It is not strictly accurate to classify space technology as a separate area for research. It is made up of a multitude of different scientific disciplines. From the chemistry of rocket propellant, through the mathematics of orbital calculations to the psychology of isolation in zero gravity conditions, no area of modern science is left unrepresented. It is however valid to consider it as a collection of new technologies directed towards the common exploitation of the vast region of the universe beyond our atmosphere. The first satellite placed in orbit was Sputnik 1 in October 1957. The implications for the strategic balance at the time were profound. Yet in the 40 years that have followed, the military exploitation of space has been more limited than early forecasts predicted.(1) . As one expert has said "The Space Age fizzled because the grand dreams turned out to be too expensive". (2)
A primary area for research was in the space vehicle provision. Single shot ballistic rockets have assumed a vital role in nuclear delivery, satellite emplacement, and have potential for conventional warfare. In this respect civil and military needs have run in parallel as the demands for communications satellites for civil use have increased. That said, the military use has in the past driven the technology, and it will continue to be a significant consideration for the future. The high cost of expendable space systems led to the development of the space shuttle by the United States. However experience of the shuttle in use has not yet given convincing proof that launch costs have been reduced. The major lesson of the first three decades in space is that the costs of breaking free from the Earth's gravity remain very high. The European Ariane 5 programme was designed to produce a cheap mass launching capability. Yet the first launch in June 1996 produced a £500 million fireworks display (3). This was a salutary reminder of the costs and risks that are still implicit in the utilisation of space. It is therefore important that whatever is done in space is provided at minimum weight, and the development of microprocessor technology has been a major factor.
Research will continue into rocket propulsion, and vehicle design, but a major breakthrough in reduction in launch costs from the Earth's surface to orbit is unlikely. It has been suggested that projectile launch systems (first postulated by Jules Verne in the last century) may offer lower cost satellite launching systems. The extra costs of hardening each very expensive satellite cannonball, coupled with the costs of building the necessary launch gun, have yet to be shown to be economic. Civil research into propulsion systems for space is focused on the system to be used once free of the earth's gravity. The five most promising techniques identified are: nuclear-electric propulsion, solar-electric propulsion, laser propulsion, solar sails, and electromagnetic ram accelerators. (4). Until warfare is transferred from the Earth to other planets, these researches are unlikely to be important to military systems.
Research has also been undertaken on the development of hybrid aircraft/rockets which can use conventional aircraft techniques to reach the upper atmosphere, from where they can launch into low earth orbit. While these developments may improve the reliability of reusable space vehicles, they are unlikely to change the payload costs much. The highest that conventional aircraft operate is at around 20 miles, and at this distance from the earth, the gravitational potential is little less than at the surface.
If the costs of raising objects from ground level to orbit are to remain high, the effectiveness of what is put into orbit is likely to be a more productive area for research. The prospects of weapons, both defensive and offensive, in space has at various times attracted considerable interest; yet all man-made devices in space today are either civil, military but non-offensive, or inert. Anti-satellite weapons have been tested, and will be considered later in this chapter. Other space-based weapon systems remain in the research laboratory. Space today is home to a range of military satellites who roles are reconnaissance, communications, navigation, meteorology, and geodetic survey.
Reconnaissance satellites exploit a wide range of the electromagnetic spectrum. Electronic intelligence can be gathered from radio and radar signals. Early warning of missile launch is gained from infra-red sensors observing the missile exhaust. The visible and near visible region can provide traditional strategic and tactical reconnaissance information. The areas for productive research to improve military capability revolve around the normal reconnaissance cycle. In this, the time between initiating the task and receiving the processed information must be as short as possible, the quality of the information must be as high as possible, and the interpretation of the data must be as accurate as possible.
The propagation characteristics of particular wavelengths of electromagnetic radiation in the atmosphere make satellite reconnaissance less than totally reliable. They can only complement an overall intelligence picture obtained from aircraft and human sources. Nevertheless improvements in sensors will improve sensitivity and discrimination. More active scanning may offer improved results. Radar or laser emitters from the satellite could illuminate specific targets. One particular area where successful research could have a dramatic effect on military effectiveness is in the detection of submarines under the ocean. Techniques being explored include high-power lasers, magnetic anomaly detection, small temperature anomaly detection, radar, and sea surface movement.(5) After many years of research, none of these seem to offer the prospect of making the oceans transparent, but they may aid submarine detection.
