Goonhilly Earth Satellite Station

Goonhilly Earth Satellite Station

"It's a day out of this world"

Goonhilly Downs, Helston, TR12 6LQ
Tel: (0800) 0437768


Earth Station Goonhilly is the biggest operational satellite communications centre in the world. Unlike stations in deep space, you can visit it today.

Experience the world of satellite technology. Join us in out 50 seat film theatre for a fabulous journey through time & space; operate an antenna dish for yourself, scanning the skies for television signals from all over the world, or surf the Net in our Internet Zone.

See Tristan and Isolde with their faces turned to the heavens; witnes Guinevere in silent communion with the skies. Named after Cornish Gods and legends, each of our satellite dishes has its own unique history. Merlin for instance, beamed Live Aid across the globe and the Gulf War was transmitted by Pellinor - but why not see for yourself - visit Earth Station Goonhilly today for a flavour of the past and a taste of the future.

Earth Station Goonhilly is the perfect all weather outing as virtually your whole visit is under cover. In fact, wet or misty days can enhance the Goonhilly experience. The sight of those towering, monolithic structures rising from the gloom like brooding Cornish Giants, has overawed many visitors.

Now Closed

The story of Goonhilly and its dishes etc.

Viewed from afar, Arthur, Merlin and the other dishes on Goonhilly Downs appear deceptively small. Seen close up they tower above you almost like silent monoliths in reverent contemplation of the heavens.

The dishes at Goonhilly are busy sending and receiving TV pictures all over the world, whilst simultaneously handing thousands of international phone, fax, data and video calls.

When it opened in 1962, Goonhilly was one of the first three satellite earth stations in the world.

There are now over 200 satellite earth stations scattered around the globe. Goonhilly, with a total of 25 operational and development dishes, is the world's largest.

Today, Goonhilly is one of five BT satellite earth stations in the UK. The other four are at Madley in Herefordshire, in London Docklands, Martlesham Heath near Ipswich and in Aberdeen. All five are connected by fibre optic cables and overland microwave radio links to BT's nation-wide broadcasting and communications network.

The dishes at Goonhilly focus radio energy together with the TV pictures and phone calls that ride in its back into an extremely powerful beam. This is rather like an invisible laser beam. The dishes pump the energy up at the speed of light to orbiting satellites.

The strength of the signal coming in from a satellite, although it still travels at the speed of light, is only a fraction of the power going the other way.

With the earliest satellites, this energy amounted to no more than the heat you would feel on Earth from a single-bar electric fire placed on the moon. In order to capture these very weak emissions, the first dishes at Goonhilly had to be very large indeed.

Now, as the satellites themselves become more powerful, the signals they emit are obviously becoming stronger, which means the dishes themselves are becoming smaller – though they will never be as small as a domestic receiver!

When you make or receive an international phone call, the chances are that it is routed through Goonhilly. BT handles over 10 million international phone calls each week.

Here's how it might work if you were calling New York from the UK. Your call goes though your local exchange to one of our international switching centres and on to the BT Tower in central London. From there it's transmitted by overland microwave radio links to Goonhilly.

BT systems then parcel-up your call with a host of other signals going in the same direction, and electronically label it for its correct destination.

We then beamed it up to one of the Intelsat satellites covering the Atlantic region, down to a satellite earth station outside New York. Then it passes though another international switching centre, another local telephone exchange and then on to the subscriber you want – in not much longer than it takes you to dial the number.

One of the latest applications of satellite technology at Goonhilly is the MESHSAT system. This allows commercial organisations such as banks, to operate a wide area network (covering for example, Africa and the Caribbean) that enables the transfer of financial data to and from their UK offices.

Much of the live TV material handled by Goonhilly is either news and current affairs or sporting events from around the world.

For instance, pictures of the Olympic Games come to you through Goonhilly. After we have picked up the transmissions from an Intelsat satellite we forward them to the BT Tower in London by special TV links. From there BT distributes it to TV companies throughout the UK by microwave and fibre links – all in the blink of an eye.

