Rocket Ship Galileo

by Robert A. Heinlein

  “You’re looking at it wrong,” Ross corrected him. “It says 14,400 miles per hour.”

  “You’re crazy.”

  “Like fun. Your eyes have gone bad.”

  “Easy, boys, easy,” Cargraves counseled. “You are looking at different instruments. What kind of speed do you want?”

  “I want to know how fast we’re going,” Art persisted.

  “Now, Art, I’m surprised at you. After all you’ve had every one of these instruments apart. Think what you’re saying.”

  Art stared at the instrument board again, then looked sheepish. “Sure, I forgot. Let’s see now—we’ve gained 14,000 and some, close to 15,000 now, miles per hour in free fall—but we’re not falling.”

  “We’re always falling,” Morrie put in, smug for the moment in his status as a pilot. “You fall all the time from the second you take off, but you drive to beat the fall.”

  “Yes, yes, I know,” Art cut him off. “I was just mixed up for a moment. Thirty-three hundred is the speed I want—3310 now.”

  ‘Speed’ in space is a curiously slippery term, as it is relative to whatever point you select as ‘fixed’—but the points in space are never fixed. The speed Art settled for was the speed of the Galileo along a line from the earth to their meeting place with the moon. This speed was arrived at deep inside Joe the Robot by combining by automatic vector addition three very complicated figures: first was the accumulated acceleration put on the ship by its jet drive, second the motions imposed on the ship by its closeness to the earth—its ‘free fall’ speed of which Art had spoken. And lastly, there was the spin of the earth itself, considered both in amount and direction for the time of day of the take-off and the latitude of the camp site in New Mexico. The last was subtracted, rather than added, insofar as the terms of ordinary arithmetic apply to this sort of figuring.

  The problem could be made vastly more complicated. The Galileo was riding with the earth and the moon in their yearly journey around the sun at a speed of about 19 miles per second or approximately 70,000 miles per hour as seen from outer space. In addition, the earth-moon line was sweeping around the earth once each month as it followed the moon—but Joe the Robot had compensated for that when he set them on a course to where the moon would be rather than where it was.

  There were also the complicated motions of the sun and its planets with reference to the giddily whirling ‘fixed’ stars, speeds which could be nearly anything you wanted, depending on which types of stars you selected for your reference points, but all of which speeds are measured in many miles per second.

  But Joe cared nothing for these matters. His cam and his many circuits told him how to get them from the earth to the moon; he knew how to do that and Doctor Einstein’s notions of relativity worried him not. The mass of machinery and wiring which made up his being did not have worry built into it. It was, however, capable of combining the data that came to it to show that the Galileo was now moving somewhat more than 3300 miles per hour along an imaginary line which joined earth to the point where the moon would be when they arrived.

  Morrie could check this figure by radar observations for distance, plus a little arithmetic. If the positions as observed did not match what Joe computed them to be, Morrie could feed Joe the corrections and Joe would accept them and work them into his future calculations as placidly and as automatically as a well-behaved stomach changes starch into sugar.

  “Thirty-three hundred miles per hour,” said Art. “That’s not so much. The V-2 rockets in the war made more than that. Let’s open her up wide and see what she’ll do. How about it, Doc?”

  “Sure,” agreed Ross, “we’ve got a clear road and plenty of room. Let’s bust some space.”

  Cargraves sighed. “See here,” he answered, “I did not try to keep you darned young speed demons from risking your necks in that pile of bailing wire you call an automobile, even when I jeopardized my own life by keeping quiet. But I’m going to run this rocket my way. I’m in no hurry.”

  “Okay, okay, just a suggestion,” Ross assured him. He was quiet for a moment, then added, “But there’s one thing that bothers me—”

  “What?”

  “Well, if I’ve read it once, I’ve read it a thousand times, that you have to go seven miles per second to get away from the earth. Yet here we are going only 3300 miles per hour.”

  “We’re moving, aren’t we?”

  “Yeah, but—”

  “As a matter of fact we are going to build up a lot more speed before we start to coast. We’ll make the first part of the trip much faster than the last part. But suppose we just held our present speed—how long would it take to get to the moon?”

