Vectors

by Charles Sheffield

  "I heard what you said to Panosky, but it still seems to me that the robots ought to be useful."

  "I'd hoped so, too. I checked again with Jen, and he agrees we'd have to reprogram them, and we don't have the time for it. It would take weeks. Jen said having them around would be like taking along a half-trained dog, bumbling about while we work. Forget that one."

  As we talked, we kept our eyes open for the outbound buckets, passing us on the other side of the Beanstalk. We were only about ten meters from them at closest approach and they seemed to hurtle past us at an impossible speed. The idea of hitching on to one of them began to seem more and more preposterous. We settled down to look in more detail at the configuration of cables, drive train, repair stations and buckets that was being flashed to us over the suit videos.

  It was a weary time, an awful combination of boredom and tension. The video images were good, but there is a limit to what you can learn from diagrams and simulations. About once an hour, Jen Hasse and Larry Marston called in from the lower bucket beneath us, reporting on the news—or lack of it—regarding the bomb detection efforts. A message relayed from Panosky at Tether Control reported no progress in negotiations with the terrorists. The fanatics simply didn't believe their terms couldn't be met. That was proof of their naivety, but didn't make them any less dangerous.

  It was impossible to get comfortable in our suits. The ore buckets had never been designed for a human occupant, and we couldn't find a level spot to stretch out. Alicia and I passed into a half-awake trance, still watching the images that flashed onto the suit videos, but not taking in much of anything. Given that we couldn't sleep, we were probably in the closest thing we could get to a resting state. I hoped that Jen and Larry would keep their attention up, watching an endless succession of buckets flash past them and checking each one for radioactivity count.

  The break came after fifty-four hours in the bucket. We didn't need to hear the details from the carrier below us to know they had it—Larry's voice crackled with excitement.

  "Got it," he said. "Jen picked up a strong signal from the bucket we just passed. If you leave the ore carrier within thirty-four seconds, you'll have thirty-eight minutes to get ready for it to come past you. It will be the second one to reach you. For God's sake don't try for the wrong one."

  There was a pause, then Larry said something I would never have expected from him. "We'll lose radio contact with you in a while, as we move further along the Stalk. Good luck, both of you—and look after him, Alicia."

  I didn't have time to think that one through—but shouldn't he be telling me to look after her? It was no time for puzzling. We were up on top of our bucket in a second, adrenalin moving through our veins like an electric current. The cable was whipping past us at a great rate; the idea of forsaking the relative safety of the ore bucket for the naked wall of the Beanstalk seemed like insanity. We watched as one of the repair stations, sticking out from the cable into open space, flashed past.

  "There'll be another one of those coming by in thirty-five seconds," I said. "We've got to get the grapnels onto it, and we'll be casting blind. I'll throw first, and you follow a second later. Don't panic if I miss—remember, we only have to get one good hook there."

  "Count us down, Jack," said Alicia. She wasn't one to waste words in a tight spot.

  I pressed the digital read-out in my suit, and watched the count move from thirty-five down to zero.

  "Count-down display on Channel Six," I said, and picked up the rope and grapnel. I looked doubtfully at the wheel that was set in the middle of the thin rope, then even looked suspiciously at the rope itself, wondering if it would take the strain. That shows how the brain works in a crisis—that rope would have held a herd of elephants with no trouble at all.

  I cast the grapnel as the count touched to zero, and Alicia threw a fraction later. Both ropes were spliced onto both suits, so it was never clear which grapnel took hold. Our bucket continued to drop rapidly towards Earth, but we were jerked off the top of it and went zipping on downwards fractionally slower as the friction reel in the middle of the rope unwound, slowing our motion.

  We came to a halt about fifty meters down the Beanstalk from the grapnel, after a rough ride in which our deceleration must have averaged over seven gee. Without that reel to slow us down gradually, the jerk of the grapnel as it caught the repair station wall would have snapped our spines when we were lifted from the ore bucket.

  We hung there, swinging free, suspended from the wall of the Stalk. As the reel began to take up the line that had been paid out, I made the mistake of looking down. We dangled over an awful void, with nothing between us and that vast drop to the Earth below but the thin line above us. When we came closer to the point of attachment to the Beanstalk wall, I saw just how lucky we had been. One grapnel had missed completely, and the second one had caught the very lip of the repair station platform. Another foot to the left and we would have missed it altogether.

  We clawed our way up to the station rim—easy enough to do, because the gravity at that height was only a fraction of a gee, less than a tenth. But a fall from there would be inexorable, and we would have fallen away from the Beanstalk, with no chance to reconnect to it. Working together, we freed the grapnel and readied both lines and grapnels for re-use. After that there was nothing to do but cling to the side of the Beanstalk, watch the sweep of the heavens above us, and wait for the outbound ore buckets to come past us.

  The first one came by after seventeen minutes. I had the clock read-out to prove it, otherwise I would have solemnly sworn that we had waited there for more than an hour, holding to our precarious perch. Alicia seemed more at home there than I was. I watched her moving the grapnel to the best position for casting it, then settle down patiently to wait.