TV satellite transmissions from Goonhilly to other countries are mostly for foreign news agencies, sending material back home from their London bases. They book satellite space through Goonhilly by calling the TV booking centre in London whenever a big story breaks and BT allocates slots to them on a first-come, first-served basis.

As telecommunication moves towards the millennium there has been a world-wide shift towards the use of fibre optic cabled (pioneered by BT), for high capacity point to point communications.

The movement towards fibre however will never displace the use of satellites. Due to the ease with which BT can configure traffic over them together with their lower unit cost on smaller routes, and overall flexibility.

Goonhilly has remained at the forefront by complementing its satellite services with a number of international submarine fibre optic cables. Their destinations are the USA, Canada, Spain, France and the Channel Islands. Together they have the capacity to provide over a quarter of a million simultaneous telephone conversations.

Guglielmo Marconi's transmitter at Poldhu near Goonhilly sent the first live transatlantic radio message. They sent 3 dots standing for the letter S in Morse Code from to a receiver on the coast of Newfoundland in 1901.

They made the connection using radio signals of a fairly long wavelength. Such signals tend to follow the curve of the earth's surface.

Not long afterwards, amateur radio hams, using shorter radio wavelengths, found their transmissions could travel much greater distance, but not because they followed the earth's surface – quite the opposite.

They aimed their signals skywards at an angle, where they climbed to 186 miles or so. The signals were reflected back down to earth from the lower surface of the ionosphere and then back up again from the earth and so on.

Then only problem was that the ionosphere is not a reliable reflector. It changes from day to day and is severely affected by the sun, making connections mostly haphazard.

BT did not adopt England's southernmost point on the Lizard Peninsula as the site for its first satellite earth station simply because it is an area of outstanding natural beauty.

Like Marconi, whose Poldhu transmitter was only a few miles down the road, we had to have an unobstructed view across the Atlantic.

The plateau upon which we built Goonhilly gives us a view from just half a degree above the horizon. This enabled us to track Telstar (the first low-orbit satellite) that raced across the sky from horizon to horizon in under half an hour.

Like Marconi, our planners also wanted unpolluted air that was free from electrical interference.

We also had an additional requirement: we needed rock solid foundations to support our dish antennas, which would weigh hundreds of tonnes each.

Geological surveys showed that the hard, Pre-Cambrian, serpentine bedrock beneath the site, was just what we were looking for.

In 1945, a budding science fiction writer called Arthur C Clarke had a suggestion. He believed that someone could send microwave radio signals up to an unmanned orbiting satellite and beam back down again to a different part of the world.

Clarke said that we would require 3 satellites for world-wide coverage, and that the right place for them would be parked 22 miles above the Equator.

At the time, the highest human beings had been above the surface of the planet was a mere 12 miles.

The nearest thing to a satellite launcher, never mind a satellite, was the German V2 rocket, whose maximum altitude had been 46 miles; so it was hardly surprising that most people ignored Clarke's hypothesis.

Clarke had done his homework thoroughly. He had reasoned that if his proposed satellites were going to offer permanent communications links, they would have to be virtually stationary where viewed from earth, in what we call today a geo-stationary orbit.

He was spot-on. A distance of 22 miles is the optimum altitude for satellites that orbit in time with the earth's rotation, visible 24 hours a day.

At a lower altitude they would, like the early communications satellites, actually travel faster than the earth and be out of sight (and out of tough) most on the time.

The Americans launched the first two dedicated communications satellites (Echo 1 and Echo 2) into a low, elliptical orbit in 1960.

They travelled at altitudes of between 310 miles and 745 miles above the earth – crossing both the North and South Poles in the process – and took 90 minutes to complete a single orbit.

Nearly 150 feet in diameter, they looked like huge tinfoil balloons and reacted like mirrors. The signals from one satellite earth station simply reflected off them back down to another satellite earth station.

