Fifty years after the early warning station at RAF Fylingdales was built as the first line of defence against impending nuclear devastation, commanders say their primary mission has not changed.

The Cold War might be consigned to the history syllabus but, high on the North York Moors, the huge radar base continues its 24 hour-a-day, 365-days-a-year vigil, looking for deadly ballistic missiles heading our way.

The base, which dominates the skyline between Whitby and Pickering, is celebrating half a century of vigilance.

The remote station has other roles, including keeping a close eye on everything floating around the Earth – from old pieces of rocket to the International Space Station.

But it is first and foremost a state-of-the-art lookout for ballistic missile attacks.

Fylingdales was built at the height of the nuclear stand-off between the West and the Soviet Union and went operational on September 17, 1963.

The famous phrase “the four-minute warning” has its origins in the time Fylingdales and its sister stations in Greenland and Alaska would have allowed governments to respond to missile attack, although experts now disagree on the number of minutes the system would have given the West to decide what to do.

It was constructed on a former wartime mortar range by the United States but operated by the RAF. And, despite a substantial US military presence at the remote location, it remains a British-run base.

When it was built it consisted of three huge “golf balls” which were tourist attractions in North Yorkshire for two decades.

As radar technology evolved, the three white radomes were replaced between 1989 and 1992 with a single metallic pyramid.

This houses the solid state phased array radar which is still used today.

This radar, the only one of its kind on the world, looks out into space – 3,000 nautical miles in all directions – picking up objects as small as an apple and deciding what they are.

According to the RAF, the base has three distinct missions – warning of ballistic missile attack, space surveillance, and supporting the United States's controversial missile defence system.

Station chief Wing Commander Rayna Owens said: “RAF Fylingdales has been a ballistic missile and early warning radar site since 1963 and is delighted to be celebrating its 50th anniversary. The importance of this mission endures and some would say is even more important.

“The UK consciousness of space and our reliance on it is growing as is that of the department. RAF Fylingdales is key to this growing understanding.

“Many staff have been living and working at RAF Fylingdales for over 20 years. This provides a unique perspective and a strong connection to our community. We are exceptionally proud of the work my team has put into this tribute to the last 50 years and we look forward to the next 50 years."

Since the 1960s the RAF has stressed that the information gathered at Fylingdales in relation to missle attacks and space surveillance has been shared equally between the US and UK governments.

The base has long been the focus of anti-nuclear protesters who reject the official line that it is purely a defensive installation.

Campaign groups like CND say the role of Fylingdales makes Yorkshire a primary target for attack.