Perhaps most non-technical people, if asked what they know about ‘Telstar’, would probably say it was a number one instrumental chart hit composed and produced by Joe Meek and played by The Tornados.

Pop music buffs may even know that it was recorded at RGM Sound in London and released on August 17th, 1962 with ‘Jungle Fever’ featuring on the B side. This may all be true, but avid readers of RadioUser will also know that Telstar was a telecommunications satellite, which provided the first-ever ‘live’ television transmissions between America and Europe in 1962.

‘Telstar’ was, in fact, a more generic name for various telecommunications satellites. The first two Telstar craft were virtually identical, and both were launched purely for experimental tests. The craft we are focusing on in these articles was called ‘Telstar-1’. It was launched atop a Thor-Delta rocket on July 10th, 1962, from the Cape Canaveral Air Force Station in Florida, USA (Fig. 1).

The spherical satellite had a diameter of 88cm (approximately 35 inches) and weighed 35kg (approximately 77lbs). Its successor, Telstar-2, was launched a year later on May 7th, 1963.

Telstar was by no means the first satellite to be placed into orbit. That honour went to the former Soviet Union when it successfully launched Sputnik-1 (or Спутник-1, in Russian) which literally means ‘companion’ or ‘satellite’ in the astronomical sense.

This was the World’s first artificial (that is, man-made) satellite, and it measured only 58cm (22.8 inches) in diameter. It weighed 83.6kg (183.9lbs in old money) and its elliptical path took approximately 98 minutes to orbit the Earth.

USSR: First into Space

It was on October 4th, 1957, when the world of telecommunications made a giant leap forward. The Soviet Union had successfully launched Sputnik-1 and, in the process, had beaten the USA in the space race. The satellite didn’t actually do very much; it mainly transmitted just a series of regular radio beeps and limited data, but it was the first step towards telecommunications from space.

Sputnik-1 was launched from what is nowadays known as the Baikonur Cosmodrome at Tyuratam (370km south-west of the small town of Baikonur) in Kazakhstan – then part of the former Soviet Union (Fig. 2).

The idea of placing geostationary (rather than orbiting) communication satellites into orbit around the Earth was first promulgated by the famous mathematician and author, Arthur C. Clarke, in his article published in the technical magazine, Wireless World in February 1945. Some 32 years later, the authors of this article too were privileged to write a series of articles for Wireless World.

However, the notion of launching satellites (not necessarily ‘geostationary’ craft) was actually discussed as far back as 1885, when Konstantin Tsiolkovsky first described in his book, Dreams of Earth and Sky, how a satellite could be launched into a low-altitude orbit.

A geostationary satellite is one which is placed in an equatorial circular orbit at a distance of approximately 42,164km (26,205 miles) from the centre of the Earth. This equates to a distance of approximately 35,787km (22,242 miles) above mean sea-level. The satellite would have an orbiting period equal to the Earth’s rotation on its axis.

One sidereal day equals 23 hours and 56 minutes (rather than the easier time period of 24 hours in a day which everyone is familiar with). The satellite would, therefore, remain geostationary over the same point on the Earth’s equator. This is known as the Clarke Orbit.

Solar Cycles

The idea of launching research satellites officially began in 1952. The International Council of Scientific Unions decided to inaugurate the International Geophysical Year (IGY), which would run from July 1st, 1957, until December 31st, 1958. This period was specifically chosen because the solar cycle would be at its maximum.

High activity in solar cycles usually produces a massive increase in the number of sunspots and solar eruptions. This phenomenon was of particular interest to DX-TV enthusiasts, as standard broadcast television signals could be received from transmitters located thousands of miles away during high solar activity. This occurs approximately every eleven years, in line with the sunspot cycle.

It was decided in October 1954 that man-made (or ‘artificial’, as physicists prefer to call them) satellites should be deployed during the International Geophysical Year 1957/58, in order to map the surface of the Earth.

www.nas.edu/history/igy

Technical experts in the USA were given the task to develop such a craft before the Russians did. Consequently, in July 1955, the White House boasted to the World that, following exhaustive meetings and discussions with a plethora of government research agencies, the manufacture of an orbiting satellite would be complete in time for the IGY.

The USA Naval Research Laboratory was chosen to produce the Vanguard system in September 1955. The craft was designed to have a payload of 1.59kg (3.5lbs).

Everything seemed to be in place for the Americans to beat the Russians in the space-race.

Unfortunately, the American dream was turned into a nightmare, when Russia launched their Sputnik-1 satellite on October 4th, 1957 (Fig. 3). This craft was smaller and more advanced than the American Vanguard design. Sputnik-1 remained in orbit until January 4th, 1958, then it re-entered the Earth’s atmosphere and burned up.

