Toward Distant Suns
by T. A. Heppenheimer
Copyright 1979, 2007 by T. A. Heppenheimer, reproduced with permission
Chapter 3: Space Colonization Soon?
We may say that astronautics is the science of dreams, and in the early 1950s that science was already some fifty years old. The general public had long since been made aware of the existence of large rockets, such as the German V-2 of World War II, and looked to the development of even larger rockets for the then widely anticipated World War III. Rocket aircraft, flights to the Moon, exploration of Mars and of other planets—had all been widely discussed in the popular press. Science fiction was booming, and such movies as Destination Moon and The Conquest of Space were playing to large crowds. The public was primed.
So it was, in such an atmosphere, that the rocket scientist Wernher von Braun set forth a vision for the future. He proposed that the nation commit its energies and resources to a project that he said could be built with current technology: a space station. The cost was to be a mere $4 billion in 1952 dollars, some $15 billion in today's money.
Von Braun proposed to build and develop a fleet of huge three-stage reusable shuttle rockets, 265 feet tall and weighing 7,000 tons—more than twice the weight of the Saturn V moon rocket. Each rocket was to lift on the thrust of fifty-one rocket motors, generating a total thrust of 14,000 tons, compared with 3,750 tons for the Saturn V. The third stage would be a piloted, delta-wing craft, somewhat resembling today 's space shuttle orbiter, carrying 36 tons of cargo to orbit 1,075 miles up.
The cargo would consist of elements for the space station proper, which would be a wheel-shaped affair, closely resembling the one made famous in the movie 2001: A Space Odyssey. It would house two hundred crew members; even at that early date, Von Braun argued that the crew should include both sexes. The station was to be 250 feet across with three decks or levels and rotating to provide one-third normal gravity. Its proponents suggested that such a station could carry atom-armed missiles and telescopes to peer down on the Kremlin, but as von Braun made clear in his book The Mars Project, the real purpose of such a space station would be to support a manned flight to Mars.
The feasibility of such a project can best be judged by examining the performance records of the day. The most advanced rocket airplane was the Douglas Skyrocket. In 1951 it touched 1,238 miles per hour at 79,000 feet—rather higher but a bit slower than the cruise conditions of today's commercial Concorde jets. The most advanced made-in-USA rocket was the Viking. When it worked properly, which was never a foregone conclusion, it would lift off with ten tons of thrust and reach an altitude of 135 miles. It did not inject a satellite into orbit at that height, but simply made an up-and-down flight like an arrow shot into the air. Eventually, with further development, Viking served as the first stage of Vanguard, which launched satellites into low orbits having the magnificent weight of fifty pounds.
Even today, a project such as von Braun's would represent no mean feat. In the 1950s it was widely publicized in magazines and TV shows and generated much attention among science-fiction fans. More serious rocket specialists were inclined to dismiss it as at best a dream for the distant future, at worst a hopeless fantasy. And yet it could not be ignored, for von Braun was the world's foremost and most experienced rocket designer.
This bit of history is worth remembering when contemplating the colonization of space. The idea of space colonies traces back to the earliest space pioneer, Konstantin Tsiolkovsky. Most of the important concepts can be found in the writings of Krafft Ehricke, Arthur C. Clarke, and particularly Dandridge Cole, whose 1964 book, Islands in Space, was entirely devoted to the topic. Since 1974, Gerard K. O'Neill, professor of physics at Princeton University, has led the modern studies of the subject. It is O'Neill who has organized the Princeton technical meetings beginning in 1974, as well as the study programs at NASA's Ames Research Center, which have brought space colonies to the serious attention of both the public and the aerospace industry.
The most significant of these studies took place in the summer of 1975 and provided much of the subject matter for my earlier book, Colonies in Space. The final study report was regarded as so important that it was published by the Government Printing Office as a hardcover book, with a foreword written by the head of NASA, James G. Fletcher. Although many details have been revised, the basic outline of space colonization presented there remains the accepted one to this day.
This view of a space colony called for an orbiting city, as far removed from an Apollo capsule or space shuttle flight deck as is a California seacoast town from a cave. The people would live in garden apartments with two or three bedrooms, surrounded by blooms of color. There would be flowers and lush gardens, parks and fruit trees, ivy and lawns—and, not to be outdone, the apartments themselves would sport stuccoed walls and tinted window panels.
Inside would be drapes, carpets, comfortable furniture, all imported from Earth or, so far as possible, built from aluminum and other metals taken from the Moon. There would be no cars (everything would be within walking distance), and sophisticated air-conditioning equipment would remove pollution while keeping temperatures comfortable. The sky would always be blue. Nor would the people lack for recreation, for the availability of zero-g would offer new possibilities. The colonists themselves would live in normal gravity, though, for their colony would rotate.
The colony itself, the Stanford torus, was conceived as a rotating wheel with six spokes and has a startling resemblance to von Braun's space station. It would be much larger, however: a mile across, providing a home for 10,000 people. Half the colony interior would be used for agriculture; the other half would serve as living space, divided into three communities, each with its own spoke. Living conditions then would be no more crowded than in some of the small European walled towns that date to the Middle Ages.
