Satellite tracking

The technological challenges faced by the pioneers in satellite communications were enormous. They had to find ways of tracking relatively tiny objects in space - objects that were moving at thousands of miles an hour. And with the primitive computers of the time that stretched the technology of the 1950s and 1960s to the very limits. But their success paved the way for the 'Global Village' and introduced a new era in television.


Goonhilly - the big dish (1962) : Britain's first satellite centre
By the mid 1950s it became clear that Britain was going to need its own earth station - a dish to send and receive signals relayed via satellite. Goonhilly Downs on Cornwall's Lizard peninsula provided the ideal location for much the same reasons as it had for Marconi - on account of its clear view out over the Atlantic.
Work began in 1960 on the first steerable dish, now called Arthur (all the dishes at Goonhilly have since been named after characters from Celtic Arthurian legend). When it opened in 1962, Goonhilly was one of the first three satellite earth stations in the world and its dish was an engineering marvel.
Its design incorporated knowledge gained from the radio telescope at Jodrell Bank in Cheshire. Arthur had to be big - to trap signals from primitive satellites - and yet be very nimble, to track low orbit 'birds' as they raced across the sky. Thus this huge structure weighing 1,118 tonnes can turn a complete circle in under three minutes and can move from the horizontal through 90 degrees to the vertical.

Engineer - (getting Goonhilly built) : Mr Neil White
Neil White, born in March 1939, grew up in Cornwall. He came to London University to study electrical engineering, however city life didn't suit him and he returned to take up a post working for the Post Office Telephones at the brand new satellite station at Goonhilly in 1961.
Neil tells how Goonhilly was set up against the odds. Satellite was originally intended for military use but the Post Office and NASA had other ideas.

Engineer - (Goonhilly Visitor Centre) : Mr Neil White
Neil White, born in March 1939, grew up in Cornwall. He came to London University to study electrical engineering, however city life didn't suit him and he returned to take up a post working for the Post Office Telephones at the brand new satellite station at Goonhilly in 1961.
Neil persuaded BT to open a visitor centre at the Earth station for the public, but he remembers that the thanks to some free publicity on the radio the opening day was totally overwhelming.


BT's earth stations : A network of Teleports
Today, Goonhilly is one of five BT satellite earth stations in the UK. The other four are at Madley in Herefordshire, in London Docklands, at Martlesham in Suffolk and in Aberdeen. All are connected by fibre optic cable and overland microwave radio links to BT's nationwide broadcast and communications network.
As telecommunications moves into the new millenium there has been a worldwide shift towards the use of fibre optic cables (pioneered by BT) for high capacity point to point communications.
The movement toward fibre will never displace the use of satellites, however, due to the ease with which traffic can be configured over them - together with their lower cost on shorter routes and overall flexibility.

The development of TV satellites : clever stuff in space
Early television satellites took one signal beamed up to them from one ground station, then relayed it back over a wide area of the Earth.
Modern satellites, or 'birds' as engineers call them, are far more developed and multifunctional. They can receive signals from more than one ground station and retransmit them to various closely defined target areas.
The satellite amplifies the different 'uplink' signals, and re-transmits them on a range of 'downlink' frequencies to both home viewers and the huge receivers that serve cable television networks, known as 'head end' receivers.
Special transmitters, using multiple spot beam antennas, aboard satellites make sure the downlink signals are directed exactly at the target receivers.
Different signals can be beamed from various sections of the satellite's antenna to the different coverage 'footprints' on the ground. This targeting lets the broadcaster focus signals on specific reception areas and make the most of the power available.

Voices in orbit : explaining Satellites
Film made in 1980 which explains satellites for BT Education Services. It explained how satellites worked in sending television pictures at the time and then went on to tell the story of how international collaboration was at the root of successful development of the satellite network.