At once, the sky was full of waterfowl wheeling in startled flight. Almost as numerous, flapping among them like leathery pterodactyls who had somehow survived into the modern age, were the big fruit bats who normally took to the air only after dusk. Equally terrified, birds and bats shared the sky.
The last echoes of the crash died away into the encircling jungle, and silence swiftly returned to the lake. But long minutes passed before its mirror surface was restored and little waves ceased to scurry back and forth beneath the unseeing eyes of Paravana the Great.
42
Death in Orbit
Every large building, it is said, claims a life; fourteen names were engraved on the piers of the Gibraltar Bridge. But thanks to an almost fanatical safety campaign, casualties on the Tower had been remarkably low. There had even been one year without a single death.
And there had been one year with four—two of them particularly harrowing. A space-station assembly supervisor, accustomed to working under zero gravity, had forgotten that though he was in space he was not in orbit, and a lifetime’s experience had betrayed him. He had plummeted more than fifteen thousand kilometers, to burn up like a meteor upon entry into the atmosphere. Unfortunately, his suit radio had remained switched on during those last few minutes. . . .
It was a bad year for the Tower; the second tragedy had been much more protracted, and equally public. An engineer on the counterweight, far beyond synchronous orbit, had failed to fasten her safety belt properly, and had been flicked off into space like a stone from a sling.
She was in no danger, at that altitude, of either falling back to Earth or being launched on an escape trajectory. Unfortunately, her suit held less than two hours’ air. There was no possibility of rescue at such short notice; and despite a public outcry, no attempt was made.
The victim had co-operated nobly. She had transmitted her farewell messages, and then, with thirty minutes of oxygen still unused, opened her suit to vacuum. The body was recovered a few days later, where the inexorable laws of celestial mechanics brought it back to the perigee of its long ellipse.
These tragedies flashed through Morgan’s mind as he took the high-speed elevator down to the operations room, closely followed by a somber Kingsley and the now almost forgotten Dev. But this catastrophe was of an altogether different type, involving an explosion at or near the Basement of the Tower. That the transporter had fallen to Earth was obvious, even before the garbled report was received of a “giant meteor shower” somewhere in central Taprobane.
It was useless to speculate, Morgan thought, until he had more facts; and in this case, where all the evidence had been destroyed, they might never be available. He knew that space accidents seldom had a single cause. They were usually the result of a chain of events, often quite harmless in themselves. All the foresight of the safety engineers could not guarantee absolute reliability, and sometimes their own over-elaborate precautions contributed to disaster.
Morgan was not ashamed of the fact that the safety of the project now concerned him far more than any loss of life. Nothing could be done about the dead; one could only ensure that the same accident would never happen again. But that the almost completed Tower might be endangered was a prospect too appalling to contemplate.
The elevator floated to a halt, and he stepped out into the operations room—just in time for the evening’s second stunning surprise.
43
Fail-Safe
Five kilometers from the terminus, Driver-Pilot Rupert Chang had reduced speed again. Now, for the first time, the passengers could see the face of the Tower as something more than a featureless blur dwindling away to infinity in both directions. Upward, it was true, the twin grooves along which they were riding still stretched forever—or at least for twenty-five thousand kilometers, which on the human scale was much the same. But downward, the end was already in sight. The truncated base of the Tower was clearly silhouetted against the verdant green background of Taprobane, which it would reach and unite with in little more than a year.
Across the display panel, the red ALARM symbols flashed again. Chang studied them with a frown of annoyance and pressed the RESET button. They flickered once, then vanished.
The first time this happened, two hundred kilometers higher, there had been a hasty consultation with Midway Control. A quick check of all systems had revealed nothing amiss; indeed, if all the warnings were to be believed, the transporter’s passengers were already dead. Everything had gone outside the limits of tolerance.
It was obviously a fault in the alarm circuits themselves, and Professor Sessui’s explanation was accepted with general relief. The vehicle was no longer in the pure vacuum environment for which it had been designed. The ionospheric turmoil it had now entered must be triggering the sensitive detectors of the warning systems.
“Someone should have thought of that,” Chang had grumbled. But with less than an hour to go, he was not really worried. He would make constant manual checks of all the critical instrument readings. Midway approved, and in any case there was no alternative.
Battery condition was, perhaps, the item that concerned him most. The nearest charging point was two thousand kilometers higher, and if they couldn’t climb back to that they would be in trouble. But he was quite happy on this score; during the braking process, the transporter’s drive motors had been functioning as dynamos, and ninety percent of its gravitational energy had been pumped back into the batteries. Now that they were fully charged, the surplus hundreds of kilowatts still being generated should be diverted into space through the big cooling fins at the rear.
Those fins, as Chang’s colleagues had often pointed out to him, made his unique vehicle look rather like an old-time aerial bomb. By this time, at the end of the braking process, they should have been glowing a dull red. Chang would have been very worried had he known that they were still comfortably cool. Energy can never be destroyed; it has to go somewhere. And often it goes to the wrong place.
