Defford Satellite Communications

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The Beginning
The Defford Satcom Facility started life at SRDE Christchurch in 1966 to support the MoD’s venture into satellite communications when it joined the US Initial Defence Satellite Communications Programme (IDCSP). The first ground station to be installed was SCAT (Satellite Communications Air Transportable Terminal). This was one of the three ground terminal built by Marconi (Chelmsford) to be deployed at MoDs strategic overseas bases. This terminal remained at Christchurch and formed the basis of the embryonic facility.
The facility at Christchurch grew in the subsequent years in order to support the growing needs of the MoD’s own Skynet programme which followed IDCSP. Terminals at SHF (7-8GHz), UHF (300MHz) and EHF (44GHz) were added. One of the main roles of the facility was to perform the initial In-Orbit testing of the Skynet 1 and 2 satellites. In addition it provided satellite access to the various satcom research projects underway at Christchurch.

SCAT & In-Orbit Test Terminals at SRDE Christchurch 1975
In the late 1970s MoD decided to rationalise its research establishments. SRDE was finally closed in 1980 and the staff and their projects were moved to what became RSRE Malvern. A new site had to be found for the Satcom Facility and after many options being considered the old Defford airfield was chosen. In most respects it was an ideal choice with many advantages including:
⦁ A 360 degree clear horizon
⦁ Electrically quiet
⦁ An East- West (the ideal direction for geostationary satellites) runway providing hard standing for the terminals
⦁ The proximity of Bredon Hill which was ideal to place the satellite simulators.
Sites closer to Malvern were eliminated because of the obstruction caused by the Malvern Hills. Originally the staff and labs were to be housed on the old RRE North Site but this was changed later and the labs and offices were built at Defford.
One of the 60 ft. antennas originally built at Defford as an interferometer and later used by RRE as a metrological radar was also incorporated as the main UHF satcom terminal. This gave a very narrow beam at the low UHF frequencies and allowed hitherto difficult tests on the Skynet 4 UHF payload to be performed. The Defford Facility was opened by the Duke of Gloucester in 1980.

Formal Opening of Defford by the Duke of Gloucester in 1980
Between 1980 and 2000 the facility grew and more terminals were added to meet the needs of both the satcom research programme, satellite In-orbit testing and MoD operational support. This latter operational support role was vital in the earlier years of Skynet as the technology was relatively new. Defford could quickly deploy its research scientists to address real time operational problems. Defford was also the fall back UK anchor station in the event of problems at RAF Oakhanger (OAKOUT) and played a major role in the Falklands, Bosnia and the two Gulf wars.
Also during this period the UK’s civil satcom research programme was initiated at Defford by the British National Space Centre (BNSC). This resulted in more terminals being constructed in the civil satcom bands at 4/6 GHz and 12/14 GHz. This idea behind the programme was to encourage UK industry to develop new civil satcom products. Its success can be judged by the following statement by Jack Leeming, Director General of the BNSC in 1988:
In the short time that the RSRE programme has been in existence it has proved extremely successful in encouraging the translation of imaginative ideas into commercial products. In particular, it has enabled some of the more adventurous and innovative small companies to participate in the development of advanced satcom equipment and gain substantial inroads into the ground segment market place.
All the In-orbit testing of the Skynet 4 series of satellites was carried out at Defford for the Skynet project office. This required all the terminals and associated equipment to be calibrated against national standards. This proved to be a major undertaking but was necessary to be able to prove that a non-compliant measurement would stand up in court if challenged.

The Defford Satcom Facility in 1985

The Defford Satcom Facility Main Control Room

Bredon Hill Satellite Simulator

Civil Satcom Research Terminals at Defford

Defford was also where most of the MoDs satcom research was undertaken. This included:
⦁ Future satellite communications payload design
⦁ Land and airborne terminals
⦁ Satellite and ground terminal antennas
⦁ Modems, including information coding and ECCM techniques like Direct Sequence and Frequency Hopping.
⦁ Satellite interference location
The research programme supporting Skynet led to many equipments entering service. These included satellite payloads, land and airborne terminals and modems. The satellite interference location service and technology, initially developed for Skynet, was later commercialised by QinetiQ and used by many satellite operators.

Prototype VSC 501 at Defford

Prototype PSC 504 at Defford Tom King visits during the Falklands War

At the End
As a result of the MoD’s decision to choose a PFI procurement approach for Skynet 5 the Defford facilities were no longer needed for operational support. This major loss of income made the facility a non-viable business and consequently it was closed in 2005 after 40 years existence at Christchurch and Defford. The Defford site was taken over by West Mercia police who are still using many of the original office and laboratory buildings.
Dick Harris
July 2018