Unfortunately, thousands of tiny meteorites struck these 'passive' satellites and soon they became too badly pitted to be of any use.

Telstar was the next American communications satellite – launched on 10th July 1962. Goonhilly, which had opened only a few months earlier, was ready and waiting to track it.

As historic moments go, the first live transatlantic TV broadcast was a bit of a let-down. The pictures were so fuzzy and lined, it was only just possible for viewers to make out a face.

Yet it was still a milestone every bit as important as Marconi's first three dots to Newfoundland.

On hand at Goonhilly to record the moment for posterity at precisely 2.44am on the following day, 11th July 1962, was the BBC's Tomorrow's World presenter Raymond Baxter. His commentary went: 'Here we are … there is a bar … that's a man's face … there it is!' He was doing his best to describe the face of American telephone company boss Frederick Cappel.

Although the quality of the pictures from Telstar did improve, the most striking thing about that first broadcast for the majority of people, was the novelty of watching live TV images from beyond the Atlantic.

It did not matter to viewers that Telstar was a low-orbit satellite that disappeared from sight after 22 minutes, severing communications links until it re-appeared 90 minutes later!

By this time the feasibility of Clarke's idea of bouncing microwave radio signals off a high-orbit satellite had been proved by scientists at the Jodrell Bank Radio Telescope. They used the most obvious natural satellite for their experiments – the Moon.

All that was missing was the rocket-power to catapult a satellite into geo-stationary orbit!

Early Bird (later renamed Intelsat 1) launched in 1965. Perched 36,000 kilometres above the earth, as so accurately predicted by Arthur C Clarke 20 years earlier, it was the first geo-stationary satellite to cover the Atlantic region.

Not only were we able to track the satellite for 24 hours a day, we did not have to keep moving our dish around at breakneck speed to follow it. We hardly had to move the dish at all, as the satellite was always hovering in approximately the same position in the sky.

In practice, small dish adjustments were necessary from time to time. The method has not changed over the years. The satellite sends out a continuous beacon signal to the dish. If the satellite changes position for some reason, the dish will move and automatically follow the beam. It's as simple as that!

Intelsat 1, designed to handle 240 two-way phone calls simultaneously, or one TV broadcast, was under 3 feet in height, weighed 56 pounds, and was small enough to fit into the boot of a car.

Following it into space were the other two geo-stationary satellites that Clarke prophesied for global coverage. The first over the Pacific in 1967 and the other above the Indian Ocean in 1969. This was just in time for the whole world to watch live coverage of the Apollo 11 moon landing!

There have now been seven generations of Intelsat satellites and several satellites within each generation – each more complex than its predecessor.

There are, for example, 11 satellites in the Intelsat V series – the most powerful of which can carry 15,000 two-way phone calls and two TV broadcasts simultaneously.

The first Intelsat VI satellite came into service in 1990. As tall as a double-decker bus and weighing a hefty two tonnes, it can handle 44,000 two-way phone calls and three TV broadcasts at the same time.

Although low-orbit satellites are not suitable for permanent communications links, many are still being used for other purposes.

Eurosat, for instance, sends meteorological data to Goonhilly four times a day for 15 to 20 minutes at a time. BT then feeds this information into its nation-wide communications network and picked up by schools all over the country.

The growth in demand for satellite communications over recent years had been literally astronomical, with the result that several new services are now available through Goonhilly.

For example Inmarsat (the International Maritime Satellite Organisation) enables over 30,000 vessels at sea to communicate by phone, fax, data and telex. It also provides vital meteorological and emergency services and has revolutionised maritime communications. For example, it is now possible to dial direct to ships at sea from your phone at home.

Then there is Skyphone, which allows aeroplane passengers to make phone calls anywhere in the world.

Passengers in private jets used to be the only ones who could benefit from this service. However, a number of international airlines like British Airways, and Virgin Atlantic has have bought Skyphone to use on commercial flights for data reporting. Other facilities such as interactive sales and entertainment are being extended to passengers.

