Cobra Mist

Cobra Mist was the codename for an Anglo-American experimental over-the-horizon radar station at Orford Ness, Suffolk, England (grid reference TM450511). It was known technically as AN/FPS-95 and sometimes referred to as System 441a; a reference to the project as a whole.

Cobra Mist was part of a small number of "Cobra" long-range surveillance radars operated by the U.S. Cobra Mist was originally intended to be mounted in Turkey and offer coverage of most of European Soviet airspace. When Turkey objected to the site it was moved to the UK and sited to offer a view of most of western Europe. Built through the late 1960s and into 1970, when the system was first turned on it proved to be plagued by noise problems that could not be identified and the project was shut down in 1973.

The site and buildings were then occupied by a radio transmitting station used mainly for the UK Foreign Office and the BBC World Service until 2011. In August 2015 the site and all the facilities previously held by the UK Foreign Office and the BBC (and prior to them the Ministry of Defence) were acquired by Cobra Mist Limited, a privately owned company. The main building and 12 towers remain. Five are 340 feet high.

Cobra Mist was based on the Naval Research Laboratory's experimental MADRE radar, which was able to reliably detect aircraft at ranges up to 2,000 nautical miles (3,700 km) from its base in Chesapeake Bay. With prior setup, MADRE was even able to detect rocket launches at Cape Canaveral and atomic tests in Nevada.

With this successful demonstration, the US Air Force started plans to deploy a similar system in Turkey; providing coverage of much of the western part of the Soviet Union. Tenders for the system outline were placed in 1964 and bids followed the next year for the actual system itself. However, Turkey refused to provide a base for the system and a search started for a new location.

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