To be more precise, it's about 60,000 megatons; and if need be, we can use hydrogen bombs. Put an H-bomb at the center of mass of an asteroid and light it off; I guarantee you that sucker will move. It's expensive, but not grossly so, assuming I have laser triggers for my H-bombs; only a few tons of hydrogen.
I could also do it with fusion: at 10% efficiency I get 6.4 x 1017 ergs per gram of hydrogen, and I need about 1027 ergs total to move the rock; for an engine I use an ion engine, breaking up parts of the asteroid for reaction mass. What arrives is something less than I started with, but who cares? What I'll throw away as reaction mass is the slag from my refinery.
(For those who haven't the foggiest notion of what I'm talking about: a rocket works by throwing something overboard. The reaction mass is what's thrown. Although the big space program rockets use gaseous exhaust as reaction mass, there's no reason you couldn't use dust, ground up rock, or slag from a metals refinery. It's all a question of whether you can throw it sternwards fast.)
But that leads to another possibility: why not set up the refinery out at the Belt? Put up vast mirror systems and do the refining on the way in; use the slag as reaction mass to move the whole works, rock, refinery, and all. I can power that with solar mirrors. Or I can do all at once: use bombs for initial impetus, set up mirrors when I'm closer in, and while I'm at it run a hydrogen fusion plant aboard the moving strip-mine/refinery/spaceship I have created.
At worst I have to carry about one Saturn rocket's worth of hydrogen, plus several shiploads of crew and other gear; and for that I get an entire year's worth of metals for the world. The value of my rock is somewhere near a trillion dollars once it's in Earth orbit; more than enough to pay for the space program and pay off the National Debt at the same time.
So. For the price of some hydrogen and a rather complex ship system I've brought home enough metal to give everyone on Earth access to riches. If we do nothing else in space; if we come up with no new and startling processes such as I've described in other columns (and in other chapters of this book)—we'll have licked pollution and dwindling resources, thereby letting the developing countries industrialize, and thereby whipping the food production crisis for a while.
We have avoided the fourth doom. And that's all of them.
* * *
Sure: there's a limit to growth. But with all of space to play with I'll be happy to leave the problem for my descendants of 10,000 years hence to worry about.
I can hear the critics spluttering now. "But-but-but—what does this madman think he's doing? Flinging numbers like that around! Bringing in asteroids. It's absurd!"
Really? Remember, we haul quantities like that around here on Earth even now; in trains, and on boats, and it takes far more energy to process them here than it would in space. To get that energy here we must burn fossil fuels—which are really far too valuable as chemicals to set a match to—and put up with the resulting pollution. And, after all, I've assumed that we're going to supply the whole world with metals at the rate that we produce them from all sources—including recycling—here at ground level US of A. What's so absurd about it?
No, we won't be operating in space on this scale for a few years; but then we weren't producing all those tons of steel in 1930 either. Even the worst crunch models will not kill us off before 2020—a year in which we might very well be able to move asteroids around, boil them up for processing, and bring the resulting metals down for use here on Earth. It's a year in which we certainly will have Solar Power Satellites, always assuming that we want SPS. And there's approximately as much time between now and 1930 as now and 2020.
Yes. We live on a finite Earth. But there's a whole solar system out there. If we like we do not live on "Only One Earth." If we like, we live in a system of nine planets, 36 moons, a million asteroids, a billion comets, and a very large thermonuclear reactor/radiation source. It's all waiting for us out there. We've only to lift our heads out of the muck to find not only survival, but survival with style.
A Blueprint for Survival
This may be a unique century in many ways. In one respect it certainly is: this is the first time that mankind has had the resources to leave Earth and make his home in the solar system. No one doubts that we can do it. It takes only determination and investment.
Alas, we may be unique in another way: ours may be the only century in all of history when Mankind can break free of Earth. Our opportunity may not come again, per omnia seculae seculorum. Thus it could be that we have it in our power to condemn our descendants to imprisonment forever.
After the publication of "Survival with Style," a reader commented as follows: "I remain skeptical. By the time man is forced to accept population control, the world is going to be in a sadder state than it is now. And I doubt if nations will give up their armaments and their free school lunches in order to get the resources to mine the asteroids until the situation is so bad that we probably can't mine the asteroids in time to save us."
Unfortunately he may be right. There are no end of foreseeable crises, and enough of them could so deplete our resource base and technological ability that when we realize that we must go to space, we won't be able to get there. Furthermore, anti-technological sentiments are no joke; a great number of influential intellectuals have embraced Zero-Growth, condemn technology, and seem to want the next generation to atone for the sins of our forefathers. They do not appear to want themselves to atone; I haven't seen many leading intellectuals giving up their own luxuries, much less necessities, in order to make amends for the "rape of the Earth," "eco-doom," and the rest of what engineers and technologists are accused of. We shall continue to enjoy; but after us, The Deluge. Our children shall pay.
