Prelude to Space

by Arthur C. Clarke

  Dirk winced slightly at the phrase; he felt that rather too many people had been “looking after him.” Collins led him to a small office not far away where they sat down and exchanged cigarettes. After puffing thoughtfully for some time, the aerodynamicist jerked his thumb towards the door and remarked:

  “What do you think of the Chief?”

  “I’m a bit biased, you know; we’re from the same State. He seems a most remarkable man—cultured as well as technically brilliant. It’s not a usual combination. And he’s been very helpful.”

  Collins began to wax enthusiastic.

  “That’s perfectly true. He’s the best chap you could possibly work for, and I don’t think he has a single enemy. That’s quite a contrast to Sir Robert, who has dozens among people who know him only slightly.”

  “I’ve met the Director-General only once. I didn’t know quite what to make of him.”

  Collins laughed.

  “It takes a long time to get used to the D.-G.—he certainly hasn’t Professor Maxton’s easy charm. If you do a job badly, the D.G. will burn your ears off while the Prof, will give you a hurt look that makes you feel like a professional baby-poisoner. Both techniques work perfectly, and everyone’s very fond of Sir Robert when they get to know him.”

  Dirk examined the room with more than casual interest. It was a typical small drafting room with a modern internally illuminated tracing table occupying one corner. The walls were covered with elaborate and obscure graphs, interspersed with photographs of rockets removing themselves spectacularly to distant parts. A place of honor was given to a magnificent view of the Earth from a height of at least a thousand miles. Dirk guessed it was a still from the film that Matthews had arranged for him to see. On Collins’s desk was a photograph of quite a different sort—a portrait of a very pretty girl whom Dirk thought he had seen once or twice at lunch. Collins must have noticed his interest, but as he didn’t elucidate Dirk guessed that he was still unmarried and, like himself, an optimistic bachelor.

  “I suppose,” the aerodynamicist said presently, “you’ve seen our film, ‘The Road to Space’?”

  “Yes, I thought it was very good.”

  “It saves a lot of talking and puts over the basic ideas pretty clearly. But of course it’s rather out-of-date now, and I guess you’re still very much in the dark about the latest developments—particularly the atomic drive in the ‘Prometheus.’ “

  “That’s true,” said Dirk. “It’s a complete mystery to me.”

  Collins gave a puzzled little grin.

  “That baffles us,” he complained. “From the technical point of view, it’s far simpler than the internal combustion engine which everyone understands perfectly. But for some reason, people assume that an atomic drive must be incomprehensible, so they won’t even make an effort to understand it.”

  “I’ll make the effort,” Dirk laughed. “It’s up to you to do the rest. But please remember—I want to know only just enough to follow what’s happening. I’ve no intention of setting myself up as a designer of spaceships!”

  3

  “I suppose I can assume,” said Collins, a little doubtfully, “that you’re quite happy about common-or-garden rockets and understand how they work in a vacuum?”

  “I can see,” replied Dirk, “that if you throw a lot of matter away from you at great speed, there’s bound to be a recoil.”

  “Good. It’s amazing how many people still seem to think that a rocket has to have ‘something to push against,’ as they invariably put it. You’ll appreciate, then, that a rocket designer is always trying to get the maximum possible velocity—and a bit more—from the jet which drives his machine forward. Obviously, the speed of the exhaust determines the velocity which his rocket will attain.

  “The old chemical rockets, like V.2, had jet speeds of one or two miles a second. With such performances, to carry a load of one ton to the Moon and back would have needed several thousand tons of fuel, which wasn’t practicable. What everyone wanted was a weightless fuel supply. Atomic reactions, which are a million or more times as powerful as chemical ones, virtually gave us this. The energy released by the few pounds of matter in the first atomic bombs could have taken a thousand tons to the Moon—and back.

  “But though the energy had been released, no one knew exactly how to use it for propulsion. That little problem has only just been solved, and it’s taken thirty years to produce the very inefficient atomic rockets we have today.