  It is hard to describe my own feelings in that period. I watched the movement of the stars above us, in their great circle, and wondered if we would be alive in another twenty minutes. I felt a strong communion with the old sailors of Earth's seas, up in their crow's-nest in a howling gale, sensing nothing but darkness, high-blown spindrift, perilous breakers ahead, and the dipping, rolling stars above.

  Alicia kept her gaze steadily downwards, something that I found hard to do. She had inherited a good head for heights from her circus-performer grandmother.

  "I can see it," she said at last. "All ready for a repeat performance?"

  "Right." I swung the grapnel experimentally. "Since we can see it this time, we may as well throw together."

  I concentrated on the bucket sweeping steadily up towards us, trying to estimate the distance and the time that it would take before it reached us. We both drew back our arms at the same moment and lobbed the grapnels towards the center of the bucket.

  It came past us with a monstrous, silent rush. Again we felt the fierce acceleration as we were jerked away from the Beanstalk wall and shot upwards after the carrier. Again, I realized that we couldn't have done it without Alicia's friction reel, smoothing the motion for us. This time, it was more dangerous than when we had left the downbound bucket. Instead of trying to reach the stationary wall of the Stalk, we were now hooked onto the moving bucket. We swung wildly beneath it in its upward flight, narrowly missing contact with elements of the drive train, and then with another repair station that flashed past a couple of meters to our right.

  Finally, somehow, we damped our motion, reeled in the line, slid back the cover to the ore bucket and fell safely forward inside it. I was completely drained. It must have been all nervous stress—we hadn't expended a significant amount of physical energy. I know that Alicia felt the same way as I did, because after we plumped over the rim of the carrier we both fell to the floor and lay there without speaking for several minutes. It gives some idea of our state of mind when I say that the bucket we had reached, with a four megaton bomb inside it that might go off at any moment, seemed like a haven of safety.

  We finally found the energy to get up and look around us. The bucket w
as loaded with manufactured goods, and I thought for a sickening moment that the bomb was not there. We found it after five minutes of frantic searching. It was a compact blue cylinder, a meter long and fifty centimeters wide, and it had been cold-welded to the wall of the bucket. I knew the design.

  "There it is," I said to Alicia. Then I didn't know what to say next. It was the most advanced design, not the big, old one that I had been hoping for.

  "Can you disarm it?" asked Alicia.

  "In principle. There's only one problem. I know how it's put together—but I'll never be able to get it apart wearing a suit. The fingerwork I'd need is just too fine for gloves. We seem to be no better off than we were before."

  We sat there side by side, looking at the bomb. The irony of the situation was sinking in. We had reached it, just as we hoped we could. Now, it seemed we might as well have been still back in the station.

  "Any chance that we could get it free and dump it overboard?" asked Alicia. "You know, just chuck the thing away from the bucket."

  I shook my head, aware again of how much my suit impeded freedom of movement. "It's spot-welded. We couldn't shift it. Anyway, free fall from here would give it an impact orbit, and a lot of people might be killed if it went off inside the atmosphere. If we were five thousand kilometers higher, perigee would be at a safe height above the surface—but we can't afford to wait for another sixteen hours until the bucket gets up that high. Look, I've got another idea, but it will mean that we'll lose radio contact with the station."

  "So what?" said Alicia. Her voice was weary. "There's not a thing they can do to help us anyway."

  "They'll go out of their minds with worry down on Earth, if they don't know what's happening here."

  "I don't see why we should keep all of it for ourselves. What's your idea, Jack?"

  "All right." I summoned my reserves of energy. "We're in vacuum now, but this bucket would be airtight if we were to close the top hatch again. I have enough air in my suit to make a breathable atmosphere in this enclosed space, at least for long enough to let me have a go at the bomb. We've got nearly twelve hours to the deadline, and if I can't disarm it in that time I can't do it at all."

  Alicia looked at her air reserve indicator and nodded. "I can spare you some air, too, if I open up my suit."

  "No. We daren't do that. We have one other big problem—the temperature. It's going to feel really cold in here, once I'm outside my suit. I'll put my heaters on to maximum, and leave the suit open, but I'm still not sure I can get much done before I begin to freeze up. If I begin to lose feeling in my fingers, I'll need your help to get me back inside. So you have to stay in your suit. Once I'm warmed up, I can try again."

  She was silent for a few moments, repeating the calculations that I had just done myself.

  "You'll only have enough air to try it twice," she said at last. "If you can't do it in one shot, you'll have to let me have a go. You can direct me on what has to be done."

  There was no point in hanging around. We sent a brief message to the station, telling them what we were going to do, then closed the hatch and began to bleed air out of my suit and into the interior of the bucket. We used the light from Alicia's suit, which had ample power to last for several days.

  When the air pressure inside the bucket was high enough for me to breathe, I peeled out of my suit. It was as cold as charity in that metal box, but I ignored that and crouched down alongside the bomb in my underwear and bare feet.

  I had eleven hours at the most. Inside my head, I fancied that I could hear a clock ticking. That must have been only my fancy. Modern bombs have no place for clockwork timers.