Again there would be a fleet of rockets to build it—the Flyback F-1. The first stage would be a winged version of the Saturn V first stage and would use the same engines. The second, cargo-carrying stage would be developed from elements of the space shuttle. Each such cargo rocket would carry two hundred tons to orbit at a shipping cost of twenty-five dollars per pound. Alternately, the payload compartment would be fitted out as a wide-body spaceliner, carrying two hundred passengers. For flight beyond low orbit, there would be a deep-space rocket, again developed from space shuttle hardware, capable of landing one thousand tons on the moon.
What would go to the Moon would be a lunar mining and transport facility. A crew of some one hundred moon-miners would be sent to scoop up lunar soil, package it in forty-pound bags, and then launch these bags into space using a mass-driver, or electromagnetic catapult. There in space, a large conical mass-catcher would serve to catch the bags, filling up at the rate of one hundred thousand tons per month. Once a month, a full load would be delivered to the colony.
Initially, of course, there would be no colony, but rather a "construction shack" equipped with processing and manufacturing facilities. Staffed with two thousand workers, and initially built in low Earth orbit, it would be moved to the colony site in deep space. There it would receive the loads of raw lunar material from the mass-catcher and process them into fabricated metal: aluminum, iron, magnesium, titanium. There would be oxygen, too, produced in huge quantities. Slag left over from the processing would serve to build a shield against cosmic radiation.
The function of the colonists would be to build solar power satellites: immense structures, miles in length and width, to convert sunlight to electricity and beam the electricity to Earth using focused beams of microwaves. At the ground these beams would be received and reconverted, each powersat providing enough electricity for New York City. In this manner, the existence of space colonies would help solve the energy crisis.
Such have been the dreams of those who would colonize space—imaginative and far-reaching, firmly grounded in present-day science and engineering, yet withal quite wistful and romantic. And how will these dreams look a quarter-century from now? Will the ten-thousand-person space community seem less naive, less unrealistic than von Braun's proposal to use two hundred astronauts to accomplish the military tasks that today are done entirely by automated equipment? Will the idea of space agriculture be seen as reflecting any real understanding of the actual problems in supporting a community of space workers?
We cannot answer these questions without an understanding of today's space programs and research and of the history of technology. The science of astronautics is older than most people think; it is arresting to realize that the first serious work in the field was contemporaneous with the Spanish-American War. It has seen recurrent waves of enthusiasm for various projects, the dreams of its visionaries. Time and again, its acolytes have come forth with enthusiastic speculations, offered confidently as predictions for the future. Time and again, these projects have failed to elicit the demonstrated practicality that would bring them to reality. Yet, astronautics has advanced.
The history of aviation provides a useful model for the future of astronautics. At the turn of the century, aviation was a risky and marginal activity of a few enthusiasts, having rather the same role in the nation as hang gliding today. (The technologies of the two activities are quite similar.) Today, tens of millions of people pass each year through such major airports as JFK and O'Hare, while such once-impregnable institutions as the passenger railroad and steamship have long since been relegated to nostalgic supplements to a transportation industry dominated by aircraft. Thirty years ago, the departure of such liners as the Queen Mary or Ile de France was an Event; today, the Boeing 747 carries its hundreds of passengers at twenty times the speed, and its departure is noted chiefly by the air-traffic controllers.
None of this happened because of dramatic presidential decisions or of nationwide crash programs in response to foreign challenges. The key people who planned and carried out aviation's growth did not regard themselves as agents of destiny nor were they self-consciously driven by a sense of mission. The first flights of such revolutionary aircraft as the 707 (the "Dash-80") and DC-3 in no way were attended by the media coverage and ticker-tape parades that accompanied the first flights of astronauts in Project Mercury. Aviation's progress was the work of canny managers and corporate executives seeking business opportunity and the result of many small advances, few of which were in themselves revolutionary. Indeed, on the one occasion when commercial aviation indulged in a self-conscious sense of mission or destiny, the result was that magnificent economic flop—the SST.
Aviation is not the only activity offering instructive historical lessons to those who would colonize space. Over a century ago, the Age of Steam saw developments that appear today to be almost eerily parallel to the Apollo program. These events involved the building of the first large iron ships.
The sea has always been deeply conservative in its practice; innovations have traditionally been regarded with suspicion, as likely to fail and to cost the lives of sailors. The introduction of steam brought no sudden change in ships, either in their size or appearance. Well into the twentieth century, steamers continued to carry sail-bearing yards on their mainmasts. Far more so than in aviation, the development of modern navies and merchant marines was slow, gradual, deliberate, with change being all but imperceptible from year to year.
The advent of steam propulsion in the mid-nineteenth century stimulated the dreams of visionaries and attracted the talents of brilliant engineers, just as would the advent of rocket propulsion a century later. Foremost among these designers was one who may be regarded as the Wernher von Braun of his day—the Englishman Isambard Kingdom Brunel.
