Islands in the Sky (Arthur C. Clarke Collection)

by Arthur C. Clarke

  The play we saw was Macbeth. Personally, I don’t care for Shakespeare and I went along only because we’d been invited and it would have been rude to stay away. But I was glad I went, if only because it was interesting to see how the patients were enjoying themselves. And not many people can claim that they’ve seen Lady Macbeth, in the sleepwalking scene, coming down the stairs with magnetic shoes!

  Another reason why I was in no great hurry to return to the Inner Station was simply this—in three days’ time I’d have to go aboard the freighter scheduled to take me home. Although I’d been mighty lucky to get out here to the Space Hospital, there were still many things I hadn’t seen. There were the Met Stations, the great observatories with their huge, floating telescopes and the Relay Stations, another seven thousand miles farther out into space. Well, they would simply have to wait for another time.

  Before the ferry rocket arrived to take us home, we had the satisfaction of knowing that our mission had been successful. The patient was off the danger list, and had a good chance of making a complete recovery. But—and this certainly gave the whole thing an ironic twist—it wouldn’t be safe for him to go down to earth. He’d come all these scores of millions of miles for nothing. The best he could do would be to look down on earth through observation telescopes, watching the green fields on which he could never walk again. When his convalescence was over, he’d have to go back to Mars and its lower gravity.

  The ferry rocket that came up to fetch us home had been diverted from its normal run between the Observatory Stations. When we went aboard, Tim Benton was still arguing with the commander. No—arguing wasn’t the right word. No one did that with Commander Doyle. But he was saying, very wistfully, that it really was a great pity that we couldn’t go back in the Morning Star. The commander only grinned. “Wait until you see the report of her overhaul,” he advised. “Then you may change your mind. I bet she needs new tube linings, at the very least. I’ll feel a bit happier in a ship that’s a hundred years younger!”

  Still, as things turned out, I’m pretty sure the commander wished he’d listened to us….

  It was the first time I’d been aboard one of the low-powered inter-orbit ferries, unless one includes our home-built Skylark of Space in this category. The control cabin was much like that of any other spaceship, but from the outside the vessel looked very peculiar. It had been built here in space and, of course, had no streamlining or fins. The cabin was roughly egg-shaped, and connected by three open girders to the fuel tanks and rocket motors. Most of the freight was not taken inside the ship, but was simply lashed to what were rather appropriately called the “luggage racks,” a series of wiremesh nets supported on struts. For stores that had to be kept under normal pressure, there was a small hold with a second air lock just behind the control cabin. The whole ship had certainly been built for efficiency rather than beauty.

  The pilot was waiting for us when we went aboard, and Commander Doyle spent some time discussing our course with him.

  “That’s not his job,” Norman whispered in my ear, “but the old boy’s so glad to be out in space again that he can’t help it.” I was going to say that I thought the commander spent all his time in space; then I realized that from some points of view his office aboard the Inner Station wasn’t so very different from an office down on earth.

  We had nearly an hour before take-off, ample time for all the checks and last-minute adjustments that would be needed. I got into the bunk nearest to the observation port, so that I could look back at the hospital as we dropped away from its orbit and fell down toward earth. It was hard to believe that this great blossom of glass and plastic—floating here in space with the sun pouring into its wards, laboratories and observation decks—was really spinning round the world at eight thousand miles an hour. As I waited for the voyage to begin, I remembered the attempts I’d had to explain the space stations to Mom. Like a lot of people, she could never really understand why they “didn’t fall down.”

  “Look, Mom,” I’d said, “they’re moving mighty fast, going around the earth in a big circle. And when anything moves like this, you get centrifugal force. It’s just the same when you whirl a stone at the end of a string.”

  “I don’t whirl stones on the end of strings,” said Mom, “and I hope you won’t either, at least not indoors.”

  “I was only giving an example,” I had told her. “It’s the one they always use at school. Just as the stone can’t fly away because of the pull in the string, so a space station has to stay there because of the pull of gravity. Once it’s given the right speed, it’ll stay there forever without using any power. It can’t lose speed because there’s no air resistance. Of course, the speed’s got to be calculated carefully. Near the earth, where gravity’s powerful, a station has to move fast to stay up. It’s like tying your stone on to a short piece of string; you have to whirl it quickly. But a long way out, where gravity’s weaker, the stations can move slowly.”

  “I thought it was something like that,” she replied. “But what worries me is this—suppose one of the stations did lose a bit of speed. Wouldn’t it come falling down? The whole thing looks dangerous to me. It seems a sort of balancing act. If anything goes wrong…”

  I hadn’t known the answer then, so I’d only been able to say: “Well, the moon doesn’t fall down, and it stays up just the same way.” It wasn’t until I’d got to the Inner Station that I learned the answer, though I should have been able to work it out for myself. If the velocity of a space station did drop a bit, it would simply move into a closer orbit. You’d have to carve off quite a lot of its speed before it came dangerously close to earth, and it would take a vast amount of rocket braking to do this. It couldn’t possibly happen by accident.

