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THE FUTURE OF FLIGHT: COMES THE REVOLUTION

Excerpted from The Future of Flight, by Dr. Leik Myrabo and Dr. Dean Ing 

 

 

All futures are not created equally.

Of course, all of those futures are educated guesses. Guessers who assume that all long-established trends must continue will, with Thomas Malthus, often show us gloomy futures; evolution with a vengeance. Yet we know that trends are not always continuous.

The extinction of most dinosaurs, about 64,000,000 years ago, was a natural revolution on Earth; a sudden discontinuity in a very long-established trend. Evidence is mounting that a sizeable asteroid struck this planet with such violence that the ecological carpet was suddenly jerked from under the feet of the great reptiles. Early mammals benefited from this sudden change and a different future evolved. The human race is a beneficiary.

Occasionally a new idea rekindles the human spirit, reverses trends, and creates real changes in the quality of life. When the change is discontinuous, a sharp break from predictable step-by-step evolution, we have revolution. It may be political and violent, or it may be technological and peaceful.

The future we "create" in these pages has an unfair advantage over some others because ours plugs in the revolutionary stuff. We think that is proper because, when people's backs are against the wall, they turn to any revolutionary help that's handy. As it happens, much of our world is nearing disaster in its energy needs—and we are not finding permanent peaceful solutions in conventional ways. Some leaders are beginning to look hard for revolutionary solutions (in several senses!). We're in luck because, among others we will describe, there is one that left the realm of "pure" science fiction around 1960 and it does not require violence or a new government. But it may cause a few governments to evolve in useful ways.

Revolutionary change is relatively rare. It's also less predictable than the weather, which explains why leaders often greet it with gritted teeth. The best they can do is rush to see how the new revolutionary change might affect them because, after the revolution, evolution takes over again, and that's more predictable.

Thanks in part to outrageous claims by advertising flacks, we have just about wrung all the juice from the word revolutionary. Every new kitchen gadget, diet fad and teaching aid is a candidate for the tag, despite the fact that almost all of them evolve, step by painstaking step, from previous ideas without much discontinuity. The marvelous airships of Alberto Santos-Dumont are often mislabeled this way.

Santos-Dumont, an eccentric little Brazilian, became the toast of Europe in the 1890s with his dirigible (which means directable, or steerable) balloons. As a boy, he had read the science fiction of Jules Verne to his saturation point, tinkered with engines on his father's coffee plantation, and built toy hot-air balloons of the type pioneered by the Montgolfiers a century earlier. Arriving in Paris in 1891, he found that cigarshaped balloons had already been tried; hydrogen and other gases were used to inflate some craft, and one Henri Giffard had tried driving balloons with a steam engine. The young Brazilian suspected that existing gasoline engines might be better.

Santos-Dumont saw the high-tech hardware evolving, and put it together with care and courage. By 1899, after gradual improvements, he was putt-putting over Paris rooftops, steering his little dirigibles where he liked. The Zeppelins and blimps of a later day owed much to the daring and gadgeteering of this tiny aeronaut. His autobiography reveals how he proceeded with detail improvements until, years before the Wright Brothers succeeded at Kitty Hawk, Alberto Santos-Dumont could circle the Eiffel Tower. He won worldwide renown, and deserved it; but his work was not revolutionary.

We cite the case of Santos-Dumont to show the steady march of evolutionary design, and to applaud it. But the future of flight involves something more: truly revolutionary discoveries, technologies that are discontinuous from earlier work where Santos-Dumont's was not.

Now we take a case that is revolutionary, even though its discovery was predicted in Santos-Dumont's day. The Russian futurist, Konstantin Tsiolkovsky, wrote during the early years of this century that " . . . energy may even be supplied to a missile, from the Earth, in the form of radiation of one or another wavelength. . . . This source of energy is very attractive to contemplate, but we know little of its possibilities." Of course, there's a huge gulf between predicting something, and demonstrating that it works. Tsiolkovsky risked his reputation by predicting revolutionary changes, with only the sketchiest notion how those changes might be achieved. Many scientists of his time dismissed him as a candidate for a strait-jacket.

Then Albert Einstein, in 1917, wrote a paper on stimulating radiation. On the cover of one issue of Gernsback's Wonder Stories in 1932, science fiction fans saw a propulsion beam; but no one had any firm ideas how power might be beamed without tremendous losses in the beamspread. (Every time the area of the beam doubles, its intensity must drop by half.) During the 1930's at least one man, the inventor Nikola Tesla, pursued his dream of wireless transmission of power.