Reducing the time taken for the reconnaissance cycle is also amenable to novel techniques. While some satellites can be placed in geosynchronous orbit to monitor a particular area, their great distance from the surface reduces definition. If they are placed in low orbit to improve quality, then they cannot hold position over one area, and only a part of their orbit will be useful. This can be compensated for by the use of a number of satellites which weave a pattern of orbits to ensure the required level of coverage of the target. This multiplies the cost. For particular operations it may be worth launching a reconnaissance satellite into a predetermined orbit for the one mission: an expensive option. While such satellites have the ability to move orbit from their own power sources, such provision is finite and once the fuel is exhausted they will soon decay and burn up. It is possible to envisage drone satellites being launched from a space station for particular missions, and recovered at the end of the task for refuel. It is not obvious that the benefits would outweigh the costs, unless the space station were justified on other grounds.
The utility of a space station is something which is worth examining separately. Many future projections of military use of space start from the assumption that such a platform will be available. By space station, it is generally assumed that this would be a continuously manned orbiting structure, which allowed a range of space tasks to be carried out, with regular replenishment from the Earth. Without specifying the nature of the platform, costs are inevitably speculative. Van Allen suggested a figure of $30 billion (1984 dollars) for the NASA station which was then proposed for 1993.(6) The Soviet Union was at the forefront of research into prolonged manned spaceflight, and operated rudimentary manned space stations with docking facilities since Salyut 1 in 1971. The current Russian space station Mir has been under construction since 1986. It had an expected lifetime of 7 years, but at the end of that time only 4 of the 6 modules had been assembled in space. During its first 7 years in orbit, only 19 man-years of activity were accumulated.(7)
A new international space station proposal is now underway (7a). In 1996, the designers are confidently predicting completion in June 2002, a lifetime of 10 years, and a through life cost of over $100 billion. If it comes to fruition, and that on past experience is doubtful, it will be entirely a non-military venture. The costs are so great that it has to be an international venture, and this precludes military activity.
The real question is whether the presence of men is of such vital importance that it outweighs the cost of the associated support systems. Whether systems are launched from Earth, or assembled in orbit on a space station, they still require the same overall expenditure of energy to put them into orbit. A space station requires the additional energy costs of raising its own support service elements into orbit. The costs benefits, as opposed to the prestige benefits are not obvious, and the balance of cost advantage between manned and unmanned space systems shows little sign of changing in the future.
The second class of satellites to be considered are those used for communications. Here military and civilian development has gone on in parallel. Indeed to the man in the street, communication satellites have been the prime area of progress through the exploitation of space. Worldwide telephone, television and data transmission are now ordinary aspects of modern life. Development work continues in order to provide more powerful television relays from orbit to cover larger areas of the world. In the military sphere, satellites have brought into reality the ability to communicate securely over any distance with total reliability. The vagaries of the ionosphere, which used to make HF communications such a black art, have been replaced by a worldwide communication capability as clear and dependable as line-of-sight VHF radio.(8)
Such communications can transform military effectiveness, but also carry penalties. The ease with which command and control can be exercised from the highest to the lowest formation through satellite based communications makes the military ever more dependent on them. The old back-up methods of HF radio, landline, and runner become even less reliable through lack of use. Yet in the future, satellite communications could be a very productive area for offensive action. The effect of EMP has already been discussed, and more selective anti-satellite measures will be considered later. The disruption of satellite communication links are an important part of any future information warfare plan. Nevertheless, research in both civil and military sectors will lead to more powerful satellite relay facilities which will continue to reduce the size of the communication equipment required on the ground.
Satellite navigation systems have been in operation since 1960. The early systems were based on single satellites in well defined orbits using Doppler frequency shift techniques. Two passes of the satellite were required and the signal needed to be processed by cumbersome ground equipment. Accuracies to within a metre were obtainable within a few days of collecting data. This was of limited utility, and in the mid 1970s the US Department of Defense began development of a system designed to give three dimensional position information, anywhere on the earth, instantaneously and to accuracies of better than one metre. The principle to be used was relatively simple: a number of satellites would send out ranging information, and position would be established by a form of triangulation. Each satellite would transmit a radio pulse at a known time. The receiving unit would calculate how long the signal had taken to arrive and its distance from each satellite. Using four satellites, it is no longer necessary for the receiver to have a synchronised clock. Using a technique developed by radio astronomers in the 1950s, it also proved possible to transmit continuously from all satellites on the same frequency. Pseudo-random sequences were used to encode and differentiate the signals. This Global Positioning System (GPS) began deployment in the early 1980s, and today has some 21 primary satellites with three spares in orbit. (9)
The system of encoding GPS signals appeared to have another advantage for military use. Selective availability could be incorporated. Friendly military forces could use the data with full accuracy and civilian (or potentially hostile forces) could be provided with degraded accuracy. However, civilian scientists rapidly showed how they could work around such selective availability and achieve accuracies to within millimetres using the degraded signals. GPS data has proved so useful to such a range of civilian activities that commercial concerns now broadcast correction data which makes achievement of GPS accuracies to within one centimetre easy to obtain. In the Gulf War, the Allied forces were often issued with civilian differential GPS as it was cheaper, more available and just as accurate as the military encoded GPS units. Another military technology had been exploited for civilian purposes and improved. The Gulf War of 1992 was the first war in which land forces could know their exact position at all times. It allowed co-ordination in a quite new way. Future operations can assume that every individual will know where he is and how to get to where he is going.
