Power—industry orbital complexes of the 21st century

Reports

Power-industry orbital complexes of the 21 st century Soviet scientist, Leonid Leskov, discusses the state of the art and future projections of the Soviet and global industrialization of space. International cooperation for peaceful use of space are required if the huge benefits of industrialization, such as solar power stations, are to be realized. The past few years have witnessed the rapid development of a new trend in the use of outer space by man space industrialization. According to modern concepts such industrialization presupposes the solution of a range of interconnected problems. Work in some of these areas is underway, and at present appropriate space systems are effective enough both technologically and economically. This is especially true of space c o m m u n i c a t i o n systems, satellite meteorology and space photography. Other trends are in the development stage, the majority of them being the production of semiconductor materials, metals, alloys and biomedical preparations aboard space vehicles. Their performance is better than that of samples manufactured on the Earth. Finally some trends of space industrialization are now in the research and design stage - space-based solar power stations for the supply of the Earth with electric power, the industrialization of the Moon, the illumination of various areas of the Earth by orbital reflectors etc.

Industrial production in space At Soviet Salyut 5, Salyut 6 and Salyut 7 orbital stations and during the launchings of high-altitude rockets of the Mir-2 complex several hundred experiments have been carried out in manufacturing semiconductor materials, metals, alloys, glass-like media, and biomedical preparations. In many cases the structure of samples has been better than that of prototypes made on the Earth. At the same time, the experiments have shown that there are some unexpected effects, and that processes at zero gravity have proved to be more complex than it seemed initially. This

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has led to the necessity of laying down scientific foundations of space-based production. The amount of accumulated knowledge has proved to be sufficient to start preparations for the experimental industrial manufacture of some materials, whilst continuing with the research. Production aboard spacecraft can be highly efficient. For instance, according to some estimates, the prod u c t i o n of s e m i c o n d u c t o r and electronic-optical materials can give a profit of up to US$200 million/year. If the purified culture of umkinase (an enzyme produced in a human organism which can dissolve thrombi) is obtained artificially aboard space vehicles, medics will possess an effective method of combating infarctions and other cardiovascular diseases. The transfer to the full-scale commercial production of materials in outer space will require onboard power installations of up to 25-100 kW and special self-contained technological modules. Such modules can fly at some distance from a basic orbital station which will house a laboratory for proximate analysis of samples and a system for controlling the powerindustry complex. Cosmonauts will regularly leave the basic station for modules to repair equipment and replace samples there.

Solar power stations In 1968 US engineer Peter (}laser proposed to supply the Earth with power by space-based solar stations. His paper at the International Astronautical Congress stimulated research in this area all over the world. In fact, both concepts on which Glaser's project is based - the idea of solar power stations for the supply of the Earth with power and the use of focused microwave radiation for the transmis-

sion of power from outer space to ti~Earth - may be traced to the ideas ~{ S o v i e t s c i e n t i s t s : the work ~,i Academician Valentin (ilushk,) ~f~ 1929, of Professor (;corg 3 Bab:l~ it: 1948, and of cnginccr Nikolai \' irva~ov in 1960. The following principle is the basis of all designs of space solm powcz stations. Structures arc installed on ~ geostationary orbit removed from the Earth's surface by 36 (100 kin. The main element of these slruclnre'-, iS ~ system of transforming sohn- radiation into microwaxc radiation transmitted to Earth. A photoelectric transducer is usually regarded as a solar powcr receiver. On the Earth, micro'~avc radiation is trapped by a rccciving aerial, is transformed into the clectric current of required parameters and transferred to the t,scr. A c c o r d i n g to design estimates space-based solar power stations will be giant space structures. The electric power of such a station will anlourlt to 10 million kW. the area of solal cells will reach l(lO km e and lnass 50 (100 IC, 100 0(/0 tons. Thc receiving aerial will occupy several hundreds of kin:. The operation of these space giants does not require the consumption of natural power resources and ,aill not affect the cnvinnnncnt in any majot way: hardly any microwave radiation is absorbed in the atmosphere, and the efficiency of its transformation into the electric current is over 9()gl

Projections to 2020 Some experts I~clieve that during the first decades of thc 21st century such stations will already be the main pov,er source for the Earth. tIowcver, this opinion is subiect to serious objections. What arc the actual possibilities of implementing this idea, proceeding from the task of meeting about 2(/% of world p o w er r e q u i r e m e n t s from space-based solar stations by the year 202(i)? If the implementation of such a programme is started before the year 2000, it will be necessary to place into a near-Earth orbit about 2 - 5.10 > tons of cargoes every week. Let us assume that new carrier rockets of enormous carrying capacities will be created - up