  “Look at the problem from this point of view. In the chemical rocket, we get our driving exhaust by burning a fuel and letting the hot gases acquire speed by expanding through a nozzle. In other words, we exchange heat for velocity—the hotter our combustion chamber, the faster the jet will leave it. We’d get the same result if we didn’t actually burn the fuel at all, but heated the combustion chamber from some outside source. In other words, we could make a rocket by pumping any gas we liked—even air—into a heating unit, and then letting it expand through a nozzle. O.K.?”

  “Yes, that’s straightforward enough so far.”

  “Very well. Now as you know, you can get as much heat as you like out of an atomic pile by making it of richer and richer materials. If you overdo it, of course, the pile will melt down into a puddle of liquid uranium with carbon bobbing about on the surface. Long before that sort of thing happened, any sensible man would have got hull-down over the horizon.”

  “You mean it might go up like an atomic bomb?”

  “No, it couldn’t do that. But an unapproachable radioactive furnace could be just as nasty in its quiet way. However, don’t look so alarmed—this couldn’t happen if the most elementary precautions were taken.

  “We had, then, to design some kind of atomic reactor which would heat a gas stream to a very high temperature indeed—at least 4,000 degrees Centigrade. Since all known metals melt a long way below this, the problem gave us a bit of a headache!

  “The answer we produced is called the ‘line-focused reactor.’ It’s a long, thin, plutonium pile, and gas is pumped in at one end and becomes heated as it travels through. The final result is a central core of intensely hot gas into which we can concentrate or focus the heat from the surrounding elements. In the middle the jet temperature is over 6,000 degrees—hotter than the sun—but where it touches the walls it’s only a quarter of this.

  “So far, I haven’t said what gas we’re going to use. I think you’ll realize that the lighter it is—strictly speaking, the lower its molecular weight—the faster it will be moving when it comes out of the jet. Since hydrogen is the lightest of all elements, it would be the ideal fuel, with helium a fairly good runner-up. I ought to explain, by the way, that we still use the world ‘fuel,’ even though we don’t actually burn it but simply use it as a working fluid.”

  “That’s one thing that had me puzzled,” confessed Dirk. “The old chemical rockets carried their own oxygen tanks, and it’s a bit disconcerting to find that the present machines don’t do anything of the sort.”

  Collins laughed.

  “We could even use helium as a ‘fuel,’ ” he said, “though that won’t burn at all—or indeed take part in any chemical reaction.

  “Now although hydrogen’s the ideal working fluid, as I called it, it’s impossible stuff to carry round. In the liquid state it boils at a fantastically low temperature, and it’s so light that a spaceship would have to have fuel tanks the size of gasometers. So we carry it combined with carbon in the form of liquid methane—CH4—which isn’t hard to handle and has a reasonable density. In the reactor it breaks down to carbon and hydrogen. The carbon’s a bit of a nuisance, and tends to clog the works, but it can’t be helped. Every so often we get rid of it by turning off the main jet and flushing out the motor with a draft of oxygen. It makes quite a pretty firework display.

  “That, then, is the principle of the spaceship’s motors. They give exhaust speeds three times that of any chemical rocket, but even so, we still have to carry a tremendous a
mount of fuel. And there are all sorts of other problems I’ve not mentioned: shielding the crew from the pile radiations was the worst.

  ” ‘Alpha,’ the upper component of the ‘Prometheus,’ weighs about three hundred tons of which two hundred and forty are fuel. If it starts from an orbit around the Earth, it can just make the landing on the Moon and return with a small reserve.

  “It has, as you know, to be carried up to that orbit by ‘Beta.’ ‘Beta’ is a very heavy, super-high-speed flying-wing, also powered by atomic jets. She starts as a ramjet, using air as ‘fuel,’ and only switches over to her methane tanks when she leaves the top of the atmosphere. As you’ll realize, not having to carry any fuel for the first stage of the journey helps things enormously.

