Skynet (satellites)

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This article documents a current spaceflight.
Information may change rapidly as the mission progresses.

Launch of the first Skynet satellite, Skynet 1A, by Delta rocket in 1969 from Cape Canaveral

Skynet is a family of military satellites, now operated by Paradigm Secure Communications on behalf of the UK Ministry of Defence, which provide strategic communication services to the three branches of the British Armed Forces and to NATO forces engaged on coalition tasks.

1 Models
2 Satellite summary
3 See also
4 External links

[edit] Models

[edit] Skynet 1

[edit] Skynet 2

Following the failure of one of the Skynet 1 satellites, the timetable for the launch of the Skynet 2 system was delayed. When Skynet 2A was launched on 19 January 1974, the second stage of the Delta rocket failed, placing the satellite in an unusable orbit. Despite not being in the right place, the ground stations successfully located and tracked the missing satellite, 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 27 January.

Skynet 2B was successfully launched on 23 November 1974.

The Skynet 2 satellite were assembled and tested at the Marconi Space and Defence Systems establishment in Portsmouth, England. The Skynet 2 system was very successful for its time, and remained in service for several years beyond the originally planned timeframe.

[edit] Skynet 3

Skynet 3 was abandoned in favour of the more advanced Skynet 4.

[edit] Skynet 4

Skynet 4 satellites have few similarities to the earlier generations. The cylindrical body of Skynet 1 and 2 was replaced by a large square body housing antennas with deployable solar-cell arrays. This marks the technological improvement from spin-stabilisation, used in earlier cylindrical satellites, to three-axis stabilisation using momentum wheels & reaction wheels controlling the satellite gyroscopically.

Skynet 4 were the first purely British built satellites, manufacture of 4A, 4B and 4C being carried out by British Aerospace Dynamics (BAe Dynamics). NATO adapted the design for the NATO IVA and IVB communication satellites, also manufactured by BAe Dynamics.

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 4 provides SHF and UHF services using earth cover, wide area and spot beam coverage.

[edit] Skynet 5

Skynet 5 is the next generation of satellites, replacing the existing Skynet 4 Stage 2 system. It has been contracted via PFI to a partnership between Paradigm Secure Communications and EADS Astrium, a European spacecraft manufacturer. EADS Astrium will be responsible for the build and delivery of Skynet 5 satellites in orbit, whilst Paradigm will be responsible for provision of service to the MoD. Paradigm have also been contracted to provide communications services to NATO. The first of a constellation of three Skynet 5 vehicles was launched by a Ariane 5 rocket at 22:03 GMT on 11 March 2007, aboard an Ariane 5 expendable launch vehicle and will become operational following in-orbit testing. The launch was delayed from 10 March due to malfunction of a launch pad deluge system.

The programme marks a change of approach in the UK from traditional defence procurement methods to a services-based contract which also includes provision of leased ground terminals, Reacher vehicles and Satellite Communications Onboard Terminal SCOT ship fits and the associated baseband equipment.

[edit] Satellite summary

**Summary**
Model	Manufacturer	Launch date	Launch vehicle	Comments
Skynet 1
1A	Philco Ford	22 November 1969	Delta M
1B	Philco Ford	19 August 1970	Delta M	Apogee motor failure
Skynet 2
2A	Marconi Space Systems¹	19 January 1974	Delta 2000	Rocket guidance failure
2B	Marconi Space Systems	23 November 1974	Delta 2000
Skynet 4
4A	British Aerospace	1 January 1990	Titan 34D
4B	British Aerospace	11 December 1988	Ariane 44LP²
4C	British Aerospace	30 August 1990	Ariane 44LP
Skynet 4 Stage 2
4D	Matra Marconi Space³	10 January 1998	Delta 7000	Replaced 4B
4E	Matra Marconi Space	26 February 1998	Ariane 44L
4F	Astrium⁴	7 February 2001	Ariane 44L
Skynet 5
5A	EADS Astrium⁵	11 March 2007, 22:03 GMT	Ariane 5	Launched with Insat 4B
5B	EADS Astrium	2007	Ariane 5
5C	EADS Astrium	2008	Ariane 5

Notes

With technical assistance from Philco Ford
Launched with Astra 1A, the first of the European Astra satellite constellation
Marconi Space Systems merged to form Matra Marconi Space in 1990. MMS acquired BAe Space Systems in 1994.
In 2000 MMS merged with DASA's space division to form Astrium.
BAE Systems sold its 25% share of Astrium, renamed EADS Astrium

[edit] See also

Zircon (satellite)
Skynet (fictional) from Terminator - unfortunate name coincidence for a sinister Aerospace Defense computer network in Terminator movie series, which takes over the world.