The son of Sir Marc Brunel, builder of the first tunnel beneath the Thames, Brunel distinguished himself early as chief engineer of Britain's Great Western Railway. When that railroad company expanded into shipbuilding in 1836, Brunel was chosen to design its steamship, the Great Western. It was of wood and was propelled by paddle wheels; at 1,320 gross tons, it was the largest steamer then afloat. It was the first ship to demonstrate the feasibility of operating a transatlantic passenger liner under steam.
His second ship, the Great Britain (1843), also broke new ground. Her capacity, 3,270 gross tons, made her the first large ship to be built of iron. Brunel invented the structural design used in her construction and built her so strongly that, even in 1970, her hull still could be salvaged from Sparrow Cove in the Falkland Islands and removed to permanent exhibition in Bristol, England. A commercial success, Great Britain convinced shipbuilding experts of the superiority of iron hulls for large ships.
These two ships came at roughly the same time in Brunel's career as did the V-2 and Jupiter-C rockets in von Braun's, and had the same impact on the shipbuilding world as did von Braun's projects in the world of rocketry. The V-2 of 1944 proved the feasibility of building large liquid-fueled rockets. The Jupiter-C of 1956 launched America's first satellite in 1958 and convinced critics of the desirability of using tested existing rockets whenever possible.
Von Braun's third pathbreaking project was Apollo. Brunei's was the Great Eastern. Apollo's principal rocket, the Saturn V, was an astonishing five times larger than the earlier Saturn I; and Great Eastern was five times larger than Great Britain. At 18,915 gross tons, with a length of 680 feet, Great Eastern represented a size that even today would be eminently respectable. In her day (she was launched in 1858) she was a leap decades ahead into the future.
Brunel built her expecting to exploit economies of scale. She could carry four thousand passengers and six thousand tons of cargo; she could run around the world, via Capes Horn and Good Hope, with only one refueling stop. He expected his ship would monopolize the sea route to India and Australia, but few shipowners shared his enthusiasm. During her construction, Brunel sought the advice of an expert friend: "If she belonged to you, in what trade would you place her?" The reply was direct: "Send her to Brighton, dig out a hole in the beach and bed her stern in it. . . . She would make a substantial pier . . . her old magnificent saltwater baths and her 'tween decks a grand hotel. . . . I do not know any other trade, at present, in which she would likely pay so well."
Brunel ignored this advice and placed her in service. It soon was obvious that the cargoes he sought for her could not be found; the world of the 1860s had little demand for her immense capacity. She saw limited use on the North Atlantic run as a troopship to safeguard British interests in Canada during the U. S. Civil War. For a few years she was chartered to lay undersea cables, linking England and America by telegraph in 1866. By 1874 the advent of special cable-laying ships forced her out of that business, and she was laid up in port. Finally, in 1888 Great Eastern went to the breaker's yard. Not till 1899 did a larger ship, White Star Line's Oceanic, enter service. By then, advances in marine engineering had long since rendered Great Eastern obsolete.
It is impossible to resist noting the parallels to Apollo. The Saturn V and its Apollo spacecraft were built, not merely to go to the Moon, but to open up space to large-scale use. Yet the Saturn V failed to bring forth the cargoes or space traffic that could fill her huge capacity: 140 tons to orbit. By 1970 its production line was scheduled to be shut down, and the remaining craft were soon sent for display in museums. Attention shifted to the space shuttle, with advanced design features as well as a cargo capacity (32 tons) better suited to the traffic anticipated for the 1980s.
Yet while it took decades of time, that magnificent failure, the Great Eastern, indeed was succeeded by the successful Oceanic. And by the centennial of Great Eastern, 1958, the shipping world had long grown accustomed to far larger ships. Similarly, one may surely anticipate that in the decades to come, growing space traffic will compel anew the building of rockets with Apollo-size cargoes, and with larger cargoes still, but incorporating advanced designs, which will make the Saturn V entirely obsolete.
And if astronautics is to grow in this fashion—if a slow, patient advance will bit by bit increase the scope and tempo of space flight—then in time it will become entirely reasonable to undertake activities to challenge the imagination of space pioneers. Such activities will have their own pace and logic, and may no more resemble the classic dreams of space flight than today's cruise ships resemble Brunel's dream of a cheap, high-density passage to India. For all that, these space programs will be as startling, in comparison to the space world of 1979, as is JFK Airport in comparison to the aviation of the 1920s.
What may these programs be, and how may they come about?
In answering this, it is necessary to be cautious. The best sources of information come from the aerospace industry 's studies and projections done by key people under contract. But such sources must be weighed and assessed with great care, for the aerospace industry is notorious for its self-serving tendencies. Charles Wilson, secretary of defense in the Eisenhower administration, once gained fame for allegedly remarking that "what's good for General Motors is good for the country"; in the aerospace industry, this spirit is alive and well. [Author's footnote: The correct quote: "I have always said that what's good for the country is good for General Motors, and vice versa."