  Ross did a little fast mental arithmetic concerning the distance of the moon from the earth, rounding the figure off to 240,000 miles. “About three days.”

  “What’s wrong with that? Never mind,” Cargraves went on. “I’m not trying to be a smart Aleck. The misconception is one of the oldest in the book, and it keeps showing up again, every time some non-technical man decides to do a feature story on the future of space travel. It comes from mixing up shooting with rocketry. If you wanted to fire a shot at the moon, the way Jules Verne proposed, it would have to go seven miles per second when it left the gun or it would fall back. But with a rocket you could make the crossing at a slow walk if you had enough power and enough fuel to keep on driving just hard enough to keep from falling back. Of course it would raise Cain with your mass-ratio. But we’re doing something of that sort right now. We’ve got tower to spare; I don’t see why we should knock ourselves out with higher acceleration than we have to just to get there a little sooner. The moon will wait. It’s waited a long time.

  “Anyhow,” he added, “no matter what you say and no matter how many physics textbooks are written and studied, people still keep mixing up gunnery and rocketry. It reminds me of that other old chestnut—about how a rocket can’t work out in empty space, because it wouldn’t have anything to push on.

  “Go ahead and laugh!” Cargraves continued, seeing their expressions, “It strikes you as funny as a The-World-Is-Flat theory. But I heard an aeronautical engineer, as late as 1943, say just that.”

  “No! Not really!”

  “I certainly did. He was a man with twenty-five years of professional experience and he had worked for both Wright Field and the Navy. But he said that in 1943. Next year the Nazis were bombing London with V-2s. Yet according to him it couldn’t be done!”

  “I’d think any man who had ever felt the kick of a shotgun would understand how a rocket works,” Ross commented.

  “It doesn’t work out that way. Mostly it has no effect on his brain cells; it just gives him a sore shoulder.” He started to lift himself out of his semi-reclining position in his pilot’s chair. “Come on. Let’s eat. Wow! My foot’s gone to sleep. I want to stock up and then get some sleep. Breakfast wasn’t much good for me—too many people staring down our necks.”

  “Sleep?” said Art. “Did you say ‘sleep’? I can’t sleep; I’m too excited. I don’t suppose I’ll sleep the whole trip.”

  “Suit yourself. Me, I’m going to soak up shut-eye just as soon as we’ve eaten. There’s nothing to see now, and won’t be until we go into free fall. You’ve had better views of the moon through a telescope.”

  “It’s not the same thing,” Art pointed out.

  “No, it’s not,” Cargraves conceded. “Just the same, I intend to reach the moon rested up instead of worn out. Morrie, where did you stow the can openers?”

  “I—” Morrie stopped and a look of utter consternation came over his face. “I think I left them behind. I put them down on the sink shelf and then some female reporter started asking me some fool question and—”

  “Yeah, I saw,” Ross interrupted him. “You were practically rolling over and playing dead for her. It was cute.”

  Cargraves whistled tunelessly. “I hope that we find out that we haven’t left behind anything really indispensable.
Never mind the can openers, Morrie. The way I feel I could open a can with my bare teeth.”

  “Oh, you won’t have to do that, Doc,” Morrie said eagerly. “I’ve got a knife with a gadget for—” He was feeling in his pocket as he talked. His expression changed abruptly and he withdrew his hand. “Here are the can openers, Doc.”

  Ross looked at him innocently. “Did you get her address, Morrie?”

  Supper, or late breakfast, as the case may be, was a simple meal, eaten from ration cans. Thereafter Cargraves got out his bedding roll and spread it on the bulkhead—now a deck—which separated the pilot compartment from the hold. Morrie decided to sleep in his co-pilot’s chair. It, with its arm rests, head support, and foot rest, was not unlike an extremely well-padded barber’s chair for the purpose, one which had been opened to a semi-reclining position. Cargraves let him try it, cautioning him only to lock his controls before going to sleep.