There are however significant dangers from universally available GPS. Precise navigation of men or missiles becomes very cheap. Signal degrading does not work, and in any case the Russian GLONASS system provides an alternative method. As civil airlines become more dependent on the system, it will become impossible to turn the system off, and it will be given greater redundancy. Spoofing of the signals will be an important area for research.
Satellites for meteorology and geodetic survey also have military implications. They can provide data for strategic missiles, terrain mapping data for cruise missiles, or tactical weather information for the battlefield commander. The quantity of data which can be obtained, when coupled to the increasingly powerful computers, offers more accurate, detailed, and longer term forecasting. The availability of either type of satellite in war is unlikely to be critical.
Given the importance of satellites to military operations, it is perhaps surprising that there has not been more investment in anti-satellite (ASAT) warfare. As discussed above, the new capabilities brought by satellite systems are making armed forces increasingly dependent and hence vulnerable. A productive area for research is to seek ways to destroy satellites. Such offensive systems may be ground-based, air launched or space-based. ASAT may be widespread in effect, localised or selective against particular systems. Systems that have been looked include an ASAT missile launched by a high flying aircraft (US), and a manoeuvrable exploding satellite (USSR). Possible developments include the use of appropriate frequency laser damage weapons to blind reconnaissance systems. The exploding satellite could be developed into a space mine system, or a missile could expel shrapnel to cause mechanical damage. Should a manned space station be built, then selective ASAT weapons could be used. Directed energy and kinetic energy kill mechanism would both be useful techniques in space. The impetus for research into ASAT systems has declined following the end of the Cold War. Nevertheless, as the major powers become ever more dependent on their space based systems, the potential threat posed by ASAT weapons needs to be kept in mind.
The other part of the ASAT question is development of defensive measures. This is a much more difficult problem. Blacking out sensors under attack is one avenue. Mobility and offensive firepower on otherwise passive satellites may be another. Indeed the future of ASAT warfare begins to sound like the development of air warfare. Its major difference is in the cost of such systems. It may be that ultimately the only defence against pre-emptive satellite destruction is to ensure that military forces do not become totally dependent on the systems. Certainly the advantage of control of space is such that it could be war winning. It appears therefore that ASAT research is a major requirement for defence funding. Some place their hopes in arms control negotiations outlawing such research or deployment. The argument is that it is in the interests of both of the superpowers to be able to have assured use of satellite system for strategic reconnaissance and communication. The world is a safer place when both know that the other can detect and react to a surprise attack; and hence no such attack takes place. The fallacy in this argument is that such a treaty is practically unenforceable. The technologies have many applications and can be rapidly adapted for ASAT work.(10) It is therefore important that both realise that the destruction of one state's satellites by the other will earn retribution in kind. This means that ASAT research is a vital area.
The use of weapons in space for the limited purpose of denying an enemy the use of his satellite systems brings us to the wider consideration of war in space. Since 1983, when President Reagan first looked to scientists to provide protection against strategic nuclear weapons, the possibility of defending against ballistic missiles has kept war in space as a topical issue. The initial research undertaken sought to provide a system which could destroy nuclear ballistic missiles in flight. Research was directed towards providing a layered system. In such a system, missiles would be attacked during their initial launch period when the hot exhaust gases of the rocket motor, and the relatively slower speeds, make them easier targets. During this period response times must be very short (the boost phase lasts only 2-5 minutes). Those that got through this defence would then be attacked during the ballistic mid-course period when the independent warheads separate from the missile. Here there are problems with acquisition, decoys and kill assessment. Finally those missiles penetrating the second layer would have to be destroyed by a final defensive screen designed to destroy warheads re-entering the atmosphere.