Thus, aerospace spokesmen have frequently justified space expenditures on the ground that they lead to spin-offs. A spin-off is a product or process useful in the nonaerospace economy, which was first developed or invented to support the space program. Such a spin-off is the Pillsbury food stick (originally marketed as Space Food Sticks), first developed by Pillsbury under NASA contract as a food for astronauts. A more substantive example of a legitimate spin-off is the Boeing 747. In 1965 Boeing and Lockheed competed to win an Air Force contract to build a large military transport aircraft, the C-5. Lockheed won the contract, but Boeing, not to be outdone, modified its design for the civilian market and put it into production as the 747.
Boeing's jet nevertheless was a spin-off from Air Force work. An often-cited spin-off from NASA research is the familiar Teflon-lined frying pan. Teflon, it has been said over and over again, resulted from NASA work; ergo, NASA deserves more money, the better to create more such wonders. In fact, though, Teflon was first developed by the Air Force. It was introduced about 1955 to reduce friction in the engines of some of their propeller-driven aircraft. A few years later Teflon served to line the large molds in which were cast the charges of solid propellant used in the Minuteman missile. Neither application had any bearing on the space program.
To be fair, there are legitimate spin-offs from NASA work that have use in such areas as medicine and fireproofing. But it could hardly be otherwise. It is difficult to see how the nation could spend billions on space projects without producing at least some spin-offs. In the main, though, space system requirements have been too uniquely specialized to produce inventions having any obvious use outside the space program.
During the heyday of the Apollo program, its contractors regularly invoked more than mere spin-offs as justification for the project. Their spokesmen often claimed that the lunar landing would produce a major scientific benefit: an understanding of how the world began. They expected to find that the Moon was composed of primordial, unaltered material, dating to the earliest days of the Solar System. In fact, however, it was early found that the material of the Moon had been melted, separated, and drastically altered early in its history to nearly the same degree as the rocks of Earth. So far from learning the origin of the Solar System, the Apollo flights failed to give even a firm indication of the origin of the Moon.
The industry response to this contretemps, predictably, was to call for more Apollo flights. The search was on for a "genesis rock," a truly primordial artifact, which might lie just beyond the next crater. This went on till the last Apollo flight, Apollo 17, in 1972. By then, Apollo-funded experimenters were turning in outstanding scientific work, but each Apollo flight was costing $400 million. The entire 1973 budget for the National Science Foundation, which supports most U. S. basic science, was $480 million. Measured against the priorities of the whole of basic research, the search for lunar genesis rocks simply could not compete. In any case, nonlunar genesis rocks could be found already, in museums. Certain meteorites, known as carbonaceous chondrites, indeed are truly primordial. The Allende meteorite, mentioned earlier, is an example.
The first Apollo landing was in 1969. Paradoxically, that year in fact did see a major advance in our understanding of the origin of the Solar System; but it had nothing to do with Apollo. It came in the form of a disarmingly slim book of mathematics, written in the Soviet Union by V. S. Safranov and published in the West under the title, Evolution of the Protoplanetary Cloud and the Origin of the Earth and Planets. It described the work of the Soviet school of planetary scientists, whose work in many respects surpassed that of Western investigators. Since then, that book has served as the point of departure for much of the best work on planet formation; its methods and approaches are regarded as entirely essential in modern studies of that problem. But such studies do not require flights to the Moon. They rarely require flights to the next state, unless a scientific conference is being held there.
It is essential to keep a skeptical attitude toward the claims of the aerospace industry. If indeed a space project is to go forward, the expertise of the industry is essential, but in light of the number of projects possible the key question is whether a particular project indeed should advance. It is in this skeptical spirit that one must also approach the statements that space colonization is inevitable, or that major increases in space activity lie on the horizon. Yet to those who advocate space colonization, such skepticism can be not a bad thing but an advantage. A skeptical approach will give full weight to difficulties, will recognize alternative approaches, and will emphasize an understanding of how large projects really come into being. If space colonization fails these tests, if it falls apart at the first serious attempt at criticism, then it is better discovered now than later. But if, despite such challenges, space colonization truly is found to be plausible and reasonable, then one can have high confidence that in time it will come about.
It is in this spirit that one may search for a reason to spark a vastly larger space program. A popular choice has been space industrialization: the building of factories in space to produce important new products by taking advantage of zero-g. Some advocates have claimed that this would usher in a "third industrial revolution, " producing major changes across the entire range of modern technology. A study by Science Applications, Inc. has suggested that such activities could spawn a $6 billion per year manufacturing industry within the next quarter-century. Milan Bier, a leading specialist in biophysics, has gone further and suggested that a potential market of this size exists for just one type of space manufacturing alone—the purification of pharmaceuticals used in medicine.
Such pharmaceuticals would include a variety of extremely powerful hormones recently discovered through research on the brain. The most important of these are super-hormones, which do not directly control body processes but which regulate the production of other hormones that do. These super-hormones include LHRF (luteinizing hormone releasing factor), which regulates production of fertility hormones. There is also somatostasin, which regulates the action of the pituitary gland, controller of human growth. It is these brain hormones, which transmit the instructions or commands that shape the features of a life: "Keep warm," "Reproduce," "Grow no more."
