The Space Trilogy

by Arthur C. Clarke

  'But is it safe?' insisted Ruby. 'I've read that your seas are full of horrible monsters that might come up and swallow you.'

  This time I couldn't help smiling.

  'I shouldn't worry,' I replied. 'It hardly ever happens these days.'

  'What about the land animals?' said May. 'Some of those are quite big, aren't they? I've read about tigers and lions, and I know they're dangerous. I'm scared of meeting one of those.'

  Well, I thought, I hope I know a bit more about Mars than you do about Earth! I was just going to explain that man-eating tigers weren't generally found in our cities when I caught Ruby grinning at John—and realized that they'd been pulling my leg all the time.

  After that we all went to lunch together, in a great dining-room where I felt rather ill at ease. I made matters worse by forgetting we were under gravity again and spilling a glass of water on the floor. However, everyone laughed so good humouredly at this that I didn't really mind—the only person who was annoyed was the steward who had to mop it up.

  For the rest of my short stay in the Residential Station I spent almost all my time with the Moores. And it was here, surprisingly enough, that I at last saw something I'd missed on my other trips. Though I'd visited several space-stations, I'd never actually watched one being built. We were now able to get a grandstand view of this operation—and without bothering to wear space-suits. The Residential Station was being extended, and from the windows at the end of the 'Two-Thirds Gravity' floor we were able to see the whole fascinating process. Here was something that I could explain to my new friends: I didn't tell them that the spectacle would have been equally strange to me only two weeks ago.

  The fact that we were making one complete revolution every ten seconds was highly confusing at first, and the girls turned rather green when they saw the stars orbiting outside the windows. However, the complete absence of vibration made it easy to pretend—just as one does on Earth—that we were stationary and it was really the stars that were revolving.

  The Station extension was still a mass of open girders, only partly covered by metal sheets. It had not yet been set spinning, for that would have made its construction impossibly difficult. At the moment it floated about half a mile away from us, with a couple of freight rockets alongside. When it was completed, it would be brought gently up to the Station, and set rotating on its axis by small rocket motors. As soon as the spins had been matched exactly, the two units would be bolted together—and the Residential Station would have doubled its length. The whole operation would be rather like engaging a gigantic clutch.

  As we watched, a construction gang was easing a large girder from the hold of a ferry rocket. The girder was about forty feet long, and though of course it weighed nothing out here, its mass or inertia was unchanged. It took a considerable effort to start it moving—and an equal effort to stop it again. The men of the construction crew were working in what were really tiny spaceships—little cylinders about ten feet long, fitted with low-powered rockets and steering jets. They manoeuvred these with fascinating skill, darting forward or sideways and coming to rest with inches to spare. Ingenious handling mechanisms and pointed metal arms enabled them to carry out all assembling tasks almost as easily as if they were working with their own hands.

  The team was under the radio control of a foreman—or, to give him his more dignified name, a Controller—in a little pressure-hut fixed to the girders of the partly constructed station. As they moved to and fro or up and down under his direction, keeping in perfect unison, they reminded me of a flock of goldfish in a pool. Indeed, with the sunlight glinting on their armour, they did look very much like underwater creatures.

  The girder was now floating free of the ship that had brought it here from the Moon, and two of the men attached their grapples and towed it slowly towards the Station. Much too late, it seemed to me, they began to use their braking units. But there was still a good six inches between the girder and the skeleton framework when they had finished. Then one of the men went back to help his colleagues with the unloading, while the other eased the girder across the remaining gap until it made contact with the rest of the structure. It was not lying in exactly the correct line, so he had to slew it through a slight angle as well. Then he slipped in the bolts and began to tighten them up. It all looked so effortless—but I realized that immense skill and practice must lie behind this deceptive simplicity.

  Before you could go down to Earth, you were supposed to spend a twelve-hour quarantine period on the 'Full Earth Gravity' floor—the outermost of the Station's three decks. So once again I went down one of those curving stairways, my weight increasing with every step. When I had reached the bottom, my legs felt very weak and wobbly. I could hardly believe that this was the normal force of gravity under which I had passed my whole life.

  The Moores had come with me, and they felt the strain even more than I did. This was three times the gravity of their native Mars, and twice I had to stop John falling as he tottered unsteadily about. The third time I failed, and we both went down together. We looked so miserable that after a minute each started laughing at the other's expression, and our spirits quickly revived. For a while we sat on the thick rubber flooring (the designers of the Station had known where it would be needed!) and got up our strength for another attempt. This time, we didn't fall down. Much to John's annoyance, the remainder of his family managed a good deal better than he did.

  We couldn't leave the Residential Station without seeing one of its prize exhibits. The 'Full Earth Gravity' floor had a swimming-pool—a small one, but its fame had spread throughout the Solar System.

  It was famous because it wasn't flat. As I've explained, since the Station's 'gravity' was caused by its spin, the vertical at any spot pointed towards the central axis. Any free water, therefore, had a concave surface, taking in fact the shape of a hollow cylinder.

