“Only for a brief moment in history was it of direct concern to mankind. And yet, if it had never existed, we would not be here! In one sense, therefore, it was of vital importance even to pretechnological humanity, right back to the first ape man—indeed, right back to the first living creatures on this planet. For the ionosphere is part of the shield that protects us from the sun’s deadly X-ray and ultraviolet radiations. If they had penetrated to sea level, perhaps some kind of life might still have arisen on earth; but it would never have evolved into anything remotely resembling us.
“. . . Because the ionosphere, like the atmosphere below it, is ultimately controlled by the sun, it, too, has its weather. During times of solar disturbance, it is blasted by planet-wide gales of charged particles, and twisted into loops and whirls by the Earth’s magnetic field. On such occasions, it is no longer invisible. It reveals itself in the glowing curtains of the aurora—one of Nature’s most awesome spectacles, illuminating the cold polar nights with its eerie radiance. . . .
“Even now, we do not understand all the processes occurring in the ionosphere. One reason why it has proved difficult to study is that all our rocket and satellite-borne instruments race through it at thousands of kilometers an hour. We have never been able to stand still to make observations. Now, for the first time, the construction of the proposed Orbital Tower gives us a chance of establishing fixed observatories in the ionosphere. It is also possible that the Tower may itself modify the characteristics of the ionosphere—though it will certainly not, as Dr. Bickerstaff has suggested, short-circuit it!
“Why should we study this region, now that it is no longer important to the communications engineers? Well, apart from its beauty, its strangeness, and its scientific interest, its behavior is closely linked with that of the sun—the master of our destiny. We know now that the sun is not the steady, well-behaved star that our ancestors believed. It undergoes both long- and short-period fluctuations. At the present time it is still emerging from the so-called Maunder Minimum of 1645 to 1715. As a result, the climate now is milder than at any time since the early Middle Ages. But how long will this upswing last? Even more important, when will the inevitable downturn begin, and what effect will this have upon climate, weather, and every aspect of human civilization—not only on this planet, but on the others as well? For they are all children of the sun. . . .
“Some very speculative theories suggest that the sun is now entering a period of instability, which may produce a new Ice Age, more universal than any in the past. If this is true, we need every scrap of information we can get to prepare for it. Even a century’s warning might not be long enough. . . .
“The ionosphere helped to create us; it launched the communications revolution; it may yet determine much of our future. That is why we must continue the study of this vast, turbulent arena of solar and electric forces—this mysterious place of silent storms.”
39
The Wounded Sun
The last time Morgan had seen Dev, his nephew had been a child. Now he was a boy in his early teens; and at their next meeting, at this rate, he would be a man.
The engineer felt only a mild sense of guilt. Family ties had been weakening for the last two centuries. He and his sister had little in common except the accident of genetics. Though they exchanged greetings and small talk perhaps half a dozen times a year, and were on the best of terms, he was not even sure when and where they had last met.
Yet when he greeted the eager, intelligent boy (not in the least overawed, it seemed, by his famous uncle), Morgan was aware of a certain bittersweet wistfulness. He had no son to continue the family name. Long ago, he had made that choice between work and life that can seldom be avoided at the highest levels of human endeavor. On three occasions—not including the liaison with Ingrid—he might have taken a different path, but accident or ambition had deflected him.
He knew the terms of the bargain he had made and he accepted them; it was too late now to grumble about the small print. Any fool could shuffle genes and most did. But whether or not history gave him credit, few men could have achieved what he had done—and was about to do.
In the last three hours, Dev had seen far more of Earth Terminal than any of the usual run of VIPs. He had entered the mountain at ground level, along the almost completed approach to South Station, and had been given the quick tour of the passenger and baggage-handling facilities, the control center, and the switching yard, where capsules would be routed from the east and west Down tracks to the north and south Up ones. He had stared up the five-kilometer-long shaft—like a giant gun barrel aimed at the stars, as several hundred reporters had already remarked in hushed voices—along which the lines of traffic would rise and descend. And his questions had exhausted three guides before the last one had thankfully handed him over to his uncle.
“Here he is, Van,” said Warren Kingsley as they arrived via the high-speed elevator at the truncated summit of the mountain. “Take him away before he grabs my job.”
“I didn’t know you were so keen on engineering, Dev.”
The boy looked hurt, and a little surprised.
“Don’t you remember, Uncle, that Number 12 Meccamax set you gave me on my tenth birthday?”
“Of course, of course. I was only joking.” And, to tell the truth, he had not really forgotten the construction set; it had merely slipped his mind for the moment. . . . “You’re not cold up here?” Unlike the well-protected adults, the boy had disdained the usual light thermocoat.
“No, I’m fine. What kind of jet is that? When are you going to open the shaft? Can I touch the tapes?”
“See what I mean?” Kingsley chuckled.
“One: that’s Sheik Abdullah’s Special; his son Feisal is visiting. Two: we’ll keep this lid on until the Tower reaches the mountain and enters the shaft. We need it as a working platform, and it keeps out the rain. Three: you can touch the tapes if you want to. Don’t run—it’s bad for you at this altitude!”