Other important brain hormones are the enkephalins and endorphins. These are, to use Karl Marx's phrase, the opiates of the masses: morphine-like substances naturally found in the brain. Enkephalins serve in transmitting impulses along nerve pathways. The function of endorphins is not well understood, but it is believed that they aid in influencing the functioning of the pituitary. The study of these hormones has already led to major advances in fundamental understanding of the way pain-killers work, as well as the cause of drug addiction. Further work in this area is expected to bring not only better pain-killers, but also a cure for drug addiction.
Such hormones are very powerful; doses in the millionths of a gram would be typical. Yet their production would also be quite costly, in the tens of thousands of dollars per gram. Thus, if space processing would ease their production, the cost of the necessary space factories could readily be accepted. Such factories would rely on the production process known as electrophoresis, and it has been frequently claimed that the zero-g conditions of space would greatly enhance the usefulness of this process.
Electrophoresis is a powerful means for separating out the different components of a mixture of biochemicals. In this technique, electric charges are placed on the molecules of the mixture within a container filled with fluid. An electric field is set up across the fluid, causing the individual molecules to migrate across. Differences in the sizes or shapes of the molecules lead to differences in their rates of migration, so that a desired type of molecule can be separated out and purified even if it is present in minute concentrations. But the electrophoretic process is quite sensitive and easily upset by convection currents in the fluid. In zero-g such convection currents are absent. Hence some investigators have predicted that the size of electrophoretic apparatus could be greatly enlarged in space, leading to production rates thirty to one hundred times greater than on Earth.
Another possible product for a space factory is the large, highly uniform crystals of semiconductors, which are the basis for the modern electronics industry. It has been claimed that the absence of gravity would allow the growing of such crystals with greater purity and uniformity, greater freedom from imperfections, and larger size. Such crystals, in turn, might permit manufacture of improved solid-state devices. To support these ideas, advocates of space processing have made use of the results of crystal-growing experiments conducted aboard Skylab. In these experiments, space-grown crystals indeed were superior to crystals grown in similar experiments on Earth.
The prospects for space manufacturing were reviewed in 1978 by a committee of the National Academy of Sciences, the nation's foremost scientific body. The director of the review was William P. Slichter, executive director for materials science at Bell Laboratories. The general tone of their report was not at all favorable to the idea of space factories. To the contrary, their report again and again suggested the well-tried patience of specialist experts who had heard too many enthusiastic claims from people who didn't know what they were talking about. On the general idea of a program to develop space manufacturing operations, they wrote in "Materials Processing in Space":
On electrophoresis in space:
On improved materials for electronics:
On the whole idea of space factories, their conclusion was unequivocal:
Why should this be? The people who advocate space processing or space manufacturing are not wild-eyed incompetents nor are they fools; to the contrary, they are sober and serious experts in their fields. The problem is that their field usually is aerospace engineering, which is not quite the same thing as pharmacology or materials science or solid-state electronics. Therefore, the scope of the aerospace engineer is limited to possibilities in space, whereas the pharmacologist or electronics expert may be attuned to alternatives that may be more effective than the space-oriented ones.
In light of this fact, one may look with better hope to those areas in which there already is a long and close partnership between aerospace and its customers. Then the customers come to the engineers to seek aid in new projects. The most outstanding example of such a partnership is the communications satellite. Can space communications lead to a very large space program? The answer is yes. Moreover, it will be nothing new if space communications pace the growth of the space program in the 1980s. It will instead be a continuation of past trends.
There can be no doubt that for all its postponed dreams and budget cuts, the space program has grown in twenty years from a highly dramatic sport for superpowers to an unheralded but highly significant feature of the modern U.S.A. This has happened in part—but only in part—through the Apollo program, one of the few major proposals of the space dreamers to be rendered into hardware. For the most part, the advances have involved small, undramatic steps in observations of weather and earth resources, military reconnaissance, astronomy and other sciences—and communications. As with the growth of aviation or the computer industry, the cumulative sum of many small advances has turned out to be a new and pervasive technology, largely taken for granted, yet influential in the lives of nearly everyone.
While many of the space dreamers wrote of flights to Mars or of space stations, the real advances of astronautics were going forward quietly, foreseen by few. Thus, in his 1957 book Rockets, Missiles, and Space Travel, Willy Ley had mentioned the possibility of placing satellites in what is now known as geosynchronous orbit, 22,300 miles up:
Yet by 1972, fifteen years later, space traffic projections showed 43 percent of all traffic in the 1980s would be heading for geosynch. The advantage of having communications satellites fixed in position was so strong that no alternate orbit would do. Was the orbit difficult to reach? The aerospace industry responded by developing advanced rocket craft, particularly by building improved versions of the well-proved Delta launch vehicle. Today, looking to the 1990s and beyond, the communications industry faces a problem of which Willy Ley never dreamed: an actual saturation of the geosynch orbit, or shortage of desirable satellite locations along its arc.