  “At take-off, the ‘Prometheus’ weighs five hundred tons, and is not only the fastest but the heaviest of all flying machines. To get it airborne, Westinghouse have built us a five-mile-long electric launching track out in the desert. It cost nearly as much as the ship itself, but of course it will be used over and over again.

  “To sum up, then: we launch the two components together and they climb until the air’s too thin to operate the ramjets any more. ‘Beta’ then switches over to her fuel tanks and reaches circular velocity at a height of about three hundred miles. ‘Alpha,’ of course, hasn’t used any fuel at all—in fact, its tanks are almost empty when ‘Beta’ carries it up.

  “Once the ‘Prometheus’ has homed on the fuel containers we’ve got circling up there, the two ships separate, ‘Alpha’ couples up to the tanks with pipe-lines and pumps the fuel aboard. We’ve already practiced this sort of thing and know it can be done. Orbital refuelling, it’s called, and it’s really the key to the whole problem, because it lets us do the job in several stages. It would be quite impossible to build one huge spaceship that would make the journey to the Moon and back on a single load of fuel.

  “Once ‘Alpha’s’ tanked up, it runs its motors until it’s built up the extra two miles a second to get out of its orbit and go to the Moon. It reaches the Moon after four days, stays there a week and then returns, getting back into the the same orbit as before. The crew transfers to ‘Beta,’ which is still patiently circling with her very bored pilot (who won’t get any of the publicity) and is brought down to Earth again. And that’s all there is to it. What could be simpler?”

  “You make me wonder,” laughed Dirk, “why it hasn’t been done years ago.”

  “That’s the usual reaction,” said Collins in mock disgust.

  “It’s not easy for outsiders to realize the terrific problems that had to be overcome in almost every stage of the work. That’s where the time and money went. It wouldn’t have been possible, even now, without the world-wide research that’s been going on for the last thirty years. Most of our job was collecting the results of other people’s work and adapting them to our use.”

  “How much,” said Dirk thoughtfully, “would you say the ‘Prometheus’ cost?”

  “It’s almost impossible to say. The research of the world’s laboratories for two generations, right back to the 1920’s, has gone into the machine. You should include the two billion dollars the atomic bomb project cost, the hundreds of millions of marks the Germans put into Peenemtinde, and the scores of millions of pounds the British government spent on the Australian range.”

  “I agree, but you must have some idea of the money that actually went into the ‘Prometheus’ itself.”

  “Well, even there we got quite priceless technical assistance—and equipment—for nothing. However, Professor Maxton once calculated that the ship’s cost about ten million pounds in research and five millions in direct construction. That means, someone pointed out, that we’re buying the Moon for a pound a square mile! It doesn’t seem a lot, and of course the later ships will be a good deal cheaper. Incidentally, I believe we’re almost recovering our expenses for the first trip on the film and radio rights! But who cares about the money, anyway?”

  His eyes wandered towards that photograph of the distant Earth, and his voice became suddenly thoughtful.

  “We’re gaining the freedom of the whole Universe, and all that that implies. I don’t think it can be valued in terms of pounds and dollars. In the long run, knowledge always pays for itself in hard cash—but it’s still absolutely beyond price.”

  4

  Dirk’s meeting with Professor Maxton and Raymond Collins marked an unconscious turning point in his thinking, and indeed in his way of life. He felt, perhaps wrongly, that he had now found the source of the ideas which McAndrews and Matthews had passed on to him at secondhand.

  No one could have been more unlike the coldly passionless scientist of fiction than the Deputy Director-General. He was not only a first-class engineer, but he was obviously fully aware of the implications of his work. It would be a fascinating study to discover the motives which had led him, and his colleagues, into this field. The quest for personal power did not seem a likely explanation in the cases that Dirk had met. He must guard against wishful thinking, but these men seemed to have a disinterested outlook which was very refreshing. Interplanetary was inspired by a missionary zeal which technical competence and a sense of humor had preserved from fanaticism.