“If you’re thirteen, I doubt it,” said Kingsley, looking at Dev’s rapidly receding back. Taking their time, they caught up with him at the East anchor.
The boy was staring, as so many thousands of others had already done, at the narrow band of dull gray that rose straight out of the ground and soared vertically into the sky. Dev’s gaze followed it up, up, up, until his head was tilted as far back as it would go. Morgan and Kingsley did not follow suit, though the temptation, after all these years, was still strong. Nor did they warn him that some visitors got so giddy that they collapsed and were unable to walk away without assistance.
The boy was tough: he gazed intently at the zenith for almost a minute, as if hoping to see the thousands of men and millions of tons of material poised there beyond the deep blue of the sky. Then he closed his eyes with a grimace, shook his head, and looked down at his feet for an instant, as if to reassure himself that he was still on the solid, dependable Earth.
He reached out a cautious hand and stroked the narrow ribbon linking the planet with its new moon.
“What would happen,” he asked, “if it broke?”
That was an old question. Most people were surprised at the answer.
“Very little. At this point, it’s under practically no tension. If you cut the tape, it would just hang there, waving in the breeze.”
Kingsley made an expression of distaste; both knew that this was a considerable oversimplification. At the moment, each of the four tapes was stressed at about a hundred tons, but that was negligible compared to the design loads they would be handling when the system was in operation and they had been integrated into the structure of the Tower. There was no point, however, in confusing the boy with such details.
Dev thought this over. Then he gave the tape an experimental flick, as if he hoped to extract a musical note from it. But the only response was an unimpressive “click” that instantly died away.
“If you hit it with a sledge hammer,” said Morgan, “and came back about ten
hours later, you’d be just in time for the echo from Midway.”
“Not any longer,” said Kingsley. “Too much damping in the system.”
“Don’t be a spoilsport, Warren. Now come and see something really interesting.”
They walked to the center of the circular metal disk that now capped the mountain and sealed the shaft like a giant saucepan lid. Here, equidistant from the four tapes down which the Tower was being guided earthward, was a small geodesic hut, looking even more temporary than the surface on which it had been erected. It housed an oddly designed telescope, which pointed straight upward and was apparently incapable of being aimed in any other direction.
“This is the best time for viewing, just before sunset. The base of the Tower is nicely lit up then.”
“Talking of the sun,” said Kingsley, “just look at it now. It’s even clearer than yesterday.” There was something approaching awe in his voice as he pointed at the brilliant flattened ellipse sinking down into the western haze. The horizon mists had dimmed its glare so much that one could stare at it in comfort.
Not for more than a century had such a group of spots appeared. They stretched across almost half the golden disk, making it seem as if the sun had been stricken by some malignant disease or pierced by falling worlds. Yet not even mighty Jupiter could have created such a wound in the solar atmosphere. The largest spot was a quarter of a million kilometers across, and could have swallowed a hundred Earths.
“There’s another big auroral display predicted for tonight. Professor Sessui and his merry men certainly timed it well.”
“Let’s see how they’re getting on,” said Morgan as he made some adjustments to the eyepiece. “Have a look, Dev.”
The boy peered intently for a moment. “I can see the four tapes, going inward—I mean upward—until they disappear.”
“Nothing in the middle?”
Another pause.
“No—not a sign of the Tower.”
“Correct. It’s still six hundred kilometers up, and we’re on the lowest power of the telescope. Now I’m going to zoom. Fasten your seat belt.”
Dev gave a little laugh at the ancient cliché, familiar from dozens of historical dramas. At first he could see no alteration, except that the four lines pointing toward the center of the field were becoming a little less sharp. It took him a few seconds to realize that no change could be expected as his point of view hurtled upward along the axis of the system; the quartet of tapes would look exactly the same at any point along its length.
Then, quite suddenly, it was there, taking him by surprise even though he had been expecting it. A tiny bright spot had materialized in the exact center of the field. It was expanding as he watched it, and now for the first time he had a real sensation of speed.
A few seconds later, he could make out a small circle—no, now both brain and eye agreed that it was a square. He was looking directly up at the base of the Tower, crawling Earthward along its guiding tapes at a couple of kilometers a day. The four tapes had now vanished, being far too small to be visible at this distance. But that square fixed magically in the sky continued to grow, though now it had become fuzzy under the extreme magnification.
“What do you see?” asked Morgan.
“A bright little square.”
“Good. That’s the underside of the Tower, still in full sunlight. When it’s dark down here, you can see it with the naked eye for another hour before it enters the Earth’s shadow. Now, do you see anything else?”
“Nooo . . .” replied the boy, after a long pause.
“You should. There’s a team of scientists visiting the lowest section to set up some research equipment. They’ve just come down from Midway. If you look carefully, you’ll see their transporter. It’s on the south track—that will be the right side of the picture. Look for a bright spot, about a quarter the size of the Tower.”
“Sorry, Uncle, I can’t find it. You have a look.”