When the FIRE—BATTERY COMPARTMENT sign came on for the third time, Chang did not hesitate to reset it. A real fire, he knew, would have triggered the extinguishers. In fact, one of his biggest worries was that these might operate unnecessarily.
There were several anomalies on the board now, especially in the battery-charging circuits. As soon as the journey was over and he’d powered down the transporter, Chang was going to climb into the motor room and give everything a good old-fashioned eyeball inspection.
As it happened, his nose alerted him first, when there was barely more than a kilometer to go. Even as he stared incredulously at the thin wisp of smoke oozing out of the control board, the coldly analytical part of his mind was saying, “What a lucky coincidence that it waited until the end of the trip!”
Then he remembered all the energy being produced during the final braking, and had a pretty shrewd guess at the sequence of events. The protective circuits must have failed to operate, and the batteries had been overcharging. One fail-safe after another had let them down. Helped by the ionospheric storm, the sheer perversity of inanimate things struck again.
Chang punched the battery-compartment fire-extinguisher button. At least that worked, because he could hear the muffled roar of the nitrogen blasts on the other side of the bulkhead. Ten seconds later, he triggered the VACUUM DUMP, which would sweep the gas out into space, with, he hoped, most of the heat it had picked up from the fire. That, too, operated correctly. It was the first time that Chang had ever listened with relief to the unmistakable shriek of atmosphere escaping from a space vehicle; he hoped it would also be the last.
He dared not rely on the automatic-braking sequence as the vehicle finally crawled into the terminus. Fortunately, he had been well rehearsed and recognized all the visual signals, so that he was able to stop within a centimeter of the docking adapter. In frantic haste, the air locks were coupled together, and stores and equipment were hurled through the connecting tube.
And so was Professor Sessui, by t
he combined exertions of pilot, assistant engineer, and steward, when he tried to go back for his precious instruments. The air-lock doors were slammed shut just seconds before the engine compartment bulkhead finally gave way.
After that, the refugees could do nothing but wait in the bleak fifteen-meter-square chamber, with considerably fewer amenities than a well-furnished prison cell, and hope that the fire would burn itself out. Perhaps it was as well for the passengers’ peace of mind that only Chang and his engineer appreciated one vital statistic: the fully charged batteries contained the energy of a large chemical bomb, now ticking away on the outside of the Tower.
Ten minutes after their hasty arrival, the bomb went off, causing slight vibrations of the Tower, followed by the sound of ripping and tearing metal. Though the breaking-up noises were not impressive, they chilled the hearts of the listeners. Their only means of transport was being destroyed, leaving them stranded twenty-five thousand kilometers from safety.
There was another, more protracted, explosion—then silence. The refugees guessed that the vehicle had fallen off the face of the Tower. Numbed, they started to survey their resources; and slowly they began to realize that their miraculous escape might have been wholly in vain.
44
A Cave in the Sky
Deep inside the mountain, amid the display and communications equipment of the Earth Operations Center, Morgan and his engineering staff stood around the tenth-scale hologram of the Tower’s lowest section. It was perfect in every detail, even to the four thin ribbons of the guiding tapes extending along each face. They vanished into thin air just above the floor, and it was hard to appreciate that, even on this diminished scale, they should continue downward for another sixty kilometers—completely through the crust of the earth.
“Give us the cutaway,” said Morgan, “and lift the Basement up to eye level.”
The Tower lost its apparent solidity and became a luminous ghost—a long, thin-walled square box, empty except for the superconducting cables of the power supply. The lowest section—“Basement” was indeed a good name for it, even if it was at a hundred times the elevation of this mountain—had been sealed off to form a single square chamber, fifteen meters on a side.
“Access?” queried Morgan.
Two sections of the image started to glow more brightly. Clearly defined on the north and south faces, between the slots of the guidance tracks, were the outer doors of the duplicate air locks—as far apart as possible, according to the usual safety precautions for all space habitats.
“They went in through the south door, of course,” explained the Duty Officer. “We don’t know if it was damaged in the explosion.”
Well, there were three other entrances, thought Morgan, and it was the lower pair that interested him. This had been one of those afterthoughts, incorporated at a late stage in the design. Actually, the whole Basement was an afterthought. At one time it had been considered unnecessary to build a refuge there, in the section of the Tower that would eventually become part of Earth Terminal itself.
“Tilt the underside toward me,” Morgan ordered.
The Tower toppled, in a falling arc of light, and lay floating horizontally in mid-air, with its lower end toward Morgan. Now he could see all the details of the twenty-meter-square floor—or roof, if one looked at it from the point of view of its orbital builders.
Near the north and south edges, leading into the two independent air locks, were the hatches that allowed access from below. The only problem was to reach them—six hundred kilometers up in the sky.
“Life support?”
The air locks faded back into the structure. The visual emphasis moved to a small cabinet at the center of the chamber.
“That’s the problem, Dr. Morgan,” the Duty Officer answered somberly. “There’s only a pressure-maintenance system. No purifiers, and of course no power. Now that they’ve lost the transporter, I don’t see how they can survive the night. The temperature’s already falling—down ten degrees since sunset.”