Such saturation does not mean—at least not yet—that geosynchronous orbit will be as packed with spacecraft as a freeway during rush hour. Instead, it means that the satellites would be so closely spaced as to interfere with each others' operation. As of 1978 there were already some ninety-three spacecraft operating in geosynchronous orbit, or planned for launch. This rather lengthy list merely included the satellites that were planned to be in day-to-day use. It did not include such famous old satellites as Early Bird and Syncom, which pioneered the use of that orbit but which have long since been shut down as obsolete.
Satellites in geosynch are not evenly distributed, but tend to be clustered where they can view areas of heavy communications traffic. Locations over the western U.S., above the Atlantic, or over central Asia are particularly favored. If two such satellites operate at different radio frequencies, they will not interfere with each other no matter how close their locations. But there are only a few standard frequency bands used in communications. If two satellites are using the same frequency band and are closer together than 2° in longitude along the orbit, then there will be interference. Why? Because the radio beam sent up from a ground station spreads out as it rises, so that the ground station would be transmitting to two or more satellites instead of just to one.
So the world's growing needs for satellite communications cannot long be met simply by launching more satellites of existing types. Nor is there doubt that these needs will continue to grow rapidly in the years ahead. In 1978 there were 470 million telephones in the world, of which 165 million were in the U.S.; by the year 2000, the world total may top 2 billion. That year will also see over a billion TV sets in use throughout the world. In this rapid increase in communications traffic, satellite communications will set the pace. The amount of traffic carried by Intelsat, the international satellite communications organization, is expected to double every three and a half years.
The result of this challenge will be the obsolescence of the communications satellite as we have known it: a single compact spacecraft, launched aboard a single rocket and unfolded or deployed in orbit. Instead, there will be the communications platform. The first such platform may be under way as a formal project as early as 1981 and operating by 1986.
Its sheer size will put it in a class by itself. The largest communications satellite orbited to date, ATS-6, featured an antenna 30 feet wide. By contrast, the geosynchronous platform is proposed to be 269 feet by 102 feet in dimensions. It will do the work of many smaller satellites, thus relieving the problem of orbit crowding.
Each such platform will require five flights of the space shuttle. The first two flights will each carry to orbit an external tank, the large propellant tank that carries the shuttle's fuel supply. These tanks will be equipped with small rails and will be joined end to end while in orbit, forming a strong scaffolding on which construction takes place. One of these flights also will carry a twenty-five-kilowatt solar power system, developing more power than the whole array of solar panels used on Skylab. This power system will provide energy for construction of the platform and then serve to operate the platform once it is complete.
The third shuttle flight will carry a crane, to be fitted to the rails of the two-tank scaffold. It will also carry the structural components for the largest single communications antenna, a hundred feet in diameter. During this seven-day flight, astronauts will assemble the antenna and mount it to the scaffold with the aid of the crane.
The fourth shuttle flight will build the main, 18,000-pound platform structure. To do this, it will carry rolls of sheet aluminum as well as standard lengths of aluminum sections resembling angle irons. The shuttle also will carry a beam-builder: an automatic machine that cuts and welds the aluminum to form structural beams, lightweight and strong. The mission should last thirty days, time enough for the crew to form the beams and assemble them using the crane. The crew also will install prepackaged electronics and other, smaller antennas, thus completing the platform proper.
The fifth and last shuttle flight will carry a rocket stage to boost the completed platform to geosynchronous orbit. The boost must be prolonged and very gentle to avoid straining the large, delicate platform with too-rapid motion. Thus, this transfer rocket will be a new design and a fairly major project in itself. This rocket will serve as well in future years, for as communications needs grow, the platform will also grow. Additional shuttle flights, supported by the transfer rocket, will deliver new electronics packages to the geosynchronous platform. There, automated robots—another new system—will install them.
In addition to providing expanded service for present-day communications, such platforms will offer entirely new services. Ivan Bekey, of the Aerospace Corporation (and now of NASA), has pointed out that as communications satellites grow very large, they can also be made very powerful, and able to service millions of ground stations. These stations, in turn, can be quite modest in transmitting power; yet their signal still will be picked up in orbit and rebroadcast. Carried to their logical conclusions, these ideas can give realization to an old fantasy: the Dick Tracy-style wrist radio, or telephone.
The wrist telephone would resemble a modern wristwatch; already some digital wristwatches incorporate the functions of a calculator, and this new service would be easy to add. There would also be a speaker, a small internal antenna, and a battery. Each wrist unit would have its own phone number and would respond with a "beep" when that number was called by signal from the satellite.
Such wrist units would not replace today 's telephones; their tinny-sounding speech and use of a battery would make them suited only for short messages. Yet how often this would prove convenient! How commonly do we go on a trip, or one of our friends goes, and there is no straightforward way to keep in touch. Anyone who wanted to reach a friend would merely signal to his phone number, and if the number was right and he were wearing his wrist unit, he would be located anywhere in the world.
The wrist phones would be most useful for paging: "I miss you; please get to a regular phone, and let's talk." In addition they would be very valuable for people who face danger. A hang-glider pilot might be blown to a remote canyon, but with his wrist phone he could guide rescuers. People who travel a lot, including long-haul truckers, might regard them as better than citizens-band radio. Such services then would offer still more opportunities for large communications platforms.