The strategic arguments over the utility of such a defensive system were less than straightforward. (11). While the technical arguments about kinetic energy and directed energy weapon feasibility will take years to answer, all agree on the high cost of all systems involved. Figures approaching $1000 billion are suggested as an order of magnitude for deploying a space based defensive system. The system must have target surveillance and acquisition systems, discrimination against decoys, pointing and tracking systems, kill assessment capability, appropriate weapons, and an overall command and control arrangement. All of these require new developments in technology, and can ultimately only provide a limited defence against nuclear weapons. Assuming the highly unlikely possibility that a space-based defensive system worked first time (no real test would ever be possible) and eliminated most ballistic missiles, that would still leave the prospect of nuclear attack by cruise missiles, aircraft and man-carried systems.
The end of the Cold War has reduced the impetus to produce a comprehensive space-based defensive system, and research into SDI continues at a much lower, and more appropriate level. The use of Scud mobile short range conventional surface to surface missiles during the Gulf War of 1992 generated urgent interest in theatre missile defensive systems. It was clear that ten year's of spending on the vastly expensive SDI project had produced nothing of use against this problem. Nor is it likely that future theatre missile defences will be space-based.
Given that nations may nevertheless continue development of space-based defensive systems, some research to counter the systems will remain important. Fortunately the counter systems are by and large both cheaper and less complex. Defence against directed energy weapons through materials technology will pay dividends. The reduction of boost phase time for missiles, and the improvement of decoy systems will also prove fruitful. However the solution to a partially capable missile defence system may be simply to increase the number of offensive missiles. While this does little to help arms control and disarmament, it may be an appealing answer to states in the future.
Moving from defensive to offensive weapons in space, the field is wide open. It is argued that some of the SDI technologies could have offensive possibilities. In the past schemes for orbiting nuclear weapons were considered. Fortunately common-sense has prevailed. While they might offer slightly shorter response times to anywhere on the planet, they would be destabilising and also potentially hazardous both on launch and recovery. The exotic directed energy weapons designed for counter-missile use might have applications against aircraft or cruise missiles. The atmosphere provides considerable protection, and the countermeasures could do much to reduce effectiveness. Conventional missiles could be fired from space-based launchers; but the energy bill to put them in orbit must still be paid, and the advantages are difficult to see.
One kinetic energy system which is under development is the electromagnetic rail gun. In this a small projectile is accelerated to speeds of 5-25 km/sec. The power requirements for such a system are likely to be prohibitive, but it is possible to envisage it having a greater application than just anti-missile operations in space. If the acceleration takes place from orbit, then speed reduction when fired into the atmosphere will be minimal. The problem then becomes one of burn-up. As a system against high flying aircraft it may have application, but again at a cost which is likely to be prohibitive.
Nowhere more than in space technology does the excitement and glamour of research over-ride the mundane considerations of military cost effectiveness. The history of the space age carries all the necessary warnings: progress has been slow and costly. Following the US Space Shuttle disaster, and a series of unmanned launcher failures, the US has found it difficult even to keep up with its routine satellite launch requirements. The Ariane 5 explosion of 1996 showed that cheap and predictable launch systems are still some way away. Grandiose schemes in space all have to answer the question of the energy costs in placing a given mass into orbit. High power weapons call for higher energy cost. In only one area does it appear that research and development could have significant security implications; and that is ASAT. The ability to destroy, disable or disrupt satellites may become a crucial factor. Suitable defensive measures will need to be developed.
NOTES ON CHAPTER 8
1. 'Space: the military applications today and tomorrow' by T.Garden in RUSI & Brassey's Defence Yearbook 1985 pp149 -161.
2. '21st-Century Spacecraft' by F.J.Dyson in Scientific American Sep 95 p 88.
3. The Guardian "And it wasn't insured" 5 June 1996.
4. Dyson ibid p 90.
5.'Advances in antisubmarine warfare' by J S Wit in Scientific American February 1981 pp27-37.
6. 'Space Science, Space Technology and the Space Station' by J A Van Allen in Scientific American January 1986 p29.
7. The Mir Space Station ASEB WWW June 1996
7a.Science in the Sky by T.Beardsley Scientific American June 1996 pp 36-42
8. 'The Development of Command, Control, Communications and Intelligence Systems' by M. van der Veen, in The Militarisation of Space edited by S. Kirby and G Robson, Wheatsheaf 1987, pp13-19.
9. 'The Global Positioning System' by T.A.Herring in Scientific American Feb 96 pp 32-38.
10. The difficulties are well described in Space Weapons and International Security edited by B Jasani (Sipri 1987)pp36-45
11. A good collection of the various views on SDI is found in The Strategic Defense Debate edited by C Snyder (Philadelphia 1986).