And of course if Zero-Growth has its way, our children will pay; but ours won't pay as much as the children of the people in the developing countries. Those kids are doomed with no chance at all.
Do not misunderstand. Were Earth our only source of energy and resources, I should probably myself be crying Doom. As it is, I fully support many conservation measures—and in fact I was writing pro-conservation articles as early as 1957. I've no use for wasters of Earth's bounty. But I've less use for those who would condemn most of the world to eternal poverty when there are ways that we can do something about it.
Incidentally, the Club of Rome, which sponsored the original computer studies leading to THE LIMITS TO GROWTH, and provides much of the intellectual fuel for Zero-Growth, has now sponsored a second report entitled MANKIND AT THE TURNING POINT (MATTP). This book, unlike LIMITS, is supposed to hold out some hope for the poor. By looking at the world as a set of 10 "regions" we can, say the author of MATTP, divide the wealth and sustain what they call "balanced growth."
Unfortunately they never tell us how. As one reviewer put it, "I do not find any clear explanation of the ways in which balancing out the regions of the world would lead to any lessening of the total demands of human civilization on the planet's living-space, resources, and vital ecosystems." (Frank Hopkins, in the October 1975 Futurist.) Moreover, the MATTP plan demands foreign aid at the rate of $500 billion a year at the end of a 50 year development period. True, there are plans with less massive foreign aid investments; but all are truly enormous.
And this is nonsense. No politician is going to run on a platform of international bounty. No democratic—or communist—nation is going to shell out wealth at that rate. And even if, by some miracle, the western nations were to divvy up with everyone else, the Second Report can't challenge one feature of THE LIMITS TO GROWTH: no matter how wildly successful we are in imposing Zero-Growth and population control, in 400 years the game will be over. We will have run out of non-renewable resources. Mankind will have no choice but to give up high-energy civilization and return to some kind of pastoral society.
Surely this is not a desirable goal? There may be those who dream of the simple life (and a lesser number who will actually choose to live it), but surely only a madman would impose it on everyone else
without dire necessity? If there is any alternative, must we not take it?
* * *
There are alternatives. They aren't even very expensive compared to the MATTP plan. Take, for example, the detailed plans of Princeton professor Gerard K. O'Neill.
Details of what have come to be called O'Neill Colonies were first widely published in the September 1974 issue of Physics Today. The plan has been modified somewhat since that time, most recently by a week-long NASA sponsored conference of some of the biggest names in space exploration, but the basic concept remains the same: building self-sustaining colonies in space. O'Neill colonies have a major advantage: they are not only self-sustaining, but will be capable of building more colonies without further investment from Earth. Moreover, they will be able to make some important contributions to Earth's economy.
There's been a great deal of excitement in the science community, and of course among science fiction fans, although oddly enough most SF writers haven't put much about O'Neill colonies into print. I haven't because I assumed others would, and I was waiting for new details. Certainly much of the SF community is aware of the O'Neill concept. "Life In Space" is now a regular program item at science fiction conventions.
The basic O'Neill plan is for colonies able to support from 10 to 50 thousand people each. They will be located in the L4 and L5 points of the Earth-Moon system. Since not all readers will know what that means, and the location is important to the economics of the concept, let me take a moment to explain Trojan Points.
The equations of gravitational attraction are so complex that we can't really predict where planets, satellites, moons, etc., will be after long periods of time. Given high-speed computers we can make approximations, but we can't precisely solve problems involving three or more bodies except in special cases. A long time ago LaGrange discovered one of those special cases, namely? that when a system consists of three objects, one extremely massive with respect to the rest, and a third very small with respect to the other two, there are five points of stability: that is, things that get to those points tend to say there. These are often called "LaGrangian Points," and designated by the numbers LI, L2, . . . L5. They are illustrated in Figure 8.
Of the five, three are not really stable; that is, if an object is perturbed out of LI, L2, or L3, it won't tend to return. The other two, L4 and L5, are dynamically stable, and it takes a special effort to get out of those locations. Left to themselves things put into points L4 and L5 will be there forever.
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Figure 8
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Nothing is left to itself, of course: there are more than three bodies in the solar system. Even so, satellites placed at those points would be stable over geological eras.
Points L4 and L5 are named Trojan Points because in the Sol-Jupiter system these points are occupied by a number of asteroids named after Trojan War heroes. The Trojans trail Jupiter, while the Greeks lead. Unfortunately the custom of naming the Eastern group for Greeks and the Western for Trojans wasn't established before one asteroid in each cluster was named for the wrong class of hero; thus there's a Trojan spy among the Greeks, and vice-versa.
Because of the perturbing influence of other planets, Trojan Points aren't really "points"; the Trojan asteroids drift around within a sausage-shaped area about an AU (93,000,000 miles) in diameter, while objects in the Earth-Moon Trojan Points would tend to drift a few thousand miles one way or another; but they're stable enough for our needs. Colonies, and supplies for the colonies, once arrived at L4 and L5, won't go anywhere. The points are, of course, 240 thousand miles from Earth, and an equal distance from the Moon.
