Throughout history, one of the most important terrain types to occupy in battle was high ground of some sort, be it a hill or a ridge line. In the 20th century, the new ‘high ground’ is space, and since the end of WW II, the race has been on to exploit this new medium for military advantage.
On 3 October 1942 Nazi scientists launched an A-4 rocket that travelled a distance of 118 miles (190 km) and reached an altitude of 50 miles (80 km). But it was not until the 1950s that the true potential of space began to dawn on both the politicians and the military. On 4 October 1957 the West was stunned to learn that the USSR had placed an artificial satellite (Sputnik-1) in orbit around the Earth, and that the object weighed 183 pounds (83 kg), dwarfing the 20 pound (9 kg) package that the US navy was planning to send up on its Vanguard rocket. A double blow ensued with the launch of Sputnik-2, which carried into orbit a dog called Laika, on 3 November 1957 and weighed 1, 120 pounds (508 kg).
The American space race started with the launch of the small 10½ pound (4.8 kg) Explorer-1, on a Jupiter rocket on 30 January 1958, discovering the Van Allen radiation belts. This was followed up by the launch of SCORE (Signal Communication by Orbiting Relay Equipment) on an Atlas rocket on 18 December 1958 (it carried a taped Christmas greeting from Pres Eisenhower) and Discoverer-1 on 28 February 1959, not from Cape Canaveral, but from Vandenberg Air Force Base.
The 1960s saw an intensification of the space race, as both sides by now realized its potential. While the USA had some notable achievements such as having the first reconnaissance, meteorological, communications, and navigation satellites, the Soviets had even greater successes with the first manned space capsule in orbit (Yuri Gagarin in Vostok-1 on 12 April 1961), as well as the first space walk by Alexei Leonov, from Voskhod-1, in March 1965. The fact that the Soviets seemed to be ahead dented American pride, and was also a cause for concern since it also implied a lead in heavy missile capability as many rockets were modified ICBMs and could therefore be used to strike targets anywhere on the globe. John F. Kennedy stated in October 1960 while running for the presidency: ‘Control of space will be decided in the next decade. If the Soviets control space they can control Earth, as in the past centuries the nations that controlled the seas dominated the continents.’ As its Gemini and then Apollo programmes progressed, the USA began to rehearse the techniques and test the equipment with which it would send a manned vehicle to the moon. Finally, on 21 July 1969, Neil Armstrong became the first man to set foot on the moon.
During the 1960s and 1970s the number of launches per year by both sides increased to a peak of 55 for the USA and 66 for the USSR, and then gradually tailed off, as satellites became more reliable and had longer endurance. Both countries continued sending probes out to the far reaches of the solar system; both started to develop a manned space station programme (Skylab and Salyut) and look at the possibility of a lifter that could be reused time and time again. This culminated in the launch of the US Space Shuttle on 12 April 1981. The space shuttle rode into orbit on booster rockets and then re-entered the Earth's atmosphere to land like a conventional aircraft.
The main military use of space has been to field increasingly sophisticated satellite systems to support operations on Earth. In many ways, satellite-based systems have superseded their ground-based counterparts, causing these other systems to atrophy. This is because space-based systems can accomplish the mission in a superior manner and are more economical. Indeed, the Gulf war, which could be seen as the first ‘space war’, confirmed that space-based technology gave the western powers a substantial force multiplier. Military activity is now almost unthinkable without the exploitation of space-based systems for surveillance, navigation, and targeting.
Orbital dynamics depends upon gravity, and so Newton's Law of Universal Gravitation comes into play. In simple terms, the force of gravity affecting an object is proportional to how far away it is. To stay in a circular orbit, the speed a satellite needs to reach depends upon its distance from the Earth. The lowest orbits require a velocity of 5 miles/sec (8 km/sec) while that of 60 Earth radii (the distance of the moon) would only require a velocity of 0.6 miles/sec (1 km/sec). Alternatively, the satellite could be launched into an elliptical orbit, with the closest point to the Earth known as the perigee, and the furthest, the apogee. Both types of orbits have to operate under Kepler's laws of orbital motion. The first law states that the orbit of a satellite is an ellipse, and that one of the foci of the ellipse must be located at the centre of the Earth. The second of Kepler's laws states that a satellite in orbit will have an imaginary line joining it to the centre of the Earth that sweeps equal areas in equal time. The satellite will thus be altering its speed at different times in its orbit and will have a maximum speed at perigee and minimum at apogee. Of course, all would be fine if the Earth was a perfect sphere, but it is in fact a slightly flattened sphere. This introduces complications in determining the best orbit for a satellite.