Morgan felt as if the chill of space had entered his own soul. The euphoria of discovering that the lost transporter’s occupants were still alive faded swiftly away. Even if there was enough oxygen in the Basement to last them for several days, that would be of no importance if they froze before dawn.
“I’d like to speak to Professor Sessui.”
“We can’t tell him directly. The Basement emergency phone goes only to Midway. No problem, though.”
That turned out to be not completely true. When the connection was made, Driver-Pilot Chang came on the line.
“I’m sorry,” he said, “the Professor is busy.”
After a moment’s incredulous silence, Morgan replied, pausing between each word and emphasizing his name: “Tell him that Dr. Vannevar Morgan wants to speak to him.”
“I will, Dr. Morgan—but it won’t make the slightest difference. He’s working on some equipment with his students. It was the only thing they were able to save—a spectroscope of some kind. They’re aiming it through one of the observation windows. . . .”
Morgan controlled himself with difficulty. He was about to retort “Are they crazy?” when Chang anticipated him.
“You don’t know the Prof. I’ve spent the last week with him. He’s—well—I guess you could say single-minded. It took three of us to stop him from going back into the cabin to get some more of his gear. And he’s just told me that if we’re all going to die anyway, he’ll make damn sure that one piece of equipment is working properly.”
Morgan could tell from Chang’s voice that, for all his annoyance, he felt a considerable admiration for his distinguished and difficult passenger. And the Professor did have logic on his side. It made good sense to salvage what he could, out of the years of effort that had gone into this ill-fated expedition.
“Very well,” said Morgan at length, co-operating with the inevitable. “Since I can’t get an appointment, I’d like your summary of the situation. So far, I’ve only had it secondhand.”
It now occurred to him that, in any event, Chang could probably give a much more useful report than the Professor. Though the Driver-Pilot’s insistence on the second half of his title often caused derision among genuine astrogators, he was a highly skilled technician with a good training in mechanical and electrical engineering.
“There’s not much to say. We had such short notice that there was no time to save anything—except that damned spectroscope. Frankly, I never thought we’d make it through the air lock. . . .
“We have the clothes we’re wearing—and that’s about it. One of the students grabbed her travel bag. Guess what—it contained her draft thesis, written on paper, for heaven’s sake. Not even flame-proofed, despite regulations. If we could afford the oxygen, we’d burn it to get some heat. . . .”
Listening to that voice from space, and looking at the transparent—yet apparent solid—hologram of the Tower, Morgan had a most curious illusion. He could imagine that there were tiny, tenth-scale human beings moving around there in the lowest compartment; it was only necessary to reach in his hand to carry them out to safety. . . .
“Next to the cold, the big problem is air. I don’t know how long it will be before CO2 build-up knocks us out. Perhaps someone will work out that as well. Whatever the answer, I’m afraid it will be too optimistic. . . .”
Chang’s voice dropped several decibels and he began to speak in an almost conspiratorial tone, obviously to prevent being overheard.
“The Prof and his students don’t know this, but the south air lock was damaged in the explosion. There’s a leak—a steady hiss around the gaskets. How serious it is, I can’t tell.”
The speaker’s voice rose to normal level again.
“Well, that’s the situation. We’ll be waiting to hear from you. . . .”
And just what the hell can we say, Morgan thought, except “Good-by”?
* * *
Crisis management was a skill Morgan admired, but did n
ot envy. Janos Bartok, the Tower Safety Officer up at Midway, was now in charge of the situation. Those inside the mountain twenty-five thousand kilometers below, and a mere six hundred from the scene of the accident, could only listen to the reports, give helpful advice, and satisfy the curiosity of the news media as best they could.
Needless to say, Maxine Duval had been in touch within minutes of the disaster, and as usual her questions were much to the point.
“Can Midway Station reach them in time?”
Morgan hesitated. The answer to that was undoubtedly “No.” Yet it was unwise, not to say cruel, to abandon hope as early as this. And there had been one stroke of good luck.
“I don’t want to raise false hopes, but we may not need Midway. There’s a crew working much closer, at 10K Station; that’s ten thousand kilometers above them. Their transporter can reach the Basement in twenty hours.”
“Then why isn’t it on the way down?”
“Safety Officer Bartok will be making the decision shortly—but it could be a waste of effort. We think they have air for only half that time. And the temperature problem is even more serious.”
“What do you mean?”
“It’s night up there, and they have no source of heat. Don’t put this out yet, Maxine, but it may be a race between freezing and anoxia.”
There was a pause for several seconds. Then Duval said in an uncharacteristically diffident tone of voice: “Perhaps I’m being stupid, but surely the weather stations, with their big infrared lasers—”
“Thank you, Maxine. I’m the one who’s being stupid. Just a minute while I speak to Midway.”
Bartok was polite enough when Morgan called, but his brisk reply made his opinion of meddling amateurs abundantly clear.