Sputnik, the first artificial satellite
By Théo Pirard
It was thus that, on the night of the 4th and 5th October 1957 an instrument, then mysterious, was launched from an equally mysterious corner of Central Asia. In fact it was not until 1961 that the Baikonur cosmodrome, close to the city of Lenin-Tiouratam in the Kazakhstan steppes, was revealed to the public. The device launched fifty years ago was the first artificial satellite, called Sputnik-1. This Russian word means ‘travelling companion’: following the example of the Moon, this first satellite kept the company of our planet on its journey around the Sun.
A lifespan of three months
Sputnik-1 was placed in orbit by a Semiorka rocket – during what was then its fifth flight, the previous two having been successful – in its intercontinental missile R7 version. With a take-off mass of 280 tons – 9/10 of which were made up of propellant fuels – it provided the PS-1 satellite with a speed of 28,000 km per hour (7.8 km/s) And this at the end of a powered flight of hardly five minutes duration to stay on course for space! In ejecting the cap its central stage released a 0.58m steel aluminium sphere, pressurized with nitrogen and bristling with four long antennae: the first Sputnik. This glistening ball weighed 83.6kg, of which two thirds was made up of silver-zinc batteries. Placed in a terrestrial orbit between an altitude of 228 and 950km, the satellite carried out its journey in free-fall: it ‘fell’ whilst making circuits of the planet.
Audible, if not visible
In Moscow the Kremlin rulers, with Nikita Khrushchev at their head, were not expecting the mission to succeed at the first attempt. They were caught on the back foot by the shockwave effect Sputnik had on worldwide opinion. They nevertheless understood very quickly that the Soviet regime had, with this cosmic première, in its hands a propaganda weapon in the cold war that saw it confronted by the United States. And the stares fixed skywards in order to see this ‘baby-moon’ passing overhead: but the object that sparkled in the sun was the Semiorka rocket stage, with a length of 28m. Whilst it was invisible, Sputnik-1 nonetheless made itself heard: its strident ‘bip-bips’, beamed out by two transmitters at 20 and 40 MHz (15 and 7.5 longwave), could be captured by radio enthusiasts over the entire world. The data transmitted by this first satellite were the sphere’s internal and external temperatures, and they were used to analyse the spread of signals in the ionosphere.
Barks in the cosmos
The team of engineers and technicians – Russian and Ukrainian – who had succeeded in the feat of launching the satellite had not finished furnishing surprises and sadness. At first, in the words of Oleg Ivanovsky, deputy-designer of the Sputnik mission – who is today 85 years old – these shadowy workers were upset at having been in some way deprived of the confidentiality of their work: what was supposed to be a state secret at the heart of the military-industrial complex found itself on the front pages the world over!
In the face of the Soviet Empire’s space performances, made possible by the power of the Semiorka rocket, the Americans took fright. They were aware that Moscow had available an intercontinental missile with a range of 8.000 km, capable of striking North America with a nuclear weapon. Their pride had taken a blow: Russian was being spoken in the cosmos! Washington tried to save its honour in December 1957 by launching a micro-satellite, weighing 1.5km, which resembled a grapefruit (from whence its name). But the US Navy’s small Vanguard rocket crashed during its Cape Canaveral lift-off, which was given a lot of media attention. And the newspapers headlined with bitter irony: Flopnik! Kaputnik! The humiliation was at its peak.
The price of a gold bar…
Space exploration has granted respectability and nobility to rockets, the heirs to V2 and other missiles of destruction. They regularly place satellites in orbit around the Earth for scientific missions, telecommunications, television, navigation, observations of the planet, etc. It is they that enable manned spaceflight and which dispatch probes to the Moon, the planets Venus and Jupiter, and as far as the edges of the solar system. Interplanetary probes such as Voyager, which, on route to the stars, find themselves at tens of millions of kilometres from our Earth.