Space-based assets are not available to all countries, and are not evenly spread among those who have them. Space technologies are complex and well beyond the budget of most countries, in that developing a reasonable military communications satellite system could cost in the region of £1 billion. In the era of shrinking budgets, space systems have to compete with front-line equipment, research and development, and personnel costs. The two superpowers are the only two that acquired the full range of space capabilities (and Russia still matches the USA for this). There are a number of distinct uses that satellites can be put to. Communication satellites provide tactical and strategic real-time communications with forces around the world, and as sensors and weapon-system ranges increase so this importance will continue to grow. In fact, over 70 per cent of America's overseas military communications is relayed by satellite. The main systems in this area are the USA's Defense Satellite Communications System; US air force and navy's AFSATCOM and FLTSATCOM and the Satellite Data System; the Soviet Molniya (‘Lightning’), and Volna (‘Wave’) systems; and Britain's Skynet (Skynet 1, being the first geostationary military communications satellite, launched in November 1969). Most communications satellites use ‘geostationary’ orbits which entail a highly elliptical orbit, and involve an apogee of 22, 370 miles (36, 000 km) which is approximately six Earth radii. At this distance, the satellite appears to stay in the same position when viewed from Earth. These systems use a variety of frequency bands, UHF (300 MHz-3 GHz), SHF (3-30 GHz), and EHF (30-300 GHz), each of which has certain advantages and disadvantages. Reconnaissance satellites cover the areas of photo-reconnaissance, ocean reconnaissance, and SIGINT. Photo-reconnaissance satellites cover much of the electromagnetic spectrum (infra-red, ultra-violet, radio, radar, and visible light) and the resolution that these satellites are capable of is the most important feature, and one that has been improving constantly. SIGINT satellites are known as ‘ferrets’ and try to locate radio transmitters, eavesdrop on radio communications, and monitor telemetry from missile tests. The best-known systems are the USA's Keyhole and ‘Bigbird’ satellites and the Soviet Kosmos system. Weather satellites carry a battery of sensors to record atmospheric conditions, including a line-scanning radiometer (which records visual and infra-red imagery), infra-red temperature-moisture and microwave sounders (to measure precipitation), a precipitating electron spectrometer (for forecasting the location and intensity of the aurora borealis), and an ionosphere sounder (to measure the electron distribution in the upper atmosphere). Early warning satellites include those designed for the early detection of ballistic missile launches and those that detect nuclear explosions. They tend to have focal-plane array telescopes with infra-red sensors to detect the heat exhaust of a missile, or atmospheric burst sensors which detect the visible light, x-ray, and electromagnetic pulse emissions of a nuclear explosion. The USA operates these systems on the DSP (Defense Support Program) satellites in geosynchronous orbit and the new Navstar navigation satellites, while the Russians have a constellation of nine satellites in a highly elliptical orbit inclined 63 degrees to the equator. Finally, navigation satellites have been in use since the early 1960s, initially for warships and submarines (the American systems known as Transit and Nova, while the Soviets used Navsat). The early satellite systems have been superseded, however, by a new generation (Navstar GPS and Glonass) which travel in circular semi-synchronous orbit, in six groups of four, each in a different plane with an inclination of 55 degrees. The Global Positioning System (GPS) made possible the large-scale desert movements of the Gulf war; in an earlier era, they would just have got lost. GPS has also made possible GPS-guided bombs, which navigate themselves to the desired point in three dimensions without the need for an external guidance source such as a laser, and are thus effective in all weathers.
As satellites have proved to be indispensable for the military in operations on Earth, it is very probable that these very satellites may start to be targeted by adversaries who wish to degrade the ‘force multiplier’ available to those forces that have them. This can be done by what is known as ‘cyber warfare’; that is, attacking the software in the computer systems that control the satellite itself, or those on the ground that rely on them, or by a physical assault on the satellites themselves, by ASAT (anti-satellite) weapons. Although ASAT weapons were first researched in the late 1950s and 1960s, neither side has been keen to really fund an extensive ASAT programme, probably as a result of budgetary pressures and the fear of opening up another strand in the arms race. As such, these weapons could be projectile or kinetic-kill weapons (such as an electromagnetic rail gun), lasers (such as the chemical, excimer, free electron, or x-ray types), particle beam weapons, or conventional missiles. They could either be based on Earth or launched into orbit, but some weapon types are more suitable to Earth- or orbit-based deployment than others. Alternatively, such weapons could be used for other purposes, such as a ballistic missile defence, as was the hope of Ronald Reagan's SDI or ‘Star wars’. Finally, although satellites can be thought of as relatively vulnerable (being fragile and packed with sensitive electronics), they are small, at great distances from the Earth, and travelling at high speed, and there are a great number of them to keep a track of.
Bibliography
- Dutton, Lyn, et al., Military Space (London, 1990).
- Hayward, Keith, British Military Space Programmes (London, 1996).
- Hobbs, David, An Illustrated Guide to Space Warfare (London, 1987).
- Kirby, Stephen, and Robson, Gordon, The Militarisation of Space (Brighton, 1987).
- Peebles, Curtis, Battle for Space (Poole, 1983).
- Stares, Paul B., Space and National Security (Washington, 1987)
— Peter D. Antill