  Dirk was still only partly aware of the effects his new surroundings were having on his own character. He was losing much of his diffidence; the thought of meeting strangers, which not long ago had filled him with mild apprehension or at least with annoyance, no longer worried him at all. For the first time in his life, he was with men who were shaping the future and not merely interpreting the dead past. Though he was only an onlooker, he was beginning to share their emotions and to feel with their triumphs and defeats.

  “I’m quite impressed,” he wrote in his Journal that evening, “by Professor Maxton and his staff. They seem to have a much clearer and wider view of Interplanetary’s aims than the non-technical people I’ve met. Matthews, for instance, is always talking about the scientific advances which will come when we reach the Moon. Perhaps because they take that sort of thing for granted, the scientists themselves seem more interested in the cultural and philosophical repercussions. But I mustn’t generalize from a few cases which may not be typical.

  “I feel that I’ve now a pretty clear view of the whole organization. It’s now mostly a matter of filling in details, and I should be able to do that from my notes and the mass of photostats I’ve collected. I no longer have the impression of being a stranger watching some incomprehensible machine at work. In fact, I now feel that I’m almost a part of the organization—though I mustn’t let myself get too involved. It’s impossible to be neutral, but some detachment is necessary.

  “Until now I’ve had various doubts and reservations concerning space flight. I felt, subconsciously, that it was too big a thing for man. Like Pascal, I was terrified by the silence and emptiness of infinite space. I see now that I was wrong.

  “The mistake I made was the old one of clinging to the past. Today I met men who think as naturally in millions of miles as I do in thousands. Once there was a time when a thousand miles was a distance beyond all comprehension, yet now it is the space we cover between one meal and the next. That change of scale is about to occur again—and with unprecedented swiftness.

  “The planets, I see now, are no further away than our minds will make them. It will take the ‘Prometheus’ a hundred hours to reach the Moon, and all the time she will be speaking to Earth and the eyes of the world will be upon her. How little a thing interplanetary travel seems if we match it against the weeks and the months and the years of the great voyages of the past!

  “Everything is relative, and the time will surely come when our minds embrace the Solar System as now they do the Earth. Then, I suppose, when the scientists are looking thoughtfully towards the stars, many will cry: ‘We don’t want interstellar flight! The nine planets were good enough for our grandfathers and they’re good enough for us!’ “

  Dirk laid his pen down
with a smile and let his mind wander in the realms of fantasy. Would Man ever face that stupendous challenge and send his ships into the gulf between the stars? He remembered a phrase he had once read: “Interplanetary distances are a million times as great as those to which we are accustomed in everyday life, but interstellar distances are a million-fold greater still.” His mind quailed before the thought, but still he clung to that phrase: ” Everything is relative.” In a few thousand years, Man had come from coracle to spaceship. What might he yet do in the eons that lay ahead?

  5

  It would be false to suggest that the five men on whom the eyes of the world were now fixed regarded themselves as daring adventurers about to risk their fives in a stupendous scientific gamble. They were all practical, hard-headed technicians who had no intention of taking part in a gamble of any kind—at least, where their lives were concerned. There was a risk, of course, but one took risks when one caught the 8.10 to the City.

  Each had reacted in his own way to the publicity of the past week. They had expected it, and they had been well prepared. Hassell and Leduc had been in the public eye before and knew how to enjoy the experience while avoiding its more annoying aspects. The other three members of the crew, having fame thrust suddenly upon them, showed a tendency to huddle together for mutual protection. This move was fatal, as it made them easy meat for reporters.

  Clinton and Taine were still sufficiently unused to the experience of being interviewed to enjoy it, but their Canadian colleague Jimmy Richards hated it. His replies, none too helpful at the beginning, became progressively more and more brusque as time went by and he grew tired of answering the same questions ad nauseam. On one famous occasion, when harried by a particularly overbearing lady reporter, his behavior became somewhat less than gallant.

  According to the description later circulated by Leduc, the interview went something like this:

  “Good morning, Mr. Richards. I wonder if you’d mind answering a few questions for the West Kensington Clarion?”