by Hal Clement
The thought struck him again. Did they want him to get anywhere? What had Lerch said so long ago about these people? They wanted to get in first to make their own claims, he had insisted. They had denied it, of course; but they were keeping him back, just the same. How did he know that he would not wake up some morning to find the other boys millions of miles on their ways to make just that claim? He had been a fool; he had swallowed Bowen's apparent friendliness too easily. Something had to be done, and Tumble Tighe was the one to do it.
His face firmed into decision under the red thatch of hair, and the boy turned suddenly and left the dock. He had finished thinking; it was time for action.
The Tumblesauce, like her sister ships, had emergency food aboard; it was always possible that a motor would fail, and the pilot might want to eat while the rescuers were coming. Tumble had heard of emergency foods, however, and decided that it would be more comfortable to add some of the things he liked. He did this at odd times during the next week or so, when he was sure the others were too busy to notice him.
He checked the fuel tanks. Fuel was a minor problem with a Phoenix reactor, but his training had impressed on him that nothing about machinery should be left to chance. He went over in his mind the navigation problem involved—he didn't dare ask for help from either his instructor or Peter. He did work some of it out on paper, but carefully burned the paper afterward. The real trouble, of course, was not in finding the moon but in arranging to get there traveling slowly enough so that he would not blow a new hole in its already pitted surface. That was where gravity both of Earth and moon complicated matters; but Tumble was sure he had figured it correctly. Nine days' spare time went to this job.
There was just one more thing to do. He almost laughed as he realized that it was the part of ground school he disliked the most which had taught him to do it. Well, if they wanted him to learn about radios, he would show them!
He waited until the next morning before showing anyone, however. He was sensible enough to know that he would need the sleep, impatient as he was. Then, after breakfast, he joined the others at the dock. They all carefully checked their space suits, as had now become routine; each one got into his own rocket, and one by one the little machines dropped through their hatches.
Tumble did not listen while his instructor outlined the maneuver he was to try next. Instead, he had the cover off the receiver which picked up the control impulses from the station; and working very carefully, for he did not know whether the plastic of his space suit was sufficient insulation against four hundred volts, he slipped the main fuse out of its clip. Being a rather neat young fellow, he put the fuse into the repair kit and the cover back on the set; then, without saying a word to his instructor, he swung the Tumblesauce around so that her nose pointed just ahead of the moon on the latter's path among the stars, and cut in two gravities of drive.
15
BULL'S-EYE—ALMOST
THE instructor could not, of course, see Tumble's rocket directly—had he been near a porthole, which he wasn't, the little machine would have been out of sight of the station a few seconds after launching. Even the gleam of sunlight on its bright hull could not be distinguished among the thousands of stars, if it were more than a mile or two away. For that reason, the instructor did not realize what the boy had done for more than a minute. He had been outlining the maneuver that the Tumblesauce was to perform; when he had finished, he waited for an answer, and got none.
"Tumble! Come in! Did you read me?" He paused, then repeated his calls; and when silence continued on the Tumblesauce's wave length, he cut in the circuits which tied his vision screen to the search radar of the station.
Four dots immediately glowed on various parts of the screen; but one was much fainter than the others. Shaking his head, the instructor snapped over to another circuit, and five seconds later had the distance and speed of the fleeing speck of metal. At the instant of the measurement, it had been just over thirty-five miles from the station, traveling away at almost exactly one mile per second.
His hands flew over the controls which should have spun the errant rocket end for end and started its main motor at the task of slowing down its mad flight; but thirty seconds after the first observation its distance was seventy-three miles, while more than thirty percent had been added to its speed.
"Tumble, are you out of control? Tell us please— at least send out a carrier wave; you'll be out of our radar range before long, and if anyone is going to find you with a rescue ship he'll need something to guide him."
"I'm not out of control." The words came firmly, but with no suggestion that the speaker intended to say any more.
"Then come back, for goodness' sake. You don't know what you're getting yourself into."
"I know all right. I'm tired of doing loop-the-loops according to instructions. I'll be back in a few days. There's something I've been wanting to see for a long time, and I'm going to get a good look at it."
The instructor had sounded a general alarm the moment he had finished his first check on the Tumblesauce s position and speed; at this point Bowen appeared in answer to it. A few seconds' explanation gave him the facts, and he shook his head.
"We won't be able to talk him back," he remarked. Then, into the microphone, "Tumble, you're not ready for this, whatever you may think. Please remember that making a landing where there's any gravity to speak of is a lot different from matching up with this station...."
"Who told you where I was landing?"
"You did. Time and again. I don't suppose you believe anything I'm saying, though, so I'll ask just one thing; please promise to call us if you even suspect you may be in trouble, so that we'll know about where you are and what sort of help you'll need."
"I won't get in trouble." The boy paused, then added, "I'll call you, though, anyway. I'll be seeing a lot that you'll want to hear."
