Hieroglyph (9 page)

Which was how Roger, Frog, and I ended up abseiling three kilometers straight down the tower's central shaft on a rescue mission.

Why us three? Well, Frog was the veteran BASE jumper, a little past his prime and above his station, but—bottom line—the only way to prevent him from coming would have been to hit him on the head with a wrench and ziptie him to a girder. Roger, true to his pedigree, had mountaineering experience.

And I knew as much about the tower's weird little ins and outs as anyone.

The central shaft, which would one day be filled with some as-yet-unbuilt space launch tech, was empty. Ever-pragmatic construction workers had strung long cables down it, like mountaineers' ropes. They used mechanical descenders to glide down when they wanted to get lower but didn't have time to mess about with helirails. There were also elevators, but these had all shut themselves off when the superbolt had fritzed their electronics, and there seemed no way to reboot them without getting through to a customer service rep in Pakistan. Roger, the biggest member of our group, slung an extra space suit on his back (these folded up, sort of, into backpackable units, bulky but manageable). This was just in case Joe was in need of one. Hiram showed us how to harness the descenders to the outside of our suits. Each of us connected to a different cable—there were plenty of them—and then we backed off the rim of the shaft and let ourselves drop.

So this was a tubular vacancy, ten meters across and (currently) seventeen thousand meters long. Walking to the edge of it and looking straight down had become a popular tourist activity on the Top Click. To put this in perspective, it had the same relative dimensions as a forty-foot-long soda straw. As a rule, it was perfectly straight, as if it had been laser-drilled through a cube of granite. Quite a trick given that it was held in place by a wind-buffeted gas of metal.

Tonight, though, it was sashaying. You couldn't see the bottom from the top. It was like staring down the gullet of an undulating snake. Because, in Hiram's phrasing, the tower wasn't flying right. Its accustomed straightness was a process, not a state; it was made straight from one moment to the next by a feedback loop that had been severed.

As alarming as it looked, the undulation wasn't as huge as it appeared from above, and once we had adjusted the tension in our descenders, we were able to plunge more or less straight down. In a forty-foot soda straw, even a little bend looks enormous.

The self-weight of the cables became a problem after a while and so they terminated every hundred meters, forcing us to stop and transfer to new ones. It took us thirty transfers, and as many minutes, to get down to the altitude where Joe had detrained some hours ago.

This brought us into the Neck, the skinniest part of the tower, but in some ways the most complicated. The Top Click was destined to be the domain of gamblers and scientists. The bottom kilometers would be a city with an airport on its roof. The central core, a somewhat mysterious ballistics project. But the Neck was the domain of engineers: mechanical, control-system, and aeronautical. That's because it was here that the wind stress was at its peak, and here that it had to be addressed with what were called “active measures.” The most conspicuous of these were the airfoils, large enough for people to walk around inside of them. At one level there was also an array of turbofan engines, the same as you see on airliners, which had been put there as a last-ditch measure in the event of a full-on jet stream hit. If that ever happened we would just fuel them up, turn them on, and run them full blast, thrusting back against the force of the wind, until the jet stream wandered away, a few hours or days later.

All of this gear for playing games with enormous forces had made the Neck beefier by far than the rest of the tower, and so as we descended silently into it, our view of the stars and of the curving horizon was interrupted, then cluttered, and finally all but blotted out by a mare's nest of engineering works, most of it wrapped in streamlined airfoils to make it less draggy.

At our target altitude, six horizontal braces radiated from the core to the six primary legs of the tower. These were trusses, webs of smaller members triangulated into rigid systems, looking a bit like radio towers laid on their sides. Plastic tubes had been built around them, forming airtight corridors. Those in turn had been encased in aerodynamic sheaths. Six of those converged like spokes on the place where we stopped our descent and unhooked ourselves from the descenders. Moving deliberately, clipped to safety rails, leapfrogging from one handhold to the next—for the wind was fearsome—we made our way to the airlock that afforded entry to the southeastern strut/truss/tube/airfoil. Based on information from Joe's boss, I believed we would find him at the end of it. So I was dismayed when the airlock's control panel gave us the news that the tube was depressurized. This thing was supposed to be full of a proper atmosphere so that engineers could move along it without having to leave that all-important shirtsleeves environment. But apparently the superbolt had caused it to spring a leak. This was okay for me, Roger, and Frog, but I didn't know what it might portend for Joe.

In any case, opening the door was easy since we didn't have to cycle the airlock. We were confronted by a view down a straight tube a thousand meters long, illuminated dimly by blue LEDs. The steel truss had been equipped with plastic catwalk grating. We started walking. This would have been a lot easier in an atmosphere. As it was, I wished we'd had some of those electric scooters, like on the Top Click. The designers of those suits had made the best of a tough design challenge, but at the end of the day they were made for passive survivors awaiting rescue by people in
real
space suits. Hiking down a catwalk wasn't in the design spec. It was like wading through wet cement and feeling it start to harden whenever you planted a foot. I wanted to break the mood with a joke about what great cardio this was, but I was too out of breath, and judging from the sound effects in my headphones, Roger and Frog weren't doing much better.