  We couldn't resist entering the pool—and not merely because once we were floating gravity would be less of a strain. Though I'd become used to many strange things in space, it was a weird feeling to stand with my head just above the surface of the pool, and to look along the water. In one direction—parallel to the axis of the Station, that is—the surface was quite flat. But in the other it was curved upwards on either side of me. At the edge of the pool, in fact, the water level was higher than my head. I seemed to be floating in the trough of a great frozen wave… At any moment I expected the water to come flooding down as the surface flattened itself out. But, of course, it didn't—because it was 'flat' already in this strange gravity field. (When I got back to Earth I made quite a mess trying to demonstrate this effect by whirling a bucket of water round my head at the end of a string. If you try the same experiment, do make sure you're out of doors…)

  We could not play round in that peculiar pool as long as I would have liked, for presently the loudspeakers began to call softly and I knew that my time was running out. All the passengers were asked to check that their luggage was packed, and to assemble in the main hall of the Station. The colonists, I knew, were planning some kind of farewell, and though it didn't really concern me I felt sufficiently interested to go along. After talking to the Moores I'd begun to like them and to understand their point of view a good deal better.

  It was a subdued little gathering that we joined a few minutes later. These weren't tough, confident pioneers any more: they knew that soon they'd be separated and in a strange world, among millions of other human beings with totally different modes of life. All their talk about 'going home' seemed to have evaporated: it was Mars, not Earth, they were homesick for now.

  As I listened to their farewells and little speeches, I felt suddenly very sorry for them. And I felt sorry for myself, because in a few hours I, too, would be saying goodbye to space.

  Twelve

  THE LONG FALL HOME

  I had come up from Earth by myself—but I was going home in plenty of company. There were nearly fifty passengers crowded into the 'One-Third Gravit
y' floor waiting to disembark. That was the complement for the first rocket: the rest of the colonists would be going down on later flights.

  Before we left the Station, we were all handed a bundle of leaflets full of instructions, warnings and advice about conditions on Earth. I felt that it was hardly necessary for me to read through all this, but was quite glad to have another souvenir of my visit. It was certainly a good idea giving these leaflets out at this stage in the homeward journey—for it kept most of the passengers so busily reading that they didn't have tune to worry about anything else until we'd landed.

  The air-lock was only large enough to hold about a dozen people at a time, so it took quite a while to shepherd us all through. As each batch left the Station, the lock had to be set revolving to counteract its normal spin, then it had to be coupled to the waiting spaceship, uncoupled again when the occupants had gone through, and the whole sequence restarted. I wondered what would happen if something jammed while the spinning Station was connected to the stationary ship. Probably the ship would come off worse—next, that is, to the unfortunate people in the airlock! However, I discovered later that there was an additional movable coupling to take care of just such an emergency.

  The Earth ferry was the biggest spaceship I had ever been inside. There was one large cabin for the passengers, with rows of seats in which we were supposed to remain strapped during the trip. Since I was lucky enough to be one of the first to go aboard, I was able to get a seat near a window. Most of the passengers had nothing to look at but each other—and the handful of leaflets they'd been given to read.

  We waited for nearly an hour before everyone was aboard and the luggage had been stowed away. Then the loud-speakers told us to stand-by for take-off in five minutes. The ship had now been completely uncoupled from the Station and had drifted several hundred feet away from it.

  I had always thought that the return to Earth would be rather an anticlimax after the excitement of a take-off.

  There was a different sort of feeling, it was true—but it was still quite an experience. Until now we had been, if not beyond the power of gravity, at least travelling so swiftly in our orbit that Earth could never pull us down. But now we were going to throw away the speed that gave us safety. We would descend until we had re-entered the atmosphere and were forced to spiral back to the surface. If we came in too steeply, our ship might blaze across the sky like a meteor and come to the same fiery end.

  I looked at the tense faces around me. Perhaps the Martian colonists were thinking the same thoughts: perhaps they were wondering what they were going to meet and do down on the planet which so few of them had ever before seen. I hoped that none of them would be disappointed.

  Three sharp notes from the loud-speaker gave us the last warning. Five seconds later the motors opened up gently, quickly increasing power to full thrust. I saw the Residential Station fall swiftly astern, its great spinning drum dwindling against the stars. Then, with a lump in my throat, I watched the untidy maze of girders and pressure chambers that housed so many of my friends go swimming by. Useless though the gesture was, I couldn't help giving them a wave. After all, they knew I was aboard this ship, and might catch a glimpse of me through the window…

  Now the two component parts of the Inner Station were receding rapidly behind us, and soon had passed out of sight under the great wing of the ferry. It was hard to realize that, in reality, we were losing speed while the Station continued on its unvarying way. And as we lost speed, so we would start falling down to Earth on a long curve that would take us to the other side of the planet before we entered the atmosphere.

  After a surprisingly short period, the motors cut out again. We had shed all the speed that was necessary and gravity would do the rest. Most of the passengers had settled down to read, but I decided to have my last look at the stars, undimmed by atmosphere. This was also my last chance of experiencing weightlessness, but it was wasted because I couldn't leave my seat. I did try, and got shooed back by the steward.

