Cities in Flight

CHAPTER TWO: Jupiter V

… it is the plunge through the forbidden zones that catches the heart with its sheer audacity. In the history of life there have been few such episodes. It is that which makes us lonely. We have entered a new corridor, the cultural corridor. There has been nothing here before us. In it we are utterly alone. In it we are appallingly unique. We look at each other and say, “It can never be done again.”

—LOOREN C. ELSELEY

ASCREECHING tornado was rocking the Bridge when the alarm sounded; the whole structure shuddered and swayed. This was normal, and Robert Helmuth on Jupiter V barely noticed it. There was always a tornado shaking the Bridge. The whole planet was enswathed in tornadoes and worse.

The scanner on the foreman’s board was given 114 as the sector where the trouble was. That was at the northwestern end of the Bridge, where it broke off, leaving nothing but the raging clouds of ammonia crystals and methane, and a sheer drop thirty miles down to the invisible surface. There were no ultra-phone “eyes” at that end to show a general view of the area—in so far as any general view was possible—because both ends of the Bridge were incomplete.

With a sigh, Helmuth put the beetle into motion. The little car, as flat-bottomed and thin through as a bedbug, got slowly under way on its ball-bearing races, guided and held firmly to the surface of the Bridge by ten close-set flanged rails. Even so, the hydrogen gales made a terrific siren-like shrieking between the edge of the vehicle and the deck, and the impact of the falling drops of ammonia upon the curved roof was as heavy and deafening as a rain of cannon balls. In fact, the drops weighed almost as much as cannon balls there under Jupiter’s two-and-a-half-fold gravity, although they were not much bigger than ordinary raindrops. Every so often, too, there was a blast, accompanied by a dull orange glare, which made the car, the deck, and the Bridge itself buck savagely; even a small shock wave traveled through the incredibly dense atmosphere of the planet like the armor-plate of a bursting battleship.

These blasts were below, however, on the surface. While they shook the structure of the Bridge heavily, they almost never interfered with its functioning. And they could not, in the very nature of things, do Helmuth any harm.

Helmuth, after all, was not on Jupiter—though that was becoming harder and harder for him to bear in mind. Nobody was on Jupiter; had any real damage ever been done to the Bridge, it probably would never have been repaired. There was nobody on Jupiter to repair it; only the machines which were themselves part of the Bridge.

The Bridge was building itself. Massive, alone, and lifeless, it grew in the black deeps of Jupiter.

It had been well planned. From Helmuth’s point of view—that of the scanners on the beetle—almost nothing could be seen of it, for the beetle tracks ran down the center of the deck, and in the darkness and perpetual storm even ultrawave-assisted vision could not penetrate more than a few hundred yards at the most. The width of the Bridge, which no one would ever see, was eleven miles; its height, as incomprehensible to the Bridge gang as a skyscraper to an ant, thirty miles; its length, deliberately unspecified in the plans, fifty-four miles at the moment and still increasing—a squat, colossal structure, built with engineering principles, methods, materials and tools never touched before now ….

For the very good reason that they would have been impossible anywhere else. Most of the Bridge, for instance, was made of ice: a marvelous structural material under a pressure of a million atmospheres, at a temperature of 94° below zero Fahrenheit. Under such conditions, the best structural steel is a friable, talc-like powder, and aluminum becomes a peculiar transparent substance that splits at a tap; water, on the other hand, becomes Ice IV, a dense, opaque white medium which will deform to a heavy stress, but will break only under impacts huge enough to lay whole Earthly cities waste. Never mind that it took millions of megawatts of power to keep the Bridge up and growing every hour of the day; the winds on Jupiter blow at velocities up to twenty-five thousand miles per hour, and will never stop blowing, as they may have been blowing for more than four billion years; there is power enough.

Back home, Helmuth remembered, there had been talk of starting another Bridge on Saturn, and perhaps later still on Uranus too. But that had been politicians’ talk. The Bridge was almost five thousand miles below the visible surface of Jupiter’s atmosphere—luckily in a way, for at the top of that atmosphere the temperature was 76? Fahrenheit colder than it was down by the Bridge, but even with that differential the Bridge’s mechanisms were just barely manageable. The bottom of Saturn’s atmosphere, if the radiosonde readings could be trusted, was just 16,878 miles below the top of the Saturnian clouds one could see through the telescope, and the temperature down there was below —238° F. Under those conditions, even pressure-ice would be immovable, and could not be worked with anything softer than itself.

And as for a Bridge on Uranus ….

As far as Helmuth was concerned, Jupiter was quite bad enough.

The beetle crept within sight of the end of the Bridge and stopped automatically. Helmuth set the vehicle’s “eyes” for highest penetration, and examined the nearby I-beams.

The great bars were as close-set as screening. They had to be, in order to support even their own weight, let alone the weight of the components of the Bridge. The gravity down here was two and a half times as great as Earth’s.

Even under that load, the whole webwork of girders was flexing and fluctuating to the harpist-fingered gale. It had been designed to do that, but Helmuth could never help being alarmed by the movement. Habit alone assured him that he had nothing to fear from it.

He took the automatic cut-out of the circuit and inched the beetle forward on manual control. This was only Sector 113, and the Bridge’s own Wheatstone scanning system—there was no electronic device anywhere on the Bridge, since it was impossible to maintain a vacuum on Jupiter—said that the trouble was in Sector 114. The boundary of that sector was still fully fifty feet away.

It was a bad sign. Helmuth scratched nervously in his red beard. Evidently there was cause for alarm—real alarm, not just the deep grinding depression which he always felt while working on the Bridge. Any damage serious enough to halt the beetle a full sector short of the trouble area was bound to be major.

It might even turn out to be the disaster which he had felt lurking ahead of him ever since he had been made foreman of the Bridge —that disaster which the Bridge itself could not repair, sending a man reeling home from Jupiter in defeat.

The secondaries cut in, and the beetle hunkered down once more against the deck, the ball-bearings on which it rode frozen magnetically to the rails. Grimly, Helmuth cut the power to the magnet windings and urged the flat craft inch by inch across the danger line.

Almost at once, the car tilted just perceptibly to the left, and the screaming of the winds between its edges and the deck shot up the scale, sirening in and out of the soundless-dogwhistle range with an eeriness which set Helmuth’s teeth on edge. The beetle itself fluttered and chattered like an alarm-clock hammer between the surface of the deck and the flanges of the tracks.

Ahead there was still nothing to be seen but the horizontal driving of the clouds and the hail, roaring along the length of the Bridge, out of the blackness into the beetle’s fanlights, and onward into darkness again toward the horizon which, like the Bridge itself, no eye would ever see.

Thirty miles below, the fusillade of hydrogen explosions continued. Evidently something really wild was going on down on the surface. Helmuth could not remember having heard so much vulcanism in years.

There was a flat, especially heavy crash, and a long line of fuming orange fire came pouring down the seething air into the depths, feathering horizontally like the mane of a Lipizzan stallion, directly in front of Helmuth. Instinctively, he winced and drew back from the board, although that stream of flame actually was only a little less cold than the rest of the storming, streaming gases, and far too cold to injure the Bridge.

In the momentary glare, however, he saw something: an upward twisting of shadows, patterned but obviously unfinished, fluttering in silhouette against the lurid light of the hydrogen cataract.

The end of the Bridge.

Wrecked.