  Now I looked at the clock. Another thirty minutes to go. Funny—why do I feel so sleepy now? I had a good rest last night. Perhaps the excitement’s been a bit too much. Well, let’s just relax and take things easy—there’s nothing to do until we reach the Inner Station in four hours’ time. Or is it four days? I really can’t remember, but, anyway, it isn’t important. Nothing is important any more, not even the fact that everything around me is half-hidden in a pink mist….

  Then I heard Commander Doyle shouting. He sounded miles away, and though I had an idea that the words he was calling should mean something, I didn’t know what it was. They were still ringing vainly in my ears when I blacked out completely: “Emergency Oxygen!”

  8 INTO THE ABYSS

  It was one of those peculiar dreams when you know you’re dreaming and can’t do anything about it. Everything that had happened to me in the last few weeks was all muddled up together, as well as flash backs from earlier experiences. Sometimes things were quite the wrong way round. I was down on earth, but weightless, floating like a cloud over valleys and hills. Or else I was up in the Inner Station, but had to struggle against gravity with every movement I made.

  The dream ended in nightmare. I was taking a short cut through the Inner Station, using an illegal but widely practiced method that Norman Powell had shown me. Linking the central part of the station with its outlying pressurized chambers are ventilating ducts, wide enough to take a man. The air moves through them at quite a speed, and there are places where one can enter and get a free ride. It’s an exciting experience, and you have to know just what you’re doing or you may miss the exit and have to buck the air stream to find a way back. Well, in this dream I was riding the air stream and had lost my way. There ahead of me I could see the great blades of the ventilating fan, sucking me down toward them. And the protecting grille was gone! In a few seconds I’d be sliced like a side of bacon….

  “He’s all right,” I heard someone say. “He was only out for a minute. Give him another sniff.”

  A jet of cold gas played over my face, and I tried to jerk my head out of the way. Then I opened my eyes and realized where I was.

  “What happened?” I asked, still feeling rather dazed.

  Tim Be
nton was sitting beside me, an oxygen cylinder in his hand. He didn’t look in the least upset.

  “We’re not quite sure,” he said. “But it’s O.K. now. A change-over valve must have jammed in the oxygen supply when one of the tanks got empty. You were the only one who passed out, and we’ve managed to clear the trouble by bashing the oxygen distributor with a hammer. Crude, but it usually works. Of course, it will have to be stripped down when we get back, and someone will have to find out why the alarm didn’t work.”

  I still felt rather muzzy and a little ashamed of myself for fainting, though that wasn’t the kind of thing anyone could help. And, after all, I had acted as a sort of human guinea pig to warn the others. Or perhaps a better analogy would be one of the canaries the old-time miners took with them to test the air underground.

  “Does this sort of thing happen very often?” I asked.

  “Very seldom,” replied Norman Powell. For once he looked serious. “But there are so many gadgets in a spaceship that you’ve always got to keep on your toes. In a hundred years we haven’t got all the bugs out of spaceflight. If it isn’t one thing, it’s another.”

  “Don’t be so glum, Norman,” said Tim. “We’ve had our share of trouble for this trip. It’ll be plain sailing now.”

  As it turned out, that remark was about the most unfortunate that Tim ever made. I’m sure the others never gave him a chance to forget it.

  We were now several miles from the hospital, far enough away to avoid our jet doing any damage to it. The pilot had set his controls and was waiting for the calculated moment to start firing, and everyone else was lying down in his bunk. The acceleration would be too weak to be anything of a strain, but we were supposed to keep out of the pilot’s way at blast-off and there was simply nowhere else to go.

  The motors roared for nearly two minutes. At the end of that time the hospital was a tiny, brilliant toy twenty or thirty miles away. If the pilot had done his job properly, we were now dropping down on a long curve that would take us back to the Inner Station. We had nothing to do but sit and wait for the next three and a half hours, while the earth grew bigger and bigger until it once more filled almost half the sky.

  On the way out, because of our patient we hadn’t been able to talk, but there was nothing to stop us now. There was a curious kind of elation, even lightheadedness, about our little party. If I’d stopped to think about it, I should have realized that there was something odd in the way we were all laughing and joking. At the time, though, it seemed natural enough.

  Even the commander unbent more than I’d ever known him to before—not that he was ever really very formidable, once you’d got used to him. But he never talked about himself, and back at the Inner Station no one would have dreamed of asking him to tell the story of his part in the first expedition to Mercury. And if they had, he certainly wouldn’t have done so—yet he did now. He grumbled for a while, but not very effectively. Then he began to talk.

  “Where shall I start?” he mused. “Well, there’s not much to say about the voyage itself—it was just like any other trip. No one else had ever been so near the sun before, but the mirror-plating of our ship worked perfectly and stopped us getting too hot by bouncing eighty percent of the sun’s rays straight off again.

  “Our instructions were not to attempt a landing unless we were quite sure it would be safe. So we got into an orbit a thousand miles up and began to do a careful survey.

  “You know, of course, that Mercury always keeps one face turned toward the sun, so that it hasn’t days or nights as we have on earth. One side is in perpetual darkness, the other in blazing light. However, there’s a narrow ‘twilight’ zone between the two hemispheres, where the temperature isn’t too extreme. We planned to come down somewhere in this region, if we could find a good landing place.