SPACE POLICY February 1985

Reports to 500 tons with the specific cost of $20/kilogram. (This value is roughly 100 times lower than in the case of the Space Shuttle reusable transport system.) It will be necessary to launch such carrier rockets every 20 minutes, and expenditure on their launching alone will amount to about $600 000 million a year. Besides, the regular launching of super-heavy carrier rockets will annually introduce up to 5-108 tons of combustion products of rocket fuel into the atmosphere. In other words, designs of a full-scale network of space-based power stations, which are being put forward at present, cannot be regarded as realistic. There are proposals to begin the industrialization of circumterrestrial space with the industrial use of the Moon. But these large-scale designs should be regarded today as unfeasible too.

Creating the global system The development of the global system of orbital objects is of a comprehensive character and, step by step, solves the problems of the industrial uses of outer space. It controls the placement of space vehicles in geostationary, solar-synchronous and other orbits. The global system of orbital objects can be used for tackling some interconnected problems - the establishment of a space multipurpose power base, the improvement of the illumination of some areas on the Earth, an increase in the productivity of ground-based power stations using the energy of solar radiation etc. In establishing a space power basis it is supposed to use many designs of space solar power stations, but the approach should be of a phased character. For instance, at first the capacity of a station will reach 1 000 kW. Such a station will make it possible to verify many methodological problems of the space-based power industry and to test the main units. For instance, a team of Soviet researchers has recently shown that the use of amorphous silicon, applied on a flexible film base, for promising photoelectric transducers, reduces the specific mass of solar power stations up to 3.5 kg/kW. A further rise in the

S P A C E P O L I C Y February 1985

efficiency of photoelectric transducers use extra heat for obtaining hydrogen. is possible. The success and the scale of imAnother promising direction is the plementing this programme will dedesigning of onboard thermonuclear pend on the design of carrier rockets reactors. Orbital power plants of a and space transport power plants. sufficiently high capacity will be used According to the estimate of Dr Kond u r i n g the c r e a t i o n of p o w e r - stantin Feoktistov, pilot-cosmonaut of producing space complexes, for the the USSR, in the future it will be transmission of power to other space feasible to create super-heavy carrier vehicles etc. rockets which will deliver to a referIt is important to improve the illu- ence circumterrestrial orbit a payload mination of some areas on the Earth, of 500 tons with specific cost of about eg, high-latitude industrial zones over $165/kg. Further off in the future, the the winter period, agricultural areas at design of reusable carrier rockets, night, in the harvesting season etc. To provided with air-breathing jet ensolve most of these problems it is gines, could lead to the reduction of enough to have an illumination level specific cost by a factor of ten. of about 10 luxes or about 100 full As optimum space engines for the moons. According to some estimates transportation of cargoes from a referto obtain such illumination on an area ence low-Earth orbit to other orbits, it of about 90 000 km 2 it is necessary to is most rational to use electrical rocket use a reflector with an area of several engines which were tested for the first km 2, the mass of the reflector being time at the Soviet Zond-2 space stanot more than 1 000 tons. tion in 1964 and which have repeatedCalculations show that the use of ly been used in outer space since then. the system of reflectors with an overall Highly efficient engines of this type area of 200 to 1 000 km 2 will make it engines with an anode layer - have possible to intensify considerably the been designed in the USSR. production of cereals in middle latiThe industrialization of outer space tudes on an area of up to 10 million for peaceful purposes calls for huge hectares. investments. That is why the fulfilPlacing a system of reflectors with ment of such programmes can become an overall area of 1 000 km 2 in an a reality only under the conditions of orbit 1 600 km high, it is possible to durable peace on our planet. illuminate an area of about 200 km 2 on the Earth's surface at the level of full Leonid Leskov sun. Even with the use of modern USSR photoelectric transducers this can ensure an electric capacity of up to 20 This article is published by permission of million kW. Besides, it is rational to the Novosti Press Agency.

The challenge of the US space station We are on the verge of a new era of commercial and industrial expansion in space that will have a major impact on America's future and on the future of the world. It is a turning point that will set the US national agenda in space we//into the 21st century, and, as such, will have an important impact on space-related activities worldwide. The USA is now gearing up to face the challenges of this new era. James Beggs, NASA Administrator, describes the US space station programme.

While space transportation may once have been a spectator sport, it is now a game with high stakes involving many players. There are the carriers, the

users - scientific, commercial and industrial - and the manufacturers. In the remaining 15 years of this century, space will be an expanding

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