  By placing my suit directly beneath my hands, I found that I could get enough heat from the thermal units to let me keep on working without a break. The clock inside my head went on ticking, also without a break.

  On and on and on.

  * * *

  They say that I was delirious when we reached the station. That's the only way the Press could reconcile my status as public hero with the things that I said to the President when he called up to congratulate us.

  I suppose I could claim delirium if I wanted to—five days without sleep, two without food, oxygen starvation, and frostbite of the toes and ears, that might add up to delirium. I had received enough warmth from the suit to keep my hands going, because it was very close to them, but that had been at the expense of some of my other extremities. If it hadn't been for Alicia, cramming me somehow back into the suit after I had disarmed the bomb, I would have frozen to death in a couple of hours.

  As it was, I smelled ripe and revolting when they unpacked us from the bucket and winkled me out of my suit—Alicia hadn't been able to re-connect me with the plumbing arrangements.

  So I told the President that the World Congress was composed of a giggling bunch of witless turds, who couldn't sense a global need for more bridges to space if a Beanstalk were pushed up their backsides—which was where I thought they kept their brains. Not quite the speech that we used to get from the old-time returning astronauts, but I must admit it's one that I'd wanted to give for some time. The audience was there this time, with the whole world hanging on my words over live TV.

  We've finally started construction on the second Beanstalk. I don't know if my words had anything to do with it, but there was a lot of public pressure after I said my piece, and I like to think that I had some effect.

  And me? I'm designing the third Beanstalk; what else? But I don't think I'll hold my breath waiting for a Congressional Vote of Thanks for my efforts saving the first one.

  Afterword.

  A good science fiction short story, running twenty pages or less, is hard to write—harder than other short stories. In addition to the plot, characters, and general background, the writer must somehow work in the scientific background that makes the story science fiction. If the main idea is scientifically new and complex, that alone will take up all twenty pages, just to explain it.

  What you usually find is a trade-off. As the original science content of the story goes up, the intensity, depth of characterization and plot content go down. Twenty pages are twenty pages, and although a skilled writer may be able to compress a quart into a pint pot, ten gallons won't fit in there. No amount of compression can give a short story the same freedom for development as a novel.

  There are three traditional solutions to this problem. One is to write stories that have no science content at all. This leaves maximum scope for the other goodies. Lots of people use this approach, but to me the result is not science fiction.

  Another solution is to use old concepts that readers have met before, but to do it so that an impression of something new is transferred to the reader. No one has to go into details any more about what a rocket is or does—that was not true a hundred years ago. We don't choke over the idea of a low-gee environment, and I can write the words "warp drive" and know that the average reader won't even be slowed by it. I believe that most short sf falls into this category, of the use of the familiar trappings of the field.

  Finally, the third method is to bite the bullet, accept the trade-off, and admit that short stories with complex new ideas will be stories mainly about those ideas. That's what I did in "Skystalk." Although the work is fiction, the idea is the story. For character, look elsewhere in this collection.

  HOW TO BUILD A BEANSTALK

  THE AGE OF ROCKETS.

  The launch of a Saturn V rocket is an impressive sight. It is impressively noisy, impressively big and impressively risky. It is also one of Man's outstanding examples of conspicuous consumption, where a few thousand tons of fuel go up (literally) in smoke (literally) in a couple of minutes. And yet it is, in 1979, the best space transportation system that we have.

  If we were to sit down and make a list of the properties of our 'ideal' space transportation system, without worrying about whether or not we could ever hope to achieve it, what would it look like? Well, first and most important it ought not to use u
p any raw materials in its working—no reaction mass, which all rockets need to propel themselves. It ought to allow us to take materials up and down from planetary surfaces, and be equally good at moving us around in free space. And it would be nice if it were somehow completely energy-free. While we are at it, let's ask that it be also silent and non-polluting.

  Note that our old friend, the rocket, satisfies none of our ideal system requirements. The Space Shuttle, our first reusable spacecraft, is not suited to anything beyond low earth orbit activities, and is, with all its advantages over its non-reusable predecessors, still a very primitive system.

  It may sound improbable, but an ideal space system, satisfying all our requirements, could be here in a couple of generations. As we shall see, the technology needed is not far from that already available to us.

  It is curious that science fiction, which likes to look beyond today's technology, has remained so infatuated with the idea of rockets. Some people even use them to define the field. Look at the 'sf' section in public libraries and you will often see a small drawing of a rocket attached to the spine of each volume. It may be a perverse choice of label for a branch of writing that covers everything from 'Ringworld' to 'Flowers for Algernon,' but you can see how the logic goes; science fiction means space travel, and space travel means rockets—because they are 'the only way of getting up to space and around in space.' After all, there is nothing for any other sort of transportation to 'push against' in space. Right?

  Not quite. We will try and dispose of that peculiar viewpoint here. Our preoccupation with rockets for space travel will probably amaze our descendants.

  "Why use something as wasteful and noisy as a rocket," they will ask, "when there are simple, clean, efficient alternatives? Why didn't they use Beanstalks?"

  The Age of Rockets may look to them like the Age of Dinosaurs. Let's try and see it through their eyes, beginning with the most basic principles.