  About an hour later Morrie climbed down and spread his roll beside Cargraves. Art and Ross slept on their acceleration hammocks, which were very well adapted to the purpose, as long as the occupant was not strapped down.

  Despite the muted roar of the jet, despite the excitement of being in space, they all were asleep in a few minutes. They were dead tired and needed it.

  During the ‘night’ Joe the Robot slowly reduced the drive of the jet as the pull of the earth grew less.

  Art was first to awaken. He had trouble finding himself for a moment or two and almost fell from his hammock on to the two sleepers below before he recollected his surroundings. When he did it brought him wide awake with a start. Space! He was out in space!—Headed for the moon!

  Moving with unnecessary quiet, since he could hardly have been heard above the noise of the jet in any case and since both Ross and Cargraves were giving very fair imitations of rocket motors themselves, he climbed out of the hammock and monkey-footed up to the pilots’ seats. He dropped into Morrie’s chair, feeling curiously but pleasantly light under the much reduced acceleration.

  The moon, now visibly larger and almost painfully beautiful, hung in the same position in the sky, such that he had to let his gaze drop as he lay in the chair in order to return its stare. This bothered him for a moment—how were they ever to reach the moon if the moon did not draw toward the point where they were aiming?

  It would not have bothered Morrie, trained as he was in a pilot’s knowledge of collision bearings, interception courses, and the like. But, since it appeared to run contrary to common sense, Art worried about it until he managed to visualize the situation somewhat thus: if a car is speeding for a railroad crossing and a train is approaching from the left, so that their combined speeds will bring about a wreck, then the bearing of the locomotive from the automobile will not change, right up to the moment of the collision.

  It was a simple matter of similar triangles, easy to see with a diagram but hard to keep straight in the head. The moon was speeding to their meeting place at about 2000 miles an hour, yet she would never change direction; she would simply grow and grow and grow until she filled the whole sky.

  He let his eyes rove over her face, naming the lovely names in his mind, Mare Tranquilitatis, Oceanus Procellarum, the lunar Apennines, LaGrange, Ptolemæus, Mare Imbrium, Catharina. Beautiful words, they rolled on the tongue.

  He was not too sure of the capitals of all the fifty-one United States and even naming the United Nations might throw him, but the geography—or was it lunography?—of the moon was as familiar to him as the streets of his home town.

  This face of the moon, anyway—he wondered what the other face was like, the face the earth has never seen.

  The dazzle of the moon was beginning to hurt his eyes; he looked up and rested them on the deep, black velvet of space, blacker by contrast with the sprinkle of stars.

  There were few of the really bright stars in the region toward which the Galileo was heading. Aldebaran blazed forth, high and aft, across the port from the moon. The right-hand frame of the port slashed through the Milky Way and a small portion of that incredible river of stars was thereby left visible to him. He picked out the modest lights of Aries, and near mighty Aldebaran hung the ghostly, fairy Pleiades, but dead ahead, straight up, were only faint stars and a black and lonely waste.

  He lay back, staring into this remote and solitary depth, vast and remote beyond human comprehension, until he was fascinated by it, drawn into it. He seemed to have left the warmth and safety of the ship and to be plunging deep into the silent blackness ahead.

  He blinked his eyes and shivered, and for the first time felt himself wishing that he had never left the safe and customary and friendly scenes of home. He wanted his basement lab, his mother’s little shop, and the humdrum talk of ordinary people, people who stayed home and did not worry about the outer universe.

  Still, the black depths fascinated him. He fingered the drive control under his right hand. He had only to unlock it, twist it all the way to the right, and they would plunge ahead, nailed down by unthinkable acceleration, and speed on past the moon, too early for their date in space with her. On past the moon, away from the sun and the earth behind them, on an on and out and out, until the thorium burned itself cold or until the zinc had boiled away, but not to stop even then, but to continue forever into the weary years and the bottomless depths.

  He blinked his eyes and then closed them tight, and gripped both arms of the chair.

  THE METHOD OF SCIENCE

  • 10 •

  “ARE YOU ASLEEP?” THE VOICE in his ear made Art jump; he had still had his eyes closed—it startled him. But it was only Doc, climbing up behind him.