O'Neill colonies will be big. Even the first model, which is intended as an assembly base and factory, will be several kilometers in diameter. Later models will be bigger. One design calls for a cylinder 6 kilometers in diameter and several times that in length. The cylinders slowly rotate to provide artificial gravity. The exact gravity wanted isn't known yet, but it will certainly be less than that of Earth, possibly low enough that man-powered flight (yes, I mean people with artificial wings) will be not only feasible, but the usual means of personal transportation. As O'Neill points out, a great number of energy-consuming activities required for civilized life on Earth won't be needed in the colonies. Roads and automobiles and trucks aren't wanted.
It's possible to wax poetic about the idyllic life in O'Neill colonies, but I won't do that. In the first place I may be far-out technologically, but I don't think people are likely to live in Utopian style no matter how pleasant their environment. The important point is that life can be pleasant, and certainly possible, in space colonies.
These colonies are to be self-sufficient: they have more than enough agricultural space to feed their inhabitants. More importantly, they have a product to sell Earth: energy. It is perfectly feasible to collect solar power, convert that to electricity, and beam the juice down to Earth by microwave. Tests show the cycle, DC to DC, is about 65% efficient—and of course most of the wasted energy doesn't get to Earth, but stays in space. There are a number of designs for the Earth-based receivers. The one I like best is a grid of wires several meters above ground: energy densities are low enough to allow cattle to graze comfortably in the pasture below. Alternatively, you could plant orange groves there.
All this sounds lovely, but surely it's a bit far-fetched? No. O'Neill's designs use present technology. There are no super-strong materials and no magic systems. We could begin building an O'Neill colony this year, occupy it in 1990, and by the year 2000 have a couple more of them built, in which case we could also be supplying about as much power to Earth as the Alaskan pipeline will. In 20 more years space could supply nearly all the US electric power."
So why don't we do it?
It's bloody expensive, that's why. Make no mistake: this would be a costly undertaking, on a level of effort comparable to the Interstate Highway System, or the Viet Nam War.
It would not, in my judgment, be nearly so expensive as Zero-Growth, but unfortunately the costs of space colonies are visible. They're direct expenditures. The costs of Zero-Growth are hidden, since the most costly part is in potential not used and goods not created.
In the December 5, 1975 Science (the prestigious publication of the American Association for the Advancement of Science) Dr. O'Neill presents an economic analysis of satellite solar power stations (SSPS's) and Space Manufacturing Facilities. He comes up with total costs ranging from a low of $31 billion—about the proportion of GNP that Apollo cost—to a high of $185 billion. He also discusses benefits from the electric power produced by SSPS's, and concludes that over a 40 year period the facilities would show actual profits from sales of power alone.
As a co-discoverer (with Poul Anderson) of what was once known in the aerospace industry as Pournelle's Law of Costs and Schedules ("Everything takes longer and costs more"), I tend to distrust Dr. O'Neill's numbers. It hardly makes any difference. The important point is that the program is feasible. We could afford it. Take a worst-case. Suppose it takes 25 years, and the total cost is 50 Apollo programs, that is, a round one trillion bucks. The money must be spent at $40 billion a year for the next 25 years, which comes to $200 a year for every man, woman, and child in the US. In my own family it would be about $1000 a year.
That's a lot of money. Worth it, I think; the benefits are literally incalculable. For example, by the year 2000 the US will need 2 billion tons of coal annually simply to operate our electric power system. Nuclear power plants could reduce that substantially, but the nuclear industry is in deep legal—not technological—trouble. It would be worth a lot to me simply to avoid the strip mines that 2 billion tons a year will require.
Moreover, the space budget isn't going to be simply tacked onto the national budget. All of the money will be spent here on Earth—people living in Lunar and space colonies have no need for Earth dollars, and what they physically import is tiny compared to the salaries that will be paid to Earth workers manufa
cturing products for the colony program. With $40 billion a year in high-technology industries, we can eliminate a number of "pump-priming" expenditures and dismantle several welfare and unemployment compensation schemes as well.
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Figure 9
BE OF GOOD CHEER,
THERE'S HOPE FOR US YET. . . .
O'NEILL COLONIES
Assume each colony can build one new colony in ten years. Assume there are only 50,000 people in each colony. Assume we don't get started until 2020 AD. . .
By 2283 AD (Standing Room Only at 4% population growth),
There will be
3.85 x 1015 people living in O'Neill Colonies.
Comparing favorably to the 6.8 x 1014 people required to cover the Earth. . . .
(WELL, we never said we'd give the Club of Rome a monopoly on exponential curves.)
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Of course we won't really need to spend that kind of money? and I suspect we can start getting returns on that investment before 25 years. O'Neill himself thinks in terms of some $5 billion a year, which works out to $25 a head for each person in the US; and the colonies have got to be worth that if only in entertainment value.
A Step Farther Out Page 4