Such platforms will still fall far short of space colonization, yet will be far more advanced than previous space missions. Moreover, this project will prove out and develop many key techniques that may ultimately serve in the building of true colonies. For the first time, multiple shuttle flights will be needed to assemble a structure in space. For the first time, astronaut work crews will assemble these structures. The beam-builders, the use of a scaffold-mounted crane, the automated robots, and the advanced transfer rocket will be new. Most important of all, these new methods and techniques will not come about through speculation, or merely because key people are very taken with these ideas. They will come about entirely because of growing needs for communication. Their development thus is as inevitable as next month 's phone bill.
Are there other activities, other than communications, that can provide the foundation on which to build an even larger space program? There are, and one of these involves a somewhat unpopular but inescapable matter, the military in space. Fortunately, what is in prospect here is nothing so gross (and, by treaty, illegal) as orbiting nuclear bombs or stationing missiles in space. What is to come instead is the next revolution in weaponry, one which may make the ICBM obsolete. As with communications, a bit of history again is in order. Even before the first A-bomb, writers of science fiction could look ahead to a defense against it. This was the death-ray, a powerful and concentrated beam of energy, easily capable of destroying a bomber or missile. To anyone steeped in Buck Rogers, a prediction in the 1930s of a mass attack by nuclear ICBMs might well have brought the riposte: Why not protect against this science-fiction attack with an equally fictional death-ray defense? No attacking missile would serve any purpose if it could be blown up while in flight, before reaching its target.
The irony is that in the 1930s, such a viewpoint would have been entirely understandable. Years before there was any understanding of how to build a nuclear bomb, physicists in laboratories were already producing beams of protons and of electrons for their experiments. If not quite death-rays these beams nonetheless required careful handling since they were dangerous to life.
In the 1940s, the first atom bombs changed everything. With the development of powerful rockets and guidance systems, the threat of a nuclear-missile exchange emerged from science fiction to become a dominant reality in the world of the fifties and sixties. So destructive were these weapons, so terrifying the disaster that would follow their use, that nothing more than a change in their numbers or patterns of deployment could trigger a major international confrontation. That was what brought the Cuban missile crisis in 1962.
After that crisis, the world settled into a nuclear balance of terror. Neither superpower could restrain the development of improved weapons; neither could achieve any significant advantage over the other. Like a dormant earthquake fault, the nuclear threat was always there—not something to worry over in day-to-day life, yet not something to be dismissed and put out of mind.
Throughout all this, time and again there were people who suggested that the physicists' particle beams could be turned into weapons. The invention of the laser, a source of concentrated light beams, stimulated new thoughts of shooting down bombers or missiles with what would then be a life-ray. Yet none of these weapons proposals were convincing. The energy sources that would power them were inadequate; the beams could not be made powerful. Also there were serious problems of aiming, of detecting targets, and of causing the beam to propagate without spreading out or dissipating. In the early seventies the Navy sought to develop an electron-beam weapon (Project Seesaw). The abandonment of this effort, due to technical difficulties, only strengthened Pentagon reluctance to take seriously the idea of energy-beam weapons.
In the meantime General George Keegan, head of Air Force intelligence, argued forcefully that the Soviets were developing proton-beam weapons as a means of missile defense. The resulting debate was secret, but the implications for American defense potentially were quite strong. Keegan not only argued that intelligence data supported his views; he used Air Force funds to sponsor the research of a group of scientists and intelligence analysts at Wright-Patterson Air Force Base in Ohio. He emphasized his view that this group's findings clearly pointed to the feasibility of beam weapons. However, to the CIA and to the Air Force's scientific advisors, Keegan's views were unconvincing.
The side that lost out in the secret debate was the side that went public. Keegan leaked his intelligence findings to Aviation Week, a widely respected aerospace magazine. In its issue of May 2, 1977, editors Robert Hotz and Clarence Robinson warned that the Soviets had made a key breakthrough and were years ahead of the U.S. in particle-beams weapons research. The administration could not ignore such statements. The CIA issued one of its infrequent official announcements to deny that the nation was in danger. President Carter himself was moved to comment: "We do not see any likelihood at all, based on our constant monitoring of the Soviet Union as best we can, that they have any prospective breakthrough in the new weapons systems that would endanger the security of our country."
Yet in the fall of 1978 in a six-part series of articles in Aviation Week, plans were revealed to set up an Office of Directed Energy Technology in the Defense Department. The Navy would have principal responsibility for electron beams, the Army and Air Force jointly for proton beams, and the Army for beams of neutral or uncharged atoms. The Air Force also would carry forward with development of high-power laser weapons, emitting intense, highly focused beams of light. One could imagine a hydrogen atom marked ARMY with its nucleus (a proton) marked AIR FORCE and its outer electron bearing the legend U.S. NAVY.
The Navy's program was revealed as the most advanced and having the highest priority. Called Chair Heritage, it currently looks toward key experiments in late 1981 or early 1982 to determine whether electron-beam weapons can protect cruisers and aircraft carriers from Soviet cruise missiles. Chair Heritage is being developed first because naval vessels can already provide energy from on-board power supplies to operate particle weapons. Their propulsion turbines develop high levels of power. Also it is easier to defend against cruise missiles than against an ICBM.