I was about ready to start whining about how hard it all was when we got to the end of the tube—meaning we had reached the southeastern Primary—and walked through another dead airlock into the pod where Joe had been working.

© 2013, Haylee Bolinger / ASU

The pod was spherical. A floor and a ceiling had been stretched across it to turn it into a round room about the size of a two-car garage. The dome-shaped spaces above and below were packed respectively with electronics and with survival gear. The first thing I noticed when I walked in was an open floor hatch, which gave me hope that Joe had had time to yank it open and grab a suit.

But Joe wasn't in here.

My eye was drawn to a scarlet flash on the other side of the darkened room. I realized I was looking straight out through a hole that had been blasted in the spherical shell. The red flash had been one of those sprites, off in the distance, high above the top of the thunderstorm as it migrated eastward.

Frog bent down and picked up an overturned swivel chair. Its plastic upholstery was patchy where it had melted and congealed.

On the workspace where Joe had been seated, and on the jagged twists of metal around the rupture, was a mess that I couldn't identify at first—because I didn't want to. And when I did, I almost threw up in my suit. Joe hadn't opened the floor hatch, I realized. It had been blown open when this whole pod had explosively decompressed. The atmosphere had blasted out the hole, taking Joe with it. Later forensic analysis suggested he'd been killed instantly by the superbolt, so at least he'd been spared the experience of being spat out, fully conscious, into free fall. But none of that changed the fact that, through no fault of his own, he'd been sitting in the wrong place at the wrong time. He had become the third accidental fatality on the tower construction project. Number one had been early—a forklift mishap, moving some steel around. Number two had been only a couple of months ago: a taut cable had been snapped by a wayward crane; the broken end recoiled under tension and struck a worker hard enough to break his neck. Joe was number three, killed instantly by an upward superbolt: a species of upper-atmosphere monster of which we had known only traces and rumors when the tower had been designed.

What we did next got described all wrong in the news reports. Oh, they weren't factually incorrect, but they got the emotional tenor wrong. Yes, seeing that the southeastern control node had been blitzed off the network, we concluded that its responsibilities would have to be shunted to other nodes on the same level that still had luxuries such as power and atmosphere. Lacking communication with the ground, we had to make do with a few erratic cell-phone conversations. Roger, Frog, and I spread out to the south, northeast, and north control nodes on the same level—lots more cardio—and finally took those cursed suits off and, following instructions from the ground, repatched cables and typed in arcane computer commands until control had been transferred. The tower stopped swaying and, as the control loops recalibrated to its new aerodynamics, stopped vibrating as well. All of that was true. But the news feeds described it as an Apollo 13 type of crisis, which it never was. They made it sound like we were doing really cool, difficult work under pressure, when in reality most of it was sitting in shirtsleeves (sorry, Carl!) and typing. And they totally failed to understand the context and the tone that had been set by the death of Joe.

The one thing they got right was what happened in the wee hours that followed: Hiram and Frog going out on the damaged airfoil to corral loose pieces of metal that were banging around in the wind and that could have inflicted catastrophic damage had they come loose. That was really dangerous work, performed at great personal risk without proper safety lines and, because it took longer than expected, with dwindling air supplies and cold-numbed digits. Frog, true to BASE-jumper tradition, went out the farthest, and took the biggest risks—maybe because he had a parasail strapped to his back. And, though he later denied it, I think he had a plan. Only after all of the loose debris had been securely lashed and tack-welded down did he “fall off” in an “unexpected wind gust” and free-dive for a few thousand meters before deploying his parasail and enjoying a long ride down to terra firma. You've seen the YouTube of him touching down in the desert at dawn, popping off his helmet, gathering up his chute, and striding toward the camera to make the grim announcement that a man had died up on the tower last night. Standing there in his space suit, unshaven, exhilarated by his “fall” but sobered by the grisly scene he'd witnessed in the pod, he looked like nothing other than an astronaut.

And an astronaut he was, on that morning. One without a rocket. Exploring, and embracing the dangers, not of outer space but of the atmosphæra incognita that, hidden from earthlings' view by thunderheads, stretches like an electrified shoal between us and the deep ocean of the cosmos.

Demeshko Alexandr/Shutterstock, Inc.

STORY NOTES
—Neal Stephenson

The Tall Tower idea is based on papers written by Geoffrey A. Landis (“Compression Structures for Earth Launch,” 1998) and Landis and Vincent Denis (“High Altitude Launch for a Practical SSTO,” 2003). In addition, the author is grateful to Keith D. Hjelmstad of Arizona State University for many illuminating discussions of the structural ramifications; Ed Finn and Michael Crow, also of ASU, for fostering Project Hieroglyph and the Center for Science and the Imagination; and Daniel MacDonald, Jenny Hu, and Kevin Finke for their participation in further analysis of the tower idea. The idea of using engines to push back against jet stream events should be credited to Jeff Bezos. Finally, Gregory Benford's enthusiasm for the idea and the story are noted with warm appreciation.

STRUCTURAL DESIGN OF THE TALL TOWER
—
Keith D. Hjelmstad

Read a technical paper about the structural design of the Tall Tower by Keith D. Hjelmstad of Arizona State University at hieroglyph.asu.edu/tall-tower.