The engineering centre at Goonhilly is responsible for providing operational support for all BT's satellite earth stations. It is also innovates in the field of satellite communications.

For instance, they were the first to demonstrate radio-paging by satellite and, in partnership with British Airways, the first Skyphone tests.

Like most businesses in Cornwall, Goonhilly gets its power from the mains.

In the event of a power cut, un-interruptible power supplies keep all essential equipment going by using batteries permanently charged-up by the mains.

If necessary, these huge batteries (known as accumulators) would keep us going for at least half an hour. Our own powerful diesel generators will cut in within a maximum of 20 seconds of supply failure. The engines could keep services going almost indefinitely.

Hanging like spiders on an intricate metal web, the paint team at Goonhilly spends most days on a job that has already lasted for over 30 years. It involves steam-cleaning, priming and putting two top coats of chlorinated rubber marine coating on each dish in turn. This protects them from rust, and the ravages of the Cornish sea air that sweeps in from the Atlantic across the

Built just outside the perimeter surrounding the earth station, our Visitor Centre enhances the Goonhilly experience.

There is a 50 seat film theatre featuring a fabulous journey through time and space. Our newly installed Internet Zone is an ideal springboard from which to surf the net. You can even operate a TV antenna for yourself, searching the skies for television signals from all over the world.

BT also provides earth shuttles for tours of the station, driving close to the dishes themselves.

English Nature purchased the downland surrounding Goonhilly in 1976 as Cornwall's first nature reserve.

BT takes its environmental responsibilities very seriously and works closely with English Nature to preserve the natural character of the downland for which we are responsible.

We have planted local heathers, gorse and willow on our site, which is now a secure home to some of the rarest plants in Britain, including the fragrant orchid and hairy buttercup.

The greenery and flowers attract a variety of butterflies, insects and other wildlife which have made Goonhilly Satellite Earth Station their territory as much as ours. Even the birds that occasionally nest in the rear of our dishes are welcome visitors!

Call it coincidence if you like, but on the edge of the Goonhilly site, there is a standing stone that, like our dishes, points skywards. Unlike them, it has not been here for a mere 30 years. Archaeologists reckon it's stood for more than 6,000 years, weighs about 15 tonnes and, judging by the rock type, someone dragged it here from at least 20 miles away.

What was the purpose of these standing stones, of which there are many examples in Cornwall? The most common theory is that Neolithic inhabitants erected them so that they could communicate with their gods...

Arthur was the first dish opened at Goonhilly in 1962 using knowledge and design assistance from Jodrell Bank in Cheshire. It weighs 1,118 tonnes and has a diameter of 85 feet. Designed to work with the fast orbiting Telstar satellite Arthur can turn a complete circle in under three minutes and can move from the horizontal through 90 degrees to the vertical.

Nowadays of course, it does not need to follow Telstar across the horizon at breakneck speed and in 1964 Arthur was re-profiled with a new 'skin' of 24 petals. This allows it to receive the weaker signals for Intelsat 1 (or Early Bird) and the later geo-stationary satellite orbiting at much greater distances from the Earth. Now Arthur carries cable traffic if an Atlantic or Indian Ocean undersea cable is damaged, or to carry temporary circuits for special events like the Olympic Games.

Some say Guinevere is the most elegant of Goonhilly dishes. With it tapered tower and great beams behind, this dish reminds many people of a windmill. Opened in 1972, weighing 356 tonnes, it has a diameter of 32.3 yards and faces an Intelsat satellite hovering over the Indian Ocean. Countries served include Australia, China, Hong King, Iran, Japan, Korea, Singapore and India.

Uther opened in 1968, and with a diameter of 29.9 yards, Uther is similar in size to Arthur. It rotates a moving weight of 960 tonnes. This is through an arc of 270 degrees on a small track powered by two 15 horse power DC motors. As all our communications satellites orbit at fixed points around the equator, the antenna never needs to turn to face North. Therefore the gap in the track to the rear of the antenna allows entry of heavy maintenance equipment.

