The USSR and space power plants

The American idea of a Solar Power Satellite was proposed for the first time in 1968 by Peter Glaser in a famous article in Science. This concept has since been the subject of many theoretical studies, and of some limited practical studies (mainly about microwave energy transmission) in the USA with funding from NASA and the Department of Energy (DOE). Some evaluations have been also conducted in Western Europe, particularly within the European Space Agency (ESA). But very little is generally known about the attitude towards SPS of the second main space power: the USSR. Soviet literature on SPS is much less abundant, but it does exist. Very interesting articles on the subject have been written by leading Soviet space experts. Some of these articles are analysed here, and the practical meanings of the expressed opinions, generally very favourable, are investigated in view of the growing Soviet space capability.

One of the most positive Soviet com- ments on Solar Power Satellites (SPS) can be found in a book 1 by Professor Konstantin Feoktistov, who is remem- bered as the first engineer to fly in space, but who is also one of the principal designers of the Soviet man- ned spacecrafts. Feoktistov considers that: 'When enough long-duration manned flights have been conducted aboard space stations, much larger objects will have to be erected on Earth orbits. One possibility will be the building of giant solar electric stations to provide energy to Earth's consumers.' Addressing the economic competiveness of SPS, he estimates that 'the cost of these power satellites will be about 2000-3000 rubles/kW, which makes them 1.5-2 times more expensive than atomic power plants', but that due to the fact that SPS do not use natural resources, 'their exploita- tion will become competitive after 5-7 years of operation'. Feoktistov consid- ers that the launching of SPS compo- nents implies the development of heavy-lift vehicles, with a payload of about 500 tons in low-Earth orbit (LEO), and that it will take three to five years to build one SPS. On-orbit building will be done mainly automati- cally, but with some human involve- ment, and 'extravehicular activities conducted within the Salyut program- me confirm the effectiveness of direct human part icipation in assembly works'. The conclusion of Feoktistov is strongly supportive of SPS. 'Cal- culations show that in the future cos- mic electric stations could provide a

substantial contribution to Earth's energy consumption . . . . Their crea- tion is one of the most promising ways for cosmic technology to contribute heavily to the well-being of all human- ity, and to become a highly profitable economic activity.'

A more technical paper 2 has been devoted to the subject of 'Energy and the cosmos' by five Soviet specialists. Among them is Academician V. Avduevsky, who is generally consi- dered one of the leaders of the Soviet drive towards space industrialization. The authors of this article are mainly concerned about the danger of 'ther- mal pollution', which is the emission into the environment of unused ther- mal energy by power or industrial plants, and which could lead to adverse climatic changes. They con- sider that: 'One of the radical ways of avoiding this problem would b e . . . to displace in space an important part of power plants, and of energy consum- ing or dangerous industries'. Their analysis of the 'most economic [energy source] in the present time, which is the breeder', is very interesting when one considers that it was conducted five years before the Chernobyl accident: 'Nuclear reactors produce large quan- tities of potentially dangerous radio- active substances, and they use ura- nium and thorium, the resources of which are limited.'

Avduevsky and his co-authors are thus very interested in solar cosmic electricity stations, which they con- sider to be comparable, in terms of economic potential effectiveness, to

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future thermonuclear (fusion) reac- tors. They estimate that: 'Even today, there are enough serious reasons to look at [SPS] as one of the most promising energy sources.' However they estimate that the 'Glaser project' is not realistic if it assumes, as now, the use of chemical launchers and of very heavy SPS (mass on the order of 50-80 000 tons for a 10 GW station). Their opinion is that the rational solution to the problem of space elec- tricity use on Earth will require:

(1) a radically new idea for rocket propulsion between Earth and near space (transportation be- tween LEO and geostationary orbit then using electric pro- pulsion),

(2) new ideas to reduce considerably SPS mass for a given energy output.

Avduevsky and his co-authors con- sider that laser technology could be used to solve these two problems. They contemplate the use of laser propulsion to thrust rockets from Earth to LEO (a powerful laser beam focused from Earth on the rocket is used to heat a propellant which is ejected at a very high speed). The system they describe is a very large- scale one: a 100 GW laser provides a total energy output of 1014; (assuming a 10% efficiency) to a rocket with a liftoff weight of 200 tons and a payload of 100 tons; the propellant is water, and the ejection speed is 20 km per second. The electrical energy is pro- vided by the SPS themselves and s tored before use in a super- conducting system; the total mass of the installations on Earth would be more than 100 million tons, and the cost of the system would be higher than US $40 million.