  The ship was now pointing against the direction of its orbital motion, and had to be swung round so that it entered the atmosphere nose-first. There was plenty of time to carry out this manoeuvre, and the pilot did it in a leisurely fashion with the low-powered steering jets at the wing-tips. From where I was sitting I could see the short columns of mist stabbing from the nozzles, and very slowly the stars swung around us. It was a full ten minutes before we came to rest again, with the nose of the ship now pointing due east.

  We were still almost five hundred miles above the Equator, moving at nearly eighteen thousand miles an hour. But we were now slowly dropping Earthwards: in thirty minutes we would make our first contact with the atmosphere.

  John was sitting next to me, and so I had a chance of airing my knowledge of geography.

  'That's the Pacific Ocean down there,' I said. And something prompted me to add, not very tactfully: 'You could drop Mars in it without going near either of the coastlines.'

  However, John was too fascinated by the great expanse of water to take any offence. It must have been an overwhelming sight for anyone who had lived on sea-less Mars. There were not even any permanent lakes on that planet—only a few shallow pools that form round the melting ice-caps in the summer. And now John was looking down upon water that stretched as far as he could see in every direction, with a few specks of land dotted upon it here and there.

  'Look!' I said, 'there, straight ahead! You can see the coastline of South America. "We can't be more than two hundred miles up now.'

  Still in utter silence the ship dropped Earthwards and the ocean rolled back beneath us. No one was reading now if they had a chance of seeing from one of the windows. I felt very sorry for the passengers in the middle of the cabin, who weren't able to watch the approaching landscape beneath.

  The coast of South America flashed by in seconds, and ahead lay the great jungles of the Amazon. Here was life on a scale that Mars could not match, not even, perhaps, in the days of its youth. Thousands of square miles of crowded forests, countless streams and rivers—they were unfolding beneath us so swiftly that as soon as one feature had been grasped, it was already out of sight.

  And now the great river was widening as we shot above its course. We were approaching the Atlantic, which should have been visible by this time, but which seemed to be hidden by mists. As we passed above the mouth of the Amazon, I saw that a great storm was raging below. From time to time brilliant flashes of lightning played across the clouds: it was uncanny to see all this happening in utter silence as we raced high overhead.

  'A tropical storm,' I said to John. 'Do you ever have anything like that on Mars?'

  'Not with rain, of course,' he said. 'But sometimes we get pretty bad sandstorms over the deserts. And I've seen lightning once—or perhaps twice.'

  'What, without rain clouds?' I asked.

  'Oh yes—the sand gets electrified. Not very often, but it does happen.'

  The storm was now far behind us, and the Atlantic lay smooth in the evening sun. We could not see it much longer, however—for darkness lay ahead. We were nearing the night side of the planet, and on the horizon I could see a band of shadow swiftly approaching as we hurtled into twilight. There was something terrifying about plunging headlong into that curtain of darkness. In mid-Atlantic, we lost the sun: and at almost the same moment we heard the first whisper of air along the hull.

  It was an eerie sound, and it made the hair rise at the back of my neck. After the silence of space any noise seemed altogether wrong. But it grew steadily, as the minutes passed, from a faint, distant wail to a high-pitched scream. We were still more than fifty miles up, but at the speed we were travelling even the incredibly thin atmosphere of these heights was protesting as we tore through it.

  More than that—it was tearing at the ship, slowing it down. There was a faint but steadily increasing tug from our straps: the deceleration was trying to force us out of our seats. It was like sitting in a car when the brakes are
being slowly applied. But in this case, the braking was going to last for two hours, and we would go once more round the world before we slowed to a halt…

  We were no longer in a spaceship, but an aeroplane. In almost complete darkness—there was no Moon—we passed above Africa and the Indian Ocean. The fact that we were speeding through the night, travelling above the invisible Earth at many thousands of miles an hour, made it all the more impressive. The thin shriek of the upper atmosphere had become a steady background to our flight: it grew neither louder nor fainter as the minutes passed.

  I was looking out into the darkness when I saw a faint red glow beneath me. At first, because there was no sense of perspective or distance, it seemed at an immense depth below the ship, and I could not imagine what it might be.

  A great forest fire, perhaps—but we were now, surely, over the ocean again. Then I realized, with a shock that nearly jolted me out of my seat, that this ominous red glow came from our wing… The heat of our passage through the atmosphere was turning it cherry red.

  I stared at that disturbing sight for several seconds before I decided that everything was really quite in order. All our tremendous energy of motion was being converted into heat—though I had never realized just how much heat would be produced. For the glow was increasing even as I watched: when I flattened my face against the window, I could see part of the leading edge, and it was a bright yellow in places. I wondered if the other passengers had noticed it—or perhaps the little leaflets, which I hadn't bothered to read, had already told them not to worry.

  I was glad when we emerged into daylight once more, greeting the dawn above the Pacific. The glow from the wings was no longer visible, and so ceased to worry me. Besides, the sheer splendour of the sunrise, which we were approaching at nearly ten thousand miles an hour, took away all other sensations. From the Inner Station, I had watched many dawns and sunsets pass across the Earth. But up there, I had been detached, not part of the scene itself. Now I was once more inside the atmosphere and these wonderful colours were all around me.