Uther serves the Intelsat satellites over the Atlantic and handles mostly phone and data transmissions. Countries served include Barbados, Brazil, Canada, Colombia, Costa Rica, Israel, The Ivory Coast, Jamaica, Mexico, Nicaragua, Peru, Jamaica, Mexico, Nicaragua, Peru, Nigeria, Trinidad, Uruguay, The United States, Venezuela and Ghana. Recent events handled by Uther include the Rugby World Cup and Test Cricket from South Africa.

Lancelot was originally designed and built in 1978 to operate to the European Space Agency's Orbital Test Satellite, it was soon in full commercial use. Helping to cope with the big increase in transatlantic traffic it now carries a range of business traffic such as video conferencing, telex and fax transmissions. This 20 yard dish is also a stand-by antenna to Merlin.

Geraint works as a maritime service link to the Inmarsat satellite over the Atlantic. The Inmarsat network allows ships at sea to communicate by telephone, fax or telex. Nearly 80% of the world's shipping can link directly with this dish, which came into service in 1982 and has a diameter of 15.5 yards.

Although Merlin is the largest dish on the site, with a diameter of 35 yards, it is also one of the lightest for it size. Made from an aluminium alloy, it weights just 395 tonnes. It also happens to be one of the most sophisticated aerials in the world. Opened in 1985, it carries four times the normal amount of traffic (using four wavelengths at once) on transatlantic routes. It's unofficially known as Blue Peter, after the children's TV programme that featured its official opening. This antenna carried the Live Aid Concert in 1985 to over 2 million million people in about 100 countries throughout the world and carried news of the assassination of the Israeli President, Yitzhak Rabin.

Tristan opened in 1983 and originally used for TV services, this 14.2 yard dish carries news from Europe and the Middle East to New York and then onwards to the North American networks. It underwent a complete refit in 1988 for use with the Skyphone service.

There are several other smaller dishes at Goonhilly. BT reserves these for operations support and tests on quality for new services by the Goonhilly engineering centre. Two worth noting are Pellinor whose base BT constructed from a World War II battleship gun turret and Percival the Offset Gregorian aerial. This has a distinctive arm with a small reflector at the end. This design allows far greater precision and efficiency in signal transmission, because the support structure of the main reflector is not in the path of the microwave beam, as it is with the other dishes.

The dishes 14, 24 and 25 provide access to the Inmarsat Maritime satellites in the Atlantic Ocean, West and East Regions. Dish 14 being configured as a traffic stand-by ready to take over from either of the others if required. BT completed dishes 24 and 25 to take over the mobile services from Tristan and Geraint in 1996. BT built dish 14 as a stand-by in 1992.

Dishes 30 and 32 are installed on the lower part of the microwave tower as part of the Meshsat system in 1995 provides wide area computer data networks for companies such as international banks.

On 12th September 2006, BT announced it would shut down satellite operations at Goonhilly in 2008, and move them to Madley Communications Centre in Herefordshire, making that centre BT's only earth station.

Until Easter 2010 the site had a visitor centre inside which the Connected Earth gallery told the history of satellite communications. There were many other interactive exhibits, a cafe, a shop and one of Britain's fastest cybercaf├ęs. There were also tours around the main BT site and into the heart of Arthur. At its prime, the site attracted around 80,000 visitors a year, but in March 2010 BT announced that the visitor centre would be closed for Easter and beyond, and until further notice.

On 11th January 2011 it was announced that part of the site is to be sold to create a space science centre. This will involve upgrading some of the dishes to make them suitable for "deep space communication with spacecraft missions". A new company has been formed to manage the operations, Goonhilly Earth Station Ltd. The company will lease most of the antennas for at least three years with the option to buy the entire complex in the future. Goonhilly Earth Station Limited took ownership of the site in January 2014.

Helston       Lizard Peninsula       Mullion       Marconi Visitors Centre