Tesla proved himself a genius in his early years with Edison but later became secretive and scornful of criticism. We know that Tesla sought to beam power, but we must suspect that he never succeeded.

But by 1954, experimenters managed to amplify microwaves through a scheme they called "Microwave Amplification by Stimulated Emission of Radiation." They soon reduced this jawbreaking phrase to its initial letters: "maser." Then one of the discoverers, Charles Townes, co-wrote a paper suggesting that the scheme should also work for radiation of visible frequencies: an "optical maser." This created a lot of excitement in laboratories, as scientists worked to demonstrate light amplification by stimulating emission of radiation. Of course they soon adopted the short term: "laser."

The first laser was fired by Theodore Maiman of Hughes Aircraft, using a ruby crystal and a flash tube to jolt the crystal with a great wallop of energy. Within a few months, Ali Javan of Bell Labs succeeded using gases instead of rubies.

Both approaches drew instant attention. The amplified beam of light did not spread out like a flashlight beam or even a searchlight. A beam of light as thin as a pencil could be sent for long distances without fanning out much, and had obvious uses such as optical alignment and communication devices. The beam transmitted very low power, but it did transmit a tight beam of wireless power that could be collected by a distant lens. The race was on to develop lasers for special uses—especially lasers of higher power. The revolution had begun.

The Soviets claim that in 1962, Askaryan and Moroz were first to draw attention to the fact that a laser, when vaporizing part of a target, can produce thrust. But researchers credit the U.S.'s Arthur Kantrowitz with the first serious suggestion, in 1971, that lasers might furnish enough power to boost vehicles into orbit. Both in print and in an annual AIAA (American Institute of Aeronautics and Astronautics) meeting, Kantrowitz pointed to the fast-rising power levels of lasers. He suggested that launches to space could be made enormously cheaper by this revolutionary use of beamed power. The AERL scientist added that we were letting naive pessimism put false limits on our future. Always the cautious optimist, Kantrowitz said it might be possible to increase the power of lasers by perhaps six orders of magnitude. 

A multiple of ten is only one order of magnitude; six orders of magnitude increase meant that a laser transmitting, say, ten watts in 1971 might be the forerunner of million-watt lasers one day. History is proving him right, perhaps sooner than he thought. Thanks to stepped-up activity in several related fields—some of it provoked by the redoubtable Kantrowitz—we are now developing lasers measured in megawatts of power output. We see no reason why we cannot keep boosting their power to the gigawatt range. Ten billion watts, furnished for a few minutes' duration, could boost a payload half that of NASA's shuttle from launch pad to orbit at the cost of thirty thousand dollars' worth of electricity. In other words, we could put a payload into orbit for a dollar per pound, instead of nearly a thousand dollars per pound!

Maybe this kind of optimism has a domino effect. In any case, a few scientists began to look around for other ways, in addition to lasers, that we might power vehicles of the future. By now they've come up with several schemes that may rival lasers in the future of flight.

Well then: why aren't we rushing to do it? There are several answers, some of them political. The point to remember is that while the remaining hurdles are real, none of them appear to be basic. This future of flight is a future we can all share. On the other hand, by a general failure of vision or determination, Americans may share a flightless future while others soar above us.

Alan Lovelace, Deputy Administrator of NASA, described part of the problem, and the promise, in 1979. Writing in Astronautics and Aeronautics he said, in part, "Let me sketch for you two possible world `options.' One I will call a fully flight-integrated society. In it everything and everyone flies—not just 65% of the U.S. population, but 100% of the world population. . . . Wherever a person finds himself, there will be a landing site, and he can call for this transportation easier than you can call a cab. . . .

"The other possible world I will call a flight-regressive society, a society that has found no affordable solution to the problems of energy, noise, and pollution, a society in which aviation reverts to the status of a technology too expensive to use. . . .

"The major issue is one of national will. . . . The Wright Brothers did not stick with the bicycle, and I do not think we will either."