The Navy concepts call for individual electron-beam devices to be installed below decks. The beams would be guided by magnets and fired from rotating cylinders. These pulsed beams would make use of key findings in the Chair Heritage program: An electron pulse bores a hole in the air, leaving a trail which is hotter and less dense. Electrons in the next pulse face less resistance as they travel toward the target. However, this hole does not act as a channel. The beam can be moved and will carve a new path to the target. Also, it has a "self-pinching" effect, which keeps it from spreading out.
The Air Force is seeking to develop powerful lasers to protect its reconnaissance spacecraft from Soviet killer satellites. In the past decade the Soviets have conducted at least sixteen antisatellite tests. During ten of them the killer satellite passed within a few thousand feet of its intended target, close enough to ensure a successful kill. An antisatellite laser would fire at the Soviet spacecraft from the ground, blinding its sensors and antennas. With sufficient power, the laser would vaporize part of the satellite structure, causing further damage.
Can such lasers or particle beams be placed aboard orbiting spacecraft? An obvious possibility is the "Trojan powersat": a power satellite that in time of peace would provide electricity to the ground, but that all along would secretly carry beam weapons as armament. Like the Trojan horse of Homer's Iliad, in time of war it would prove a gift of which to beware, for it would easily supply enough power to provide ample defense against an attack on its home nation.
The problems with this are several. Powersats will be so large and flimsy that they will not readily be protected against attack; they could easily be disabled by other beam weapons. In war such armed powersats would prove attractive targets, for whatever their value as producers of energy, they would first have to be destroyed before an attacker could launch his missiles with confidence. More than one nation might build such armed powersats. In time of international crisis, a battle of dueling powersats might knock out much of the world's energy supply.
An armed powersat would actually be a latter-day version of one of the weapons of World War I. At the turn of the century, the pride of Britain and Germany were their fleets of luxurious transatlantic liners. These were advertised as "greyhounds of the sea," but what was not advertised was that they were equipped to carry naval cannon in wartime. The Lusitania, for one, could mount twelve six-inch guns, thus delivering a heavier broadside than the cruisers that guarded the English Channel. When a German submarine sent that ship to the bottom in 1915, the English press fell over itself in denouncing this as a horrible act of barbarism. What was not publicized was that in the 1914 edition of Britain's standard naval reference Jane's Fighting Ships (issued to all German sub commanders), the Lusitania was listed as an armed auxiliary cruiser.
This event demonstrated the futility of arming important civilian ships as vessels of war, and it has not been done since. One hopes that future generals will remember this history and not cast covetous eyes at the powersats. As with the world's navies, specialized spacecraft will be needed.
For defense against ballistic missiles, the Army is pursuing its space-based Sipapu program (an American Indian word meaning "sacred fire"). Sipapu calls for orbiting generators to produce intense beams of neutral hydrogen atoms, which would not spread out in space as would beams of protons or electrons. The Army is also interested in orbiting lasers. Such lasers could deliver concentrated pulses of energy a million times more intense than the concentration of energy from a nuclear bomb. What's more, the laser can deliver its energy in one-millionth the time of a nuclear weapon. Yet the laser is not a weapon of mass destruction, capable of annihilating cities and ports. It is a weapon of discrete destruction. It offers extremely precise control of rather small amounts of total energy, such as the energy of fifty pounds of high explosive, sufficient to destroy an enemy missile. If an ICBM is killed just after launch, it will stop accelerating. Its warhead may land in the home territory of its own nation.
Quoting officials close to the Army's Sipapu and laser programs, Aviation Week (October 16, 1978) had this to report:
If space battle stations are to be built, hardened against attack, they may come to be built from lunar resources. Lunar soil would provide a bulky material for thick, attack-resistant walls. There may be spacecraft resembling the battle star of Star Wars, with immense shells full of lunar materials.
Beyond this, it is unwise to speculate. We are as if we had lived a century ago, trying to imagine the future of World War I. In 1880 war was still regarded as chivalrous and grand, seen in terms of Napoleon and la gloire. Only as recently as 1862 Robert E. Lee had watched the lifting fog at Fredericksburg disclose the massed Union host and had exulted: "It is good that war is so terrible, else we should grow too fond of it." As we look ahead, our parochialism is similar.
The matter of military activities in space is shrouded in secrecy and thus is difficult to assess. The same is not true of what may offer the most important prospects for a really extensive space program. These prospects lie in the area of energy. Indeed, it is possible that we will seriously look to space for a long-term solution to our energy needs. We then would reach into space so extensively that amid our activities, space colonization could come about in an entirely natural way.
The idea of the power satellite began as a speculation, and had it remained so, space colonies today would appear as one speculation founded upon another. However, in recent years the world has changed. Even very speculative energy sources have received new and often serious attention. It thus is appropriate to recall how these changes in the energy picture have come about, and not only give a further description of the powersat, but also to assess its importance.