For reducing SPS system mass, in space and on Earth, the Soviet special- ists consider the use of direct conver- sion of solar light into laser energy directly transmitted towards very effi- cient (70%) photonic conversion sys- tems on Earth. They also look at the possibility of using thermonuclear energy in place of solar energy in cosmic power stations: their opinion is that a 10 GW space thermonuclear plant, with transmission of energy to

SPACE POLICY November 1986 361

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Earth by laser beams, would weigh only 20-30 000 tons, that is much less than an SPS. The interest of placing fusion nuclear reactors in space would be to relieve Earth of thermal pollu- tion (heat which is not converted into electricity, which could be two-thirds of the total energy generated, is emit- ted into space, and not into the terrestrial environment).

Avduevsky and his co-authors con- sider a very optimistic schedule for space power plants: 'First experiments connected with transmission of energy from space towards Earth could be conducted in principle during the next 10-15 years. It would be then possible to establish experimental cosmic elec- tricity stations, and during the first decades of the next century such stations could provide an important part of humanity's energy consump- tion.'

This optimistic projection is no different from that of another Soviet specialist on space power systems, S. Khouliakov, 3 who writes: 'In the opin- ion of many scientists, SPS technolo- gies could be developed during the 1990-2000 period, and beginning in 2010-2020, two 5-GW SPS could be built yearly. ' (It is not clear, however, whe ther Khou l i akov ' s p ro jec t ion comes from a Soviet analysis, like Avduevsky's, or if it only reflects US projects.

There are, however, some dissent- ing views. Soviet scientist Leonid Leskov 4 considers, for instance, that: 'Designs of a full-scale network of space-based power stations, which are being put forward at present, cannot be regarded as realistic.' But this

opinion does not prevent him from proposing a phased approach to SPS: 'At first the capacity of a station will reach 1000 kW. [This] will make it possible to verify many methodologic- al problems of the space-based power industry and to test the main units.'

All of these statements show that Soviet specialists are at least in princi- ple very much interested in space- based power plants. Does that mean that they are on the verge of embark- ing on a large-scale programme? It is true that the USSR is conducting the largest space programme in the world, at least by the number of annual launches (about 100) and by the total mass put each year in low-Earth orbit (about 700 tons). 5 These capabilities will probably grow significantly over the next years, with the appearance of the long-awaited Soviet heavy-lift launcher, able to inject more than 100 tons into LEO, and later able to place in orbit a large space plane about the size of the orbiter of the US Shuttle. It is true also that the USSR is running into many problems with fossil energy resources and with nuclear power util ization, which could lead the Soviet leadership to be interested in establishing the feasibility of alterna- tive energy sources such as SPS. Soviet specialists could thus by the 1990s have both the capabilities and the political support to conduct space experiments on some SPS technol- ogies. The MIR modular space sta- tion, and its larger follow-on antici- pated in a few years, would be the right place to conduct these experi- ments.

However, even if such experiments

take place, the USSR would still be a very long way from full-scale tests of experimental SPS, and still further from development of such stations. Their transportation system will be insufficient by one or two orders of magnitude, and would probably stay much too costly, due to the use of chemical propellants. It will perhaps be decades before the appearance of new, much more powerful Soviet launchers, reusable and/or using very advanced technologies. Before pre- dicting any rapid initiatives in space by the USSR, it is important to remem- ber that the USSR has a history of very careful and very progressive ad- vances in space.

This being so, it is nevertheless certain that the USSR has a strong commitment to space industrializa- tion, and a declared interest in cosmic electricity power plants. The first real space experiments on SPS techno- logies could thus be conducted on Soviet space stations in the near fu- ture.

Dr Alain Dupas CNES

Paris, France 1Konstantin Feoktistov, O Kosmoletakh, Molodaia Guardia publishing house, Mos- cow, 1982. 2V. Avduevsky, C. Grichin, L. Leskov, V. Ablekov and A. Evitch, 'Energetika i Kos- mos', Zemlia i Vselennaia, June 1981. 3S. Khouliakov, Kocmitcheckie energo- ousta-novski, Novoe v jiznL naouke, tekh- nike, seria kosmonavtika i astronomia, Znanie publishing house, July 1984. 4Leonid Leskov, 'Power-industry orbital complexes of the 21st century', Space Policy, February 1985. 5Alain Dupas, 'Le Programme spatial Sovietique', La Recherche, November 1984.

362 S P A C E POL ICY November 1986