frequency (EHF) channels are available. They are hardening against electromagnetic pulse (EMP) and have anti jamming capability, with an un degraded 1600 watts power supply. The satellites have a dry mass of , with three reaction wheels and hydrazine thrusters for station keeping. The improved Stage 2 satellites (4D, 4E and 4F) were built by Matra Marconi Space and Astrium to replace the earlier versions. Improvements included increased power and resistance to electronic jamming. Skynet 4D was launched in 1998, Skynet 4E in 1999 and Skynet 4F in 2001. Skynet 4D was parked in a non operational supersynchronous orbit on 28 January 2008.

Skynet 5 is the next generation of satellites, replacing the existing Skynet 4 Stage 2 satellites. It was contracted via Private Finance Initiative (PFI) to a partnership between
Paradigm Secure Communications and EADS Astrium, a European spacecraft manufacturer. EADS Astrium was responsible for the build and delivery of Skynet 5 series satellites in orbit, whilst subsidiary company Paradigm was responsible for the provision of service to the Ministry of Defence (MoD). In 2010, the PFI contract was extended by two years to 2022, to a total cost of £3.66 billion over the course of the contract, with Paradigm able to sell bandwidth in excess of the capacity of 1.1 Skynet satellites to other allied countries. Paradigm had 220 staff and about 100 sub contractors working on Skynet. Serco is a major subcontractor on the PFI programme. This was the biggest ever outsourced military satellite communications contract. The Skynet 5 satellite is based on the Eurostar E3000 satellite bus design, weighs about , has two solar panels each about fifteen metres long, and has a power budget of five kilowatts. It has four steerable transmission dishes, and a phased array receiver designed to allow jamming signals to be cancelled out. They will also resist attempts to disrupt them with high powered lasers. Astrium described in 2010 the Skynet 5 system as: The Skynet 5 satellites have the highest powered X band transponders in orbit, a highly flexible uplink beam configuration, coupled with a world leading anti jamming antenna to ensure that the constellation is extremely effective against hostile or non hostile interference. All of the downlink beams are fully steerable and the whole payload is optimized to maximise performance for small, rapidly deployable satellite ground terminals on land, sea or air. Skynet 5A was launched by an Ariane 5 launch vehicle at 22:03 UTC on 11 March 2007, in a launch shared with the Indian INSAT 4B civil communications satellite, and entered full service on 10 May 2007. The launch was delayed from 10 March 2007 due to malfunction of a launch pad deluge system. Skynet 5A successfully separated from its launch vehicle and telemetry was acquired by its dedicated Control Centre approximately 40 minutes after launch. Skynet 5B was launched at 22:06 UTC on 14 November 2007, from Centre Spatial Guyanais, Kourou, in French Guiana, aboard an Ariane 5ECA launch vehicle. This launch was delayed from 9 November 2007 due to problems with the electronics on one of the Solid Rocket Boosters (SRB), and 12 November 2007 due to a fuelling problem with the launch pad. At time of launch, the Ariane 5ECA launcher set a new record on this mission, deploying a total payload of more than
Skynet 5C was launched at 22:05:09 UTC on 12 June 2008, from Centre Spatial Guyanais, Kourou, in French Guiana, aboard an Ariane 5ECA launch vehicle. The launch had been delayed twice. Originally scheduled for 23 May 2008, more checks were carried out on the launch vehicle and the launch was rescheduled for 30 May 2008. A problem with the launch software during pre launch checks led Arianespace to reschedule the launch for a second time to 12 June 2008. Skynet 5D was launched at 21:49:07 UTC on 19 December 2012, from Centre Spatial Guyanais, Kourou, in French Guiana, aboard an Ariane 5ECA launch vehicle. Skynet 5D provides more than double the UHF channels of the previous satellites, which are in demand as they support "comms on the move" for soldiers with backpack radios. The Ministry of Defence described the satellite as having a "key role in gathering intelligence on operations", as well as communications. Initially two Skynet 5 satellites were to be built, with insurance covering any launch loss; the MoD later decided to have a third satellite built in advance, and later still to have the third satellite launched to serve as an on orbit spare, as well as an option to a fourth satellite, as a cheaper alternative to insurance. In 2011, The MOD took ownership of a NATO satellite with two UHF channels, to support the additional demands from British involvement in the War in Afghanistan. Control of this satellite was incorporated into the Skynet 5 PFI contract. The satellites are managed from a site named Hawthorn, a few hundred metres north of MoD Corsham, in partnership with MoD's Defence Digital (previously Information Systems & Services) who are based at MoD Corsham.

In 2010, Paradigm announced it would lease the X band (SHF) module on the Anik G1 commercial satellite at 107.3° West over the Pacific Ocean, covering the Americas and as far west as Hawaii, to complement Skynet system coverage. The three channel, wide beam X band payload has performance similar to a Skynet 5 satellite, but without the military hardening. Anik G1 launched on 16 April 2013, improving the constellation's X band capacity to 2.2 GHz of throughput. In 2016, a new Australian ground station was opened at Mawson Lakes, Adelaide, managed by Airbus in partnership with SpeedCast, an Australian provider for over 25 years which works with the Australian military at that base. This complements Airbus's existing chain of ground stations in France, Germany, Norway, United Kingdom and the United States. The British High Commissioner Menna Rawlings said at the opening ceremony "Territorial disputes over uninhabited rocks and reefs have the potential to generate enough friction in international affairs to spark a confrontation", alluding to the territorial disputes in the South China Sea. Airbus Defence and Space signed a further three partners, Hughes Network Systems, Inmarsat and SpeedCast, into its Skynet partner programme who offer third party Skynet services. The Skynet contract also allow Airbus to sell surplus bandwidth to NATO and allied governments, including the Five Eyes intelligence alliance (Australia, Canada, New Zealand, the United Kingdom and the United States).

In early 1999, Reuters reported that the Skynet system was breached by a group of hackers who issued blackmail threats against the MoD. Duncan Campbell reported that the wire reports were wrong.

+SummaryModelManufacturerLaunch dateLaunch vehicleEnd of serviceGSO position in 20171BPhilco Ford19 August 1970Delta Mlaunch failureApogee motor failure, did not orbit2005Launched with JCSAT 2, re orbited in supersynchronous orbit on 20 June 200510 January 1998Delta 70002008Replaced 4B, re orbited in a supersynchronous orbit on 28 January 20087 February 2001Ariane 44L34° WestSkynet 55AEADS Astrium11 March 2007Ariane 5ECA95° East (prev. 6° East)Launched with Insat 4B. Moved in 2015 to extend Skynet coverage eastward to the western Pacific.5BEADS Astrium14 November 2007Ariane 5ECA25° East (prev. 53° East)Launched with Star One C15CEADS Astrium12 June 2008Ariane 5ECA17.8° WestLaunched with Turksat 3A5DEADS Astrium19 December 2012Ariane 5ECA53° EastLaunched with MEXSAT 3Skynet 66AAirbus Defence and Spaceplanned 2025Falcon 9 Block 5