  “Oh! Good morning, Doc. Gee, I’m glad to see you. This place was beginning to give me the jim-jams.”

  “Good morning to you, if it is morning. I suppose it is morning, somewhere.” He glanced at his watch. “I’m not surprised that you got the willies, up here by yourself. How would you like to make this trip by yourself?”

  “Not me.”

  “Not me, either. The moon will be just about as lonely but it will feel better to have some solid ground underfoot. But I don’t suppose this trip will be really popular until the moon has some nice, noisy night clubs and a bowling alley or two.” He settled himself down in his chair.

  “That’s not very likely, is it?”

  “Why not? The moon is bound to be a tourists’ stop some day—and have you ever noticed how, when tourists get somewhere new, the first thing they do is to look up the same kind of entertainments they could find just as easily at home?”

  Art nodded wisely, while tucking the notion away in his mind. His own experience with tourists and travel was slight—until now! “Say, Uncle, do you suppose I could get a decent picture of the moon through the port?”

  Cargraves squinted up at it. “Might. But why waste film? They get better pictures of it from the earth. Wait until we go into a free orbit and swing ship. Then you can get some really unique pics—the earth from space. Or wait until we swing around the moon.”

  “That’s what I really want! Pictures of the other side of the moon.”

  “That’s what I thought.” Cargraves paused a moment and then added, “But how do you know you can get any?”

  “But… Oh, I see what you mean. It’ll be dark on that side.”

  “That’s not exactly what I meant, although that figures in, too, since the moon will be only about three days past ‘new moon,’ ‘new moon,’ that is, for the other side. We’ll try to time it to get all the pics you want on the trip back. But that isn’t what I mean: how do you know there is any back side to the moon? You’ve never seen it. Neither has any one else, for that matter.”

  “But—there has to—I mean, you can see…”

  “Did I hear you say there wasn’t any other side to the moon, Doc?” It was Ross, whose head had suddenly appeared beside Cargraves.

  “Good morning, Ross. No, I did not say, there was no other side to the moon. I had asked Art to tell me w
hat leads him to think there is one.”

  Ross smiled. “Don’t let him pull your leg, Art. He’s just trying to rib you.”

  Cargraves grinned wickedly. “Okay, Aristotle, you picked it. Suppose you try to prove to me that there is a far side to the moon.”

  “It stands to reason.”

  “What sort of reason? Have you ever been there? Ever seen it?”

  “No, but—”

  “Ever met anybody who’s ever seen it? Ever read any accounts by anybody who claimed to have seen it?”

  “No, I haven’t, but I’m sure there is one.”

  “Why?”

  “Because I can see the front of it.”

  “What does that prove? Isn’t your experience, up to now, limited to things you’ve seen on earth? For that matter I can name a thing you’ve seen on earth that hasn’t any back side.”

  “Huh? What sort of a thing? What are you guys talking about?” It was Morrie this time, climbing up on the other side.

  Art said, “Hi, Morrie. Want your seat?”

  “No, thanks. I’ll just squat here for the time being.” He settled himself, feet dangling. “What’s the argument?”

  “Doc,” Ross answered, “is trying to prove there isn’t any other side to the moon.”

  “No, no, no,” Cargraves hastily denied. “And repeat ‘no.’ I was trying to get you to prove your assertion that there was one. I was saying that there was a phenomenon even on earth which hasn’t any back side, to nail down Ross’s argument from experience with other matters—even allowing that earth experience necessarily applies to the moon, which I don’t.”

  “Whoops! Slow up! Take the last one first. Don’t natural laws apply anywhere in the universe?”

  “Pure assumption, unproved.”

  “But astronomers make predictions, eclipses and such, based on that assumption—and they work out.”

  “You’ve got it backwards. The Chinese were predicting eclipses long before the theory of the invariability of natural law was popular. Anyhow, at the best, we notice certain limited similarities between events in the sky and events on earth. Which has nothing to do with the question of a back side of the moon which we’ve never seen and may not be there.”