Lovelace, in so many words, was calling for a renewal of what historian Joseph Corn calls the "winged gospel." From the early Wright flyers to shortly after World War II, the U.S. raised the dream of flight to something beyond a cult; we viewed flight almost as a religion. We lionized Doolittle, Lindbergh, Earhart, and Halliburton. We doted on our aircraft such as the JN-4 "Jenny," the workhorse DC-3, the advanced little Ercoupe, and strange hybrids like Kellett's autogyro. And if we loved aircraft like those in which we might actually hope to fly, we virtually worshipped the B-29 "Superfortress," the twin-tailed F-38 "Lightning," and the Bell X-l, with the shape of a winged artillery shell, that hangs today in the Smithsonian like a giant's toy. Very few people born after 1945 share the gut-level excitement of their elders whenever a restored P-51 streaks overhead, its in-line Allison snarling a challenge that raises hackles on the old-timer's neck, and perhaps a catch in his throat. Oh yes; we knew a winged gospel in the first half of this century. . . .

Then, somewhere between the German V-2 and the Soviet Sputnik, most of us discarded that fervor. Some have never replaced it with anything. Others replaced it with dreams of wealth, or prowess in sports. True, a few parishioners kept the faith with tiny single-seat air racers or model aircraft. Of those, a very few went on to design hang-gliders and then, like Santos-Dumont, evolved new craft which we call ultralights.

Just as Martin Luther once stirred the world with his new wrinkles on an old religion, the ultralights have produced a storm of controversy among followers of the winged gospel. By now it is becoming clear that ultralights will fill an important niche in the future of flight. Perhaps more important, they have inspired another, more advanced type of new aircraft; the aircraft recreational vehicle, or ARV. That is not to say that everybody likes them yet.

* * *

But a latter-day gospel of flight is growing now, and Princeton's Gerard O'Neill is one of its prophets. When Tsiolkovsky predicted manmade worldlets in space, growing their own food, his contemporaries considered him a mad Russian. When Robert Heinlein wrote of a huge spacecraft with a complete ecological system in his 1941 story "Universe"—well, everybody knew science fiction people were a little strange.

O'Neill, however, is a professor of physics at a prestigious university. Since 1969, with the vital help of young scientists who share the dream, he has been working out the problems of living in space. Not just taking brief visits from our planet, but living and working there, in habitats that provide all of Earth's benefits without some of its drawbacks. O'Neill and his colleagues have shown that most hurdles on the way to space habitats have already been cleared; our primary lack now is the will to do it, because it will be very expensive at first. And faced with huge deficits here on Earth, many people ask: why do anything that expensive?

Answer: for the same reason Queen Isabella hocked her jewels for Columbus. Spain was repaid ten thousandfold in riches from the new world, and the countries that create new worldlets in our solar system will reap wealth so tremendous as to make all that Spanish gold look like pocket change.

Soviets know those details as well as we do. Does the word "cosmograd" ring a bell? It's a Russian word meaning "space city," and cosmograds are a Soviet goal. Stefan Possony, an often-quoted scholar of the Hoover Institute, tells us that the Soviets are expanding their space capabilities well beyond anything needed to support their current military or civilian work. A moon settlement and a huge space station, says Possony, are among the few things that would explain all this furious activity by the USSR; and they have already told us they intend to build such things. James Oberg of NASA, author of Red Star in Orbit, tells us that all this Soviet activity may include a manned Mars mission.

Everyone knows that the Soviets have serious economic problems. They would not be outspending us in the effort to build space cities unless they expected huge returns. They proceed as if they had memorized the books of American engineers like Stine and Pournelle, who are telling everyone who will listen that the wealth is out there, and that it's up for grabs.

A growing fraction of Americans is already impatient to get on with it, to spread the latter-day gospel of flight. The L5 Society is an organization of people working toward permanent settlements beyond the Earth, and toward commerce plying between Earth and those settlements. Anyone can join; its monthly L5 News repays the dues handsomely, and its articles are written for ease of understanding. Its board chairman is Arthur Kantrowitz and its officials include world-famous scientists, publishers, legislators, and futurist writers. A careful reading of the L5 News shows that members are at odds over the support of military space funding. One side of the issue claims that the U.S. should fund only nonmilitary space efforts. The other side replies that space has already been weaponized by the Soviets, and that the U.S. will reap huge peaceful benefits from military space programs—particularly those that are genuinely defensive, not offensive. [For more on this topic, see Mutual Assured Survival by Drs. J. E. Pournelle and Dean Ing, Baen Books, Nov. 1984.—Ed.]