  “We had our first surprise when we looked at the day side of the planet. Somehow, everyone had always imagined that it would be very much like the moon—covered with jagged craters and mountain ranges. But it wasn’t. There are no mountains at all on the part of Mercury directly facing the sun, only a few low hills and great, cracked plains. When we thought about it, the reason was obvious. The temperature down there in that perpetual sunlight is over seven hundred degrees Fahrenheit. That’s much too low to melt rock, but it can soften it, and gravity had done the rest. Over millions of years, any mountains that might have existed on the day side of Mercury had slowly collapsed, just as a block of pitch flows on a hot day. Only round the rim of the night land, where the temperature was far lower, were there any real mountains.

  “Our second surprise was to discover that there were lakes down in that blazing inferno. Of course, they weren’t lakes of water, but of molten metal. Since no one has been able to reach them yet, we don’t know what metals they are—probably lead and tin, with other things mixed up with them. Lakes of solder, in fact! They may be pretty valuable one day, if we can discover how to tap them.”

  The commander nodded his head thoughtfully, before continuing.

  “As you’ll guess from this, we weren’t anxious to land anywhere in the middle of the day side. So when we’d completed a photographic map we had a look at the night land.

  “The only way we could do that was to illuminate it with flares. We went as close as we dared, less than a hundred miles up, and shot off billion candle power markers one after another, taking photographs as we did so. The flares, of course, shared our speed and traveled along with us until they burned out.

  “It was a strange experience, knowing that we were shedding light on a land that had never seen the sun—a land where the only light for maybe millions of years had been that of the stars. If there was any life down there—which seemed about as unlikely as anything could be—it must be having quite a surprise! At least, that was my first thought as I watched our flares blasting that hidden land with their brilliance. Then I decided that any creatures of the night land would probably be completely blind, like the fish of our own ocean depths. Still, all this was fantasy. Nothing could possibly live down there in that perpetual darkness, at a temperature of almost four hundred degrees below freezing point. We know better, now, of course.” He smiled.

  “It was nearly a week before we risked a landing, and by that time we’d mapped the surface of the planet pretty thoroughly. The night land, and much of the twilight zone, is fairly mountainous, but there were plenty of flat regions that looked promising. We finally chose a large, shallow bowl on the edge of the day side.

  “There’s a trace of atmosphere on Mercury, but not enough for wings or parachutes to be of any use. So we had to land by rocket braking, just as you do on the moon. However often you do it, a rocket touchdown is always a bit unnerving, especially on a new world where you can’t be perfectly sure that what looks like rock is anything of the sort.

  “Well, it was rock, not one of those treacherous dust-drifts they have on the moon. The landing gear took up the impact so thoroughly that we hardly noticed it in the cabin. Then the motors cut out automatically and we were down, the first men to land on Mercury. The first living creatures, probably, ever to touch the planet.

  “I said that we’d come down at the frontiers of the day side. That meant that the sun was a great, blinding disk right on the horizon. It was strange, seeing it almost fixed there, never rising or setting though, because Mercury has a very eccentric orbit, the sun does wobble to and fro through a considerable arc in the sky. Still, it never dropped below the horizon, and I always had the feeling that it was late afternoon and that night would fall shortly. It was hard to realize that ‘night’ and ‘day’ didn’t mean anything here….

  “Exploring a new world sounds exciting, and so it is, I suppose. But it’s also hard work—and dangerous, especially on a planet like Mercury. Our first job was to see that the ship couldn’t get overheated, and we’d brought along some protective awnings for this purpose. Our ‘sunshades,’ we called them. They looked peculiar, but they did the job properly. We e
ven had portable ones, like flimsy tents, to protect us if we stayed out in the open for any length of time. They were made of white nylon and reflected most of the sunlight, though they let through enough to provide all the warmth and light we wanted.

  “We spent several weeks reconnoitering the day side, traveling up to twenty miles from the ship. That may not sound very far, but it’s quite a distance when you’ve got to wear a space suit and carry all your supplies. We collected hundreds of mineral specimens and took thousands of readings with our instruments, sending back all the results we could by tight-beam radio to earth. It was impossible to go far enough into the day side to reach the lakes we’d seen. The nearest was over eight hundred miles away, and we couldn’t afford the rocket fuel to go hopping around the planet. In any case, it would have been far too dangerous to go into that blazing furnace with our present, untried equipment.”

  The commander paused, staring thoughtfully into space as if he could see beyond our cramped little cabin to the burning deserts of that distant world.

  “Yes,” he continued at last, “Mercury’s quite a challenge. We can deal with cold easily enough, but heat’s another problem. I suppose I shouldn’t say that, because it was the cold that got me, not the heat….

  “The one thing we never expected to find on Mercury was life, though the moon should have taught us a lesson. No one had expected to find it there, either. And if anyone had said to me, ‘Assuming that there is life on Mercury, where would you hope to find it?’ I’d have replied, “Why, in the twilight zone, of course.’ I’d have been wrong again.