Bowen shook his head at that.
"All right; thanks. Just be sure your space suit is all right before you try that landing. It probably won't make any difference, but it might." He signed off with that remark, and that was probably the best thing he could have done.
Certainly it made Tumble think for some seconds. He admitted later that he almost reached for the controls, to reverse the flight of the little rocket, but before he did so, his eyes fell on the moon above his head.
That was enough. He had seen pictures of it, he had gazed at it through telescopes; no one was going to stop him from visiting it now. He knew about allowing for gravity; he had done the problem, or ones like it, several times on paper in the last few days in preparation for this very event. He made a face at the radio, and settled himself to the task of piling up distance.
At two gravities acceleration—in other words, adding more than forty miles an hour to his speed each second —covering great distances is not a difficult job. One hour after turning on his power, he was nearly eighty thousand miles from both the station and the earth, and his speed had built up to over forty-three miles a second. Another hour would have doubled his speed and quadrupled his distance, placing the TumbJesauce well beyond the moon.
Tumble did not keep going, therefore. If there had been no outside forces acting on the ship, turning over at one hour and fourteen minutes from his starting time and decelerating at the same rate he had been using would have brought the little rocket to a halt, relative to its starting point, at two hundred and forty-two thousand miles, the moon's distance at the time. Actually, since he would have been fighting the earth's gravity for most of the distance, the stop would come sooner; therefore he made the turnover a trifle later. He had carefully figured out just when this should be done—it was the problem he had been practicing, and he was very pleased with himself, feeling quite rightly that none of the instructors at the station would expect him to remember the correction.
He forgot two other facts, however. One was that he had set his initial course by eye and had to correct it from time to time; therefore his slowing down wa
s not done in a direction exactly opposite to his speeding up, and did not exactly offset it. This was minor, however; what really caused his trouble was forgetting that the station, at the time he left it, was moving in its orbit about the earth almost directly toward the moon; this fact had made him a free present of approximately four miles a second. This factor, in some eight thousand seconds of flight, added up to quite an error in distance.
Tumble did not find this out until he was about twelve thousand miles from the moon. He might not have realized it then, for he was paying a good deal more attention to the moon than to his navigation, but the ship itself called the matter to his attention.
The rocket was equipped with radar, and in connection with the radar was a tiny automatic calculator which was designed to figure the course of any large object approaching the rocket. It would sound an alarm if the object were on a course which would result in collision; the moment the moon came within the twelve-thousand-mile extreme range of the radar, the alarm sounded.
At first, Tumble paid little attention; he already knew he was heading for the moon, so the alarm was telling him nothing new. Then he remembered that the calculator automatically allowed for any power the ship itself was using, so that the alarm must mean that he was not slowing down rapidly enough. Even this did not surprise him too much; he would have admitted, if anyone had asked him, that he might be a few hundred yards or maybe a mile or two off in his calculations. He increased his power a trifle, expecting the alarm to cut out as soon as the calculator had made allowance for the change, but it kept ringing.
Tumble's next thought was that the alarm equipment must be out of order; he made two more increases of power, until the Tumblesauce was losing speed at nearly a hundred feet per second each second and the boy was sagging in his safety harness under a force of three times his own weight, but the alarm continued to ring. As a final test he started two of the tiny side motors at a power sufficient to push the rocket out of line with the moon in a few minutes. He expected no result from this move, but to his surprise the bell stopped almost at once.
It was hard to think under three gravities of acceleration, but even so he could see what that meant. Somewhere he had made a mistake. He had too much speed; unless he kept a course which would pass to one side of the moon, he would strike its surface much too hard for comfort.
Actually, his instruments were giving him his distance from the moon, his velocity at the moment, and his acceleration; it would have been easy for some people to calculate from their readings how fast he would strike—or, alternately, what acceleration he would need to make a safe landing. Peter, he reflected gloomily, could probably have done the arithmetic in his head (this was a mistake; even Peter had his limits); but Tumble Tighe and Peter Ashburn were two very different people. Tumble had to use trial and error; he kept increasing his main power, and after each increase edged back until his course once more intersected the surface of the moon.
Each time the bell rang again. He kept up the attempts until the Tumblesauce was slowing at nearly six gravities—until Tumble himself was being jammed into his seat by the more than six hundred pounds provided by his own inertia. A grown man would have been unconscious under the force, unless he were lying down at right angles to it; even Tumble, sagging in the control chair with his feet almost as "high" as his head, was barely able to see. He was more frightened than he could remember ever having been in his life; he knew now that his error had not been one of a few feet. It had involved thousands of miles of distance and thousands of feet per second of velocity. At last he stopped edging back toward the moon; if he struck it at his present speed there would be a new crater for someone to name. The only comfort for him was that he would never know it. He and his rocket would be a boiling cloud of gas a thousandth of a second after the blow.