Sputnik-2 Launched

It wasn’t too long before the American government, and the general public realised that rocket technology employed to launch a satellite (which was originally intended to simply map the Earth’s surface) could easily be modified to send ballistic missiles which could carry nuclear weapons from Europe to the USA.

Before anyone had had time to digest all the implications, the Russians struck again. Sputnik-2 was successfully launched on November 3rd, 1957. This had a much heavier payload and in amongst the huge glowing thermionic valves and sparking coils which Russian equipment manufacturers seemed to love until around the 1980s, there was even room for a dog called Laika. It’s not certain whether sufficient tins of Winalot were on-board (or if the Russians had remembered to pack a tin-opener!) but sadly, Laika didn’t survive long enough to admire the splendid views from space.

Laika’s real name was Kudryavka (or Little Curly), but a Russian word which embraced all dog breeds similar to a husky was picked up by the international press. Similarly, the elephant who disgraced herself ‘live’ in the Blue Peter studio (with Valerie Singleton, John Noakes and Peter Perves) wasn’t really called ‘Lulu’ – but we digress.

It wasn’t too long before American reporters dubbed Laika as ‘Muttnik’! The orbit of Sputnik-2 decayed and re-entered the Earth’s atmosphere on April 14th, 1958, after 162 days in service.

The First Man in Space

The USSR was also ahead of USA when they launched the first man into space. Yuri Alekseyevich Gagarin was a Soviet pilot and cosmonaut. He made space history when his Vostok-1 spacecraft completed one orbit of the Earth on April 12th, 1961.

On his return to Earth, he was greeted by the jubilant leader of the Soviet Union, Nikita Khrushchev. Television coverage of the welcome home was broadcast to viewers throughout Europe via Intervision and Eurovision (Fig. 4).

Sputnik-1 Construction

Sputnik-1 was the first in a series of four satellites to be part of the Soviet Union’s programme of space exploration. Three of these satellites (Sputnik 1, 2 and 3) reached Earth orbit.

The Sputnik-1 satellite consisted of an aluminium sphere, 58.0cm in diameter, that carried four whip-like aerials, which were 2.4 to 2.9 metres in length (Fig. 5).

The whisker-like aerials were directed towards one side. The spacecraft gathered various data, including the density of the upper layers of the atmosphere and the propagation of radio signals in the ionosphere. The instruments and electric power sources were housed in a sealed capsule.

This also included transmitters which operated at 20.005 and 40.002MHz (about 15 and 7.5m in wavelength). The duration of the emissions was arranged in alternating groups of 0.3 seconds. The downlink telemetry included data on the sphere’s internal and external temperatures.

The sphere was filled with nitrogen under pressure and provided the first opportunity for meteoroid detection (not that any such events were reported) because losses in internal pressure, due to meteoroid penetration of the outer surface would have been evident in the temperature data. The satellite transmitters operated for three weeks, and the data was monitored with great interest around the World until the onboard chemical batteries expired.

The orbit of the subsequently inactive satellite was then observed optically. The orbit decayed 92 days after launch (on January 4th, 1958) after having completed about 1,400 orbits of the Earth over a cumulative travelled distance of some 70 million kilometres. The orbital apogee declined from 947km after launch to 600km by December 9th.

RadioUser readers will, of course, instantly recall that the apogee denotes the furthest distance from the Earth of an object orbiting the planet, which is not to be confused with the perigee, which is the closest distance and is the stage at which the Moon appears larger. It’s amazing what you can learn in this magazine!

From this prototype, thousands of satellites have been launched in Earth-orbit since the 1960s, mostly for military, scientific and telecommunications purposes.

The Sputnik-1 rocket booster also reached Earth orbit and was visible from the ground at night as a first magnitude object. Meanwhile, the very small but highly polished sphere, barely visible at sixth magnitude, was more difficult to follow optically. In astronomical terms, the magnitude scale is a logarithmic system in which an integral step corresponds to a change of approximately 2.5 times in brightness. The magnitude scale was devised by the Greek astronomer and mathematician, Hipparchus, who designated the brightest stars as ‘first magnitude’ and the faintest as ‘sixth magnitude’.

A replica of the Sputnik-1 satellite was placed on display in the Smithsonian National Air and Space Museum in Washington, D.C. as well as various museums in Russia.

In Part Two, we will be looking in some detail at the first ‘live’ television transmissions between the USA and Europe, and we will offer nothing short of a brief exploration of the Universe!

This article was featured in the March 2019 issue of Radio User