What does "L5" mean? The mathematician Lagrange noted that, in the case of two celestial bodies positioned as the Earth and its moon are, there are five points nearby where much smaller bodies can be stationed where they will stay in position, perhaps oscillating slightly around that "libration" point. Some of those points (such as the gravitational midpoint between Earth and the moon) are not very stable; we might have to keep nudging a satellite to keep it there. But libration points L4 and L5, in the same path as the moon but 60deg. ahead and behind it in Earth orbit, are very stable. Even if we snagged an asteroid a hundred miles thick and placed it at the L5 position, it would stay there, influenced by the gravitational pulls of Earth and the moon.

The L5 Society expects commonplace flight to worldlets in such positions; they say that once you escape Earth, in terms of energy you are halfway to anywhere. Mining the asteroids and colonizing Mars will be fairly straightforward tasks then. Cheap nonpolluting power beamed to Earth from orbit will be a cinch because we already know that structural metals and solar cell chemicals can be extracted from moon dirt—which is known formally as "lunar regolith," and informally as "green cheese," by the way.

O'Neill and his colleagues have developed working models of a device called a "mass driver," a sort of electric catapult which could fling materials up from the moon into lunar orbit. The mass driver is much more efficient in vacuum; though it probably will not be used to hurl payloads up from the Earth, it may be just the thing to boost materials up against the moon's gravity.

Prophets of future flight back their claims with convincing figures, though some claims seem a bit farfetched at first blush. How can we solve earthly pollution from space? By making fossil fuels obsolete, collecting solar power beyond our atmosphere where it is eight times more available and beaming it down to us. How can it help solve overpopulation? By creating so many off-Earth colonies and with flight so cheap that within a century, emigration might well stabilize Earth's population. How will we get there? Several ways, beginning with the present chemical fuels while we develop HEL (High Energy Laser) propulsion systems and some others even more advanced.

* * *

Carl Sagan, testifying before a U.S. Congressional subcommittee, has said that the engineering aspects of space cities seem perfectly worked out by study groups. He added, "It is practical."

Still, it will be tremendously expensive until we develop those cheap, clean propulsion systems. Some systems will boost huge payloads to orbit, while others will power the family flivver to Athens for dinner and back to Topeka afterward. Much of the revolutionary work has already been done; now we need to evolve them in practice. That will take more funding of advanced designs.

Astronaut Gordon Cooper, never one to mince words, summed up the situation in conversation last year with one of the present authors. "In the field of propulsion systems," he said, "most of the scientific establishment is about fifty years behind a few little groups of geniuses. I think we should reassess the whole funding process."

 

MILLENNIAL POSTSCRIPT

For same years, until recent legislation was passed that limits the liability of light aircraft manufacturers, we seemed to be in a flight-regressive society. Thanks (no thanks!) in large part to ambulance-chasers, we've become so litigious that Cessna, Piper, and other manufacturers simply quit building airplanes for the masses. Cessnas are rolling off the assembly line again but meanwhile, devotees of flight began in greater numbers to build planes from plans and kits. Single place puddle-jumpers, six-passenger speed burners, helicopters, powered chutes: the gospel of flight is healthy again. Not only do some of these vehicles look like what James Bond flew, some of them are in those films. If you're interested, contact the Experimental Aircraft Association, Box 3086, Oshkosh, WI 54903.

The space cities I mentioned seem much more likely since Clementine and now the Lunar Prospector, in lunar orbit at this writing, have found evidence of water ice at both poles of our moon. It's not a certainty but the LP spectrometers have mapped what seems to be ice under a foot or so of dry lunar regolith in permanently shadowed regions of both lunar poles How much ice? Not much as moons go, maybe six billion tons, but a thundering lot as human needs go for breathing oxygen, drinking water, and rocket fuel. Once we land nearby, we can mine it with a shovel. Every drop we dig up is one we won't have to bring from home. For more, check Science magazine, 4 September 1998. The cover shows maps.

And getting there may be cheaper than we think, because my coauthor for the previous piece, Dr. Leik Myrabo, is now boosting subscale payloads with high-energy lasers—just as he promised, and pretty much on schedule. Remember, with laserboost you don't have to carry as much propellant and the vehicle can be much cheaper. That revolution we mentioned? It's on the way.

 

 

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