52 ideas that changed the world - 45. Geosynchronous satellites
The first launch into Earth’s orbit revolutionised global communications and TV
In this series, The Week looks at the ideas and innovations that permanently changed the way we see the world. This week, the spotlight is on geosynchronous satellites:
Geosynchronous satellites in 60 seconds
A geosynchronous satellite is a satellite with an Earth-centred orbit that takes the same amount of time as one rotation of the Earth, roughly 24 hours.
A geostationary satellite is a specific type of geosynchronous satellite. While the latter can have any inclination, geostationary satellites are in a circular orbit above Earth’s equator and following the direction of Earth’s rotation. To an observer on Earth, a geostationary satellie would appear not to move at all.
The first geosynchronous satellite was launched in 1963 and, according to Nasa, they are now used to provide weather satellite images and to communicate data back and forth between the Earth and spacecraft.
Geostationary satellites followed a year later. Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located.
How did the tech develop?
The first appearance of a geosynchronous orbit in popular literature was in October 1942, in the first Venus Equilateral story by American science-fiction writer George O. Smith.
Smith, though he did not go into detail, outlined the concept in QRM–Interplanetary, the first of the series of 13 short stories. This idea was then picked up by British science-fiction author and futurist Arthur C. Clarke.
Clarke, who went on to co-write the screenplay for the 1968 film 2001: A Space Odyssey, popularised and expanded the concept in a 1945 paper titled Extra-Terrestrial Relays – Can Rocket Stations Give Worldwide Radio Coverage?.
The paper, published in the engineering magazine Wireless World, referenced Smith’s influence, with Clarke writing: “It is… quite possible that these stories [Venus Equilateral] influenced me subconsciously when… I worked out the principles for synchronous communications satellites.”
Clarke also first described the concept of a geostationary satellite, as well as its potential application, and so the orbit is sometimes referred to as a “Clarke orbit”.
According to Discover magazine, the first geosynchronous satellite was designed by American electrical engineer Harold Rosen, while he was working at Hughes Aircraft Company – owned by eccentric billionaire Howard Hughes – in 1959.
Inspired by the Soviet Union’s launch of Sputnik 1, Rosen wanted to use a geosynchronous satellite to speed up communications. The magazine notes that prior to this, telecommunications between the US and Europe was possible between just 136 people at a time, and reliant on high frequency radios and an undersea cable.
At the time, received wisdom said that the rocket fuel required to propel a satellite into orbit, combined with the short lifespan of such a satellite, made the process too expensive. But, by 1961, Rosen had designed and built a prototype that was light and small enough to be placed into orbit, says Discover.
Two of the satellites were built – Syncom 1 and Syncom 2. The first was lost to an electronics failure, but Syncom 2 was successfully placed into a geosynchronous orbit in 1963.
The satellite was able to relay TV transmissions and, in 1963, the Los Angeles Times reports that it also allowed for US President John F. Kennedy to phone Nigerian prime minister Abubakar Tafawa Balewa from a ship.
It was not until Syncom 3 that the first geostationary satellite was successfully launched. With its increased bandwidth, this satellite was able to transmit live coverage of the 1964 Tokyo Olympics to Americans.
The LA Times says that following the launch of Syncom 3, “hundreds of communications satellites are now in the skies above Earth in geosynchronous orbit”.
In 1974, America’s first domestic and commercially backed geostationary communications satellite was launched when Westar 1 was sent into orbit by Nasa from Cape Canaveral, Florida.
The satellite was built by the Hughes Aircraft Company for financial services company Western Union, which used it for internal communications until it was retired in April 1983. Westar 1 was the first of five Westar satellites launched by Western Union between 1974 and 1982, part of a growing trend for domestic satellite launches.
At the time, The New York Times reported the launch of Westar 1 as the beginning of “a fierce commercial competition… that could drastically reduce the cost of private voice circuits and long‐distance transmission of television programs and computer data”. The prediction would come true in the decades that followed.
According to Satellite Signals, which monitors the number of satellites circling the Earth, there are 402 satellites currently in geosynchronous orbit, beaming out everything from Sky television to military communications.
The International Telecommunications Union says that 96% of the Earth’s population has access to a mobile phone network and 90% has internet access. However, some rural and remote areas in developed countries, such as America, are still reliant on communications provided by geostationary satellites, CNET adds.
–––––––––––––––––––––––––––––––For a round-up of the most important stories from around the world - and a concise, refreshing and balanced take on the week’s news agenda - try The Week magazine. Start your trial subscription today –––––––––––––––––––––––––––––––
How did it change the world?
As the LA Times says, what Rosen imagined in the late 1950s was “a revolution in communications”.
“In those days, an international telephone connection required making a reservation because the existing system carried few calls,” the paper says, adding: “Many countries could not be called at all.”
Rosen’s satellite changed all of that. It was the blueprint for the hundreds of geosynchronous satellites that currently orbit the Earth, providing communications, GPS and transmitting information from space to Earth.
As Discover magazine adds: “If Harold Rosen’s team hadn’t figured out how to send satellites to circle Earth in controlled, equatorial orbits, today we’d have no live transmission of the Olympic Games, no satellite phones in Iraq, no faxing to Hong Kong.”