“Well, the seeing may have got worse. Sometimes the Tower disappears completely though the atmosphere may look—”
Before Morgan could take Dev’s place at the eyepiece, his personal receiver gave two shrill double bleeps. A second later, Kingsley’s alarm also erupted.
It was the first time the Tower had ever issued a four-star emergency alert.
40
The End of the Line
No wonder they called it the Trans-Siberian Railroad. Even on the easy downhill run, the journey from Midway Station to the base of the Tower lasted fifty hours.
One day it would take only five, but that lay two years in the future, when the tracks were energized and their magnetic fields activated. The inspection and maintenance vehicles that now ran up and down the faces of the Tower were propelled by old-fashioned tires gripping the interior of guidance slots. Even if the limited power of the batteries permitted, it was not safe to operate such a system at more than five hundred kilometers an hour.
Yet everyone had been far too busy to be bored. Professor Sessui and his three students had been observing, checking their instruments, and making sure that no time would be wasted when they transferred into the Tower. The capsule driver, his engineering assistant, and the one steward, who made up the entire cabin staff, were also fully occupied, because this was no routine trip. The “Basement,” twenty-five thousand kilometers below Midway—and now only six hundred kilometers from Earth—had never been visited since it was built. Until now, there had been no purpose in going there, since the handful of monitors had never reported anything amiss. Not that there was much to go wrong, because the Basement was merely a fifteen-meter square pressurized chamber—one of the scores of emergency refuges at intervals along the Tower.
Sessui had used all his considerable influence to borrow this unique site, now crawling down through the ionosphere at two kilometers a day toward its rendezvous with Earth. It was essential, he had argued forcibly, to get his equipment installed before the peak of the current sunspot maximum.
Already, solar activity had reached unprecedented levels, and Sessui’s young assistants often found it hard to concentrate on their instruments; the magnificent auroral displays outside were too much of a distraction. For hours on end, both northern and southern hemispheres were filled with slowly moving curtains and streamers of greenish light, beautiful and awe-inspiring—yet only a pale ghost of the celestial firework displays taking place around the poles. It was rare for the aurora to wander so far from its normal domains: only once in generations did it invade the equatorial skies.
Sessui had driven his students back to work with the admonition that they would have plenty of time for sightseeing during the long climb back to Midway. Yet it was noticeable that even the Professor himself sometimes stood at the observation window for minutes at a time, entranced by the spectacle of the burning heavens.
Someone had christened the project Expedition to Earth—which, as far as distance was concerned, was ninety-eight percent accurate. As the capsule crawled down the face of the Tower at its miserable five hundred klicks, the increasing closeness of the planet beneath made itself obvious. Gravity was slowly increasing, from the delightful less-than-lunar buoyancy of Midway to almost its full terrestrial value. To any experienced space traveler, this was strange indeed: to feel any gravity before the moment of atmospheric entry seemed a reversal of the normal order of things.
Apart from complaints about the food, stoically endured by the overworked steward, the journey had been devoid of incident. A hundred kilometers from the Basement, the brakes had been gently applied and speed had been halved. It was halved again at fifty kilometers; as one of the students remarked: “Wouldn’t it be embarrassing if we ran off the end of the track?”
The driver—who insisted on being called pilot—retorted that this was impossible, because the guidance slots down which the capsule was falling terminated several meters short of the Tower’s end, and there was also an elaborate buffer system, just in case all four independent sets o
f brakes failed to work.
And everyone agreed that the joke, besides being perfectly ridiculous, was in extremely poor taste.
41
Meteor
The vast artificial lake known for two thousand years as the Sea of Paravana lay calm and peaceful beneath the stone gaze of its builder. Though few now visited the lonely statue of Kalidasa’s father, his work, if not his fame, had outlasted that of his son; and it had served his country infinitely better, bringing food and drink to a hundred generations of men.
And to many more generations of birds, deer, buffalo, monkeys, and their predators, like the sleek and well-fed leopard now drinking at the water’s edge. The big cats were becoming rather too common, and were inclined to be a nuisance now that they no longer had anything to fear from hunters. But they never attacked men unless they were cornered or molested.
Confident of his security, the leopard was leisurely drinking his fill as the shadows around the lake lengthened and twilight advanced from the east. Suddenly, he pricked up his ears, instantly alert; but no mere human senses could have detected any change in land, water, or sky. The evening was as tranquil as ever.
Then, directly out of the zenith, came a faint whistling that grew steadily to a rumbling roar, with tearing, ripping undertones, quite unlike that of a reentering spacecraft. Up in the sky, something metallic was sparking in the last rays of the sun, growing larger and leaving a trail of smoke behind it.
As it expanded, it disintegrated. Pieces shot off in all directions, some of them burning as they did so. For a few seconds, an eye as keen as the leopard’s might have glimpsed a roughly cylindrical object, before it exploded into a myriad fragments. But the leopard did not wait for the final catastrophe; it had already disappeared into the jungle.
The Sea of Paravana erupted in thunder. A geyser of mud and spray shot a hundred meters into the air—a fountain far surpassing those of Yakkagala, and one almost as high as the Rock itself. It hung suspended for a moment in futile defiance of gravity before tumbling back into the shattered lake.