The minutes passed, however, and nothing seemed to happen. With each second, the rocket was going that much more slowly, and its frightened pilot drew a tiny bit of courage from each of those seconds. For more than an hour the moon had been invisible beneath his feet; now it began to show in one of the side windows. That meant that almost certainly he would pass it safely even if he did not stop in time, and with this realization the last of his terror departed. Those few minutes of fear had soaked his clothes with perspiration, and his arms and hands were cramped with the grip he had held on the arms of the pilot chair. But that was just something to forget.
The speed dial on the radar unit dropped to zero, which did not mean that he had stopped but that he was no longer getting any closer to the moon—he was passing it. With some difficulty he moved his head enough to watch it through the port. It was only a few miles away; he had given himself just barely enough sideways velocity. It was moving very slowly, too; and as he watched, it stopped entirely and then began to drift in the opposite direction—toward the stern of the rocket. Tumble realized what that meant, and cut his power at once. He had finally gotten rid of his extra speed.
But that did not mean that he could relax. Fifteen miles above the surface of a world, even one with gravity as weak as the moon's, is no place to take a nap; the Tumblesauce might have stopped as far as her interplanetary speed was concerned, but she was falling.
Tumble swung the tail toward the surface of the moon, and applied enough power to halt the fall—the radar was useful once more. Then he began to ease gently downward. He knew about where he was; he had been aiming at the moon's north pole from the beginning, and must have stopped nearly above it. A quick glance through the ports showed the craters and mountains he had seen so often through the telescope, now standing out sharp and clear. He had trouble recognizing them, since he was seeing them from a direction no human ever had before; but he thought he could identify his favorite Mountains of Eternal Light. He was not right above them, but this was no time to change that; he had a landing to take care of.
The Tumblesauce settled gently downward. Had anyone been watching from outside, he would have seen her rocket exhaust glowing faintly, a line of light that reached downward from her tail and finally touched the surface. A wave of dust and pebbles, glowing with the heat of the stream of gas, washed outward from the point of contact and vanished as the jet swept the rock clear of loose material. Five seconds later Tumble saw his distance scale touch zero; as he cut the power to his main engine, he felt a faint jar. The rocket had fallen perhaps six inches. It stood quietly on its tail, a gleaming metal cylinder, the first man-carrying machine ever to touch the moon.
16
LONG WALK
TUMBLE did not know which window to approach first. From his seat he could catch glimpses of the surrounding landscape through each of them, but every time he started to look closer at one scene, another one glimpsed from the corner of his eye caught his attention. The seat was back in its normal position after holding him nearly horizontal during the period of high acceleration; there was no difficulty about leaving it. He simply couldn't make up his mind which way to go when he did.
The obvious answer finally came to him. He stood up —the gravity did not bother him; he weighed about what he did forty or fifty feet from the center of the station, and had spent plenty of time getting used to that—and started toward the air lock. If Bowen had seen him there would have been an explosion, for he had made numerous and lengthy speeches about the importance of checking the space suits before going outside a ship. Tumble forgot this until he was actually inside the air lock. When he did remember, he was tempted to go on anyway, since the lock was too cramped to let him make a proper check and he had already sealed the inner door, but he remembered the stories he had heard of what happened to living creatures when the pressure went so low that boiling point was below their body temperature, and went back. The check was done rather quickly, but would probably have satisfied Bowen; two minutes later the outer door of the air lock opened and let the boy get his first good look at the moon.
He had somehow expected it to be glaringly bright, as it had always looked in t
he telescopes, but the surface was almost entirely of dark-colored rock. From where he stood he could see nothing looking in the least like soil, but when he worked his way cautiously down the ladder he found that the cracks in the rock were filled with powdery dust. Close to the rocket there was none of this loose on the surface, but farther away a layer of it could be found up to two or three inches thick. Apparently it had been blown away from the landing site by the jet.
In general the surface was fairly smooth in spite of the cracks, but low mountains could be seen in several different directions. He was not sure which, if any, of these were the Mountains of Light he had come to see, but there would be no difficulty in identifying them from above when the time came. Tumble's fear had completely gone by now, and the thought of taking the rocket up again did not bother him in the least.
He had not expected that landscape features would be so hard to recognize from where he was standing. He had studied the north polar region for hours in the telescope at the station, and would have sworn that he knew every major peak and crater in the neighborhood, but they looked very different now. Perhaps the fact that the sun was just barely above the horizon would account for it—but no, the sun never rose very high this close to the pole; even Tumble knew that, though he was no mathematician.
Looking toward the sun brought another thought to his mind, and he began looking around for the earth. It was visible enough, nearly a quarter of the way around the horizon to the right of the sun, and like it just barely above the mountains. It was far brighter than the moon ever appears from the earth, but the fact was not very noticeable with the sun also in the sky. It was rather less than half full, but Tumble could not have said at the moment whether it was coming or going in that respect. It did not occur to him to wonder—it did not seem important at the moment.
