Arthur Clarke - Firstborn

The ground fell away, the historic clutter of Canaveral already diminishing to a map.

A minute into the journey, four kilometers high, and the world was starting to curve, the eastern ocean horizon an immense arc. And with a snap the big solar-cell wings folded down flat.

“I don’t get it,” Bisesa said. “This is for power? The solar cells seem to be on the underside.”

“That’s the idea,” Alexei said. “The spider’s power comes from ground-based lasers.”

“You saw them, Mum,” Myra said.

“You leave your power supply on the ground. Okay. So how long is the ride?”

“To beyond geosynch? All the way out to our drop-off point?

Around twelve days,” Alexei said.

“Twelve days in this box?” And Bisesa didn’t like the sound of that phrase, drop-off.

“This is a big structure, Mum,” Myra said, but she was evidently a novice herself and didn’t sound convinced.

A few more minutes and they were eight kilometers high, already higher than most aircraft would fly, and there was a clunk, the mildest of shudders. Over their heads the pulley mechanism alarmingly reconfigured itself, bringing a different set of wheels and tracks into play.

And then, suddenly, the ribbon itself changed, from a narrow strip the width of Bisesa’s hand to a sheet as wide as an opened-out newspaper. It was sharply curved, she saw. Their spider now clung to one outer edge of the ribbon.

Alexei said, “This is the standard width of the ribbon, most of the way to orbit. It’s kept narrower in the lower atmosphere because of the threat regime down there. Of course most of the bad weather is kept away nowadays. The ribbon’s worst problems actually come when they launch one of those Saturn s; the whole damn earth shakes, and I can tell you there’s a lot of grumbling about that.”

Ten kilometers, twelve, fifteen; the distance simply peeled away. Earth’s curve became more pronounced, and the sky above Bisesa’s head started to fade down to a deeper blue. She was above the bulk of the atmosphere already, she realized.

Another abrupt transition came when the ribbon turned gold: a plating to protect it from the corrosive effects of high-altitude atomic oxygen, Alexei said, ionized gas in Earth’s wispy upper air.

And still they rose and rose.

“So let’s get comfortable.” Alexei ordered his suitcase to open.

“The pressure will drop to its spaceside mix — low pressure, a third atmospheric, but high on oxygen. In the meantime I brought oxygen masks.” He showed them, and a rack of bottles. “And it’s going to get cold. Your jumpsuits ought to keep you warm. I have heated blankets too.” He rummaged about in his suitcase. “We’re going to be in here a while. I have fold-out camp beds and chairs. A bubble tent in case you don’t want to sleep under the stars, so to speak. I have heaters for food and drink. We’re going to have to recycle our water, I’m afraid, but I have a good treatment system.”

“No spacesuits,” Bisesa said.

“Shouldn’t need them, unless anything goes wrong.”

“And if it does?”

He looked at her, as if assessing her nerve. “Second worst case is, we get stuck on the cable. There are a whole slew of fail-safe mechanisms to save us until rescue comes, via another spider. Even if we were to lose pressure, we have survival bubbles. Hamster balls. Not comfortable, but practical.”

Hamster balls? Bisesa hoped fervently that it wouldn’t come to that. “And the worst case?”

“We become detached from the ribbon altogether. You understand that a certain point on the elevator is in geosynch—

geosynchronous orbit, turning around the Earth in exactly twenty-four hours. That’s the only altitude that is actually in orbit, strictly speaking. Below that point we are moving too slowly for orbit, and above too fast.”

“So if the spider were to lose its grip—”

“Below geosynch, we fall back to Earth.” He rapped the transparent hull. “Might not look like it, but it is designed to survive a low-speed reentry.”

“And after geosynch? We’d fall away from Earth, right?”

He winked. “Actually that’s the idea. Don’t worry about it.” He held up a flask. “Coffee, anybody?”

Myra grunted. “Maybe we ought to get your fancy toilet set up first.”

“Good thinking.”

While they fiddled with the toilet, Bisesa gazed out of the window.

Riding silently into the sky, soon she was a hundred kilometers high, higher even than the old pioneering rocket planes, the X-15 s, used to reach. The sky was already all but black above her, with a twinkling of stars right at the zenith, a point to which the ribbon, gold-bright in the sunlight, pointed like an arrow. Looking up that way she could see no sign of structures further up the ribbon, no sign of the counterweight mass that she knew had to be at the ribbon’s end, nothing but the shining beads of more spiders clambering up this thread to the sky. She suspected she still had not grasped the scale of the elevator, not remotely.

By an hour and a half in, the fast pace of the events of the early moments of the climb was over. Somewhere above three hundred kilometers high, she could already see the horizon all the way around the face of the Earth, with the ribbon arrowing straight down to the familiar shapes of the American continents far beneath her. Though the stars would wheel around her during this extraordinary ascent, she realized, the Earth would stay locked in place below. It was as if she had been transported to a medieval universe, the cosmos of Dante, with a fixed Earth surrounded by spinning stars.

When she stood she felt oddly light on her feet. One of Alexei’s softscreen displays mapped the weakening of gravity as they clambered away from Earth’s huge mass. It was already down several percent on its sea-level value.

The silent, straight-line ascent, the receding Earth, the shaft of ribbon-light that guided her, the subtle reduction of weight: it was a magical experience, utterly disconcerting, like an ascent into heaven.

Two hours after “launch” the ribbon changed again, spreading out to a curved sheet twice the width of its standard size — still only about two meters across, and gently curved.

Bisesa asked, “Why the extra thickness?”

“Space debris,” Alexei said. “I mean, bits of old spacecraft.

Lumps of frozen astronaut urine. That sort of stuff. Between five and seventeen hundred kilometers, we’re at the critical risk altitude for that. So we have a bit of extra width to cope with any impact.”

“And if we are hit by something—”

“Anything so big it would slice the ribbon right through is tracked, and we just move the whole shebang out of the way using the crawler on the ground. Anything smaller will puncture the ribbon, but it’s smart enough to mend itself. The only problem is if we’re unlucky enough to be hit by something small coming sideways in, across the face of the ribbon.”

“Which is why the ribbon is curved,” Bisesa guessed.

“Yes. So it can’t be cut through. Don’t worry about it.”

Myra, peering up, said, “I think I see another spider. On the other side of the ribbon from us. I think — oh, wow.”

The second spider came screaming down out of the sky, passing just half a meter away. They all flinched. Bisesa had a brief reminder of their huge speed.

“A builder,” Alexei said, a bit too quickly for his studied calm to be convincing. “Traveling down the ribbon, weaving an extra couple of centimeters onto the edge.”

Bisesa asked, “What’s the substance of the ribbon?”

“Fullerenes. Carbon nanotubes. Little cylinders of carbon atoms, spun into a thread. Immensely strong. The whole ribbon is under tension; the Earth’s spin is trying to fling the counterweight away, like a kid swinging a rock on a rope. No conventional substance would be strong enough. So the spiders go up and down, weaving on extra strips, and binding it all with adhesive tape.”