On Day 306, after Arklets 2 and 3 had been assembled and checked out, the first Bolo Coupling Operation was initiated. It happened several kilometers away from Izzy. It was done quietly and secretly, in case it failed, but lots of video was taken, in case it succeeded. The operation had many possible failure modes, which was engineering-speak meaning that it could go wrong in so many different ways that trying to think them all through was impossible. So each of the two arklets needed to have a qualified pilot: someone who understood orbital mechanics and spaceship propulsion well enough to bring an errant craft back in hand by manual control. Few such people had ever existed, and only four of them were aboard Izzy. Right now, down on the ground, thousands of young people selected in the Casting of Lots were learning how to do it by piloting virtual arklets in video game simulations, but none of those people was ready, or in orbit, yet. So Ivy ended up at the controls of Arklet 2, with Dinah as passenger and general assistant. Piloting Arklet 3 was a recent arrival, Markus Leuker, a Swiss air force pilot turned astronaut and a veteran of two previous missions to the ISS. His background piloting high-performance fighter jets through Alpine valleys seemed like a reasonable qualification for this job. His assistant was Wang Fuhua, one of the first Chinese taikonauts to have reached Izzy during the Pioneer days of a few months back.
After a good night’s sleep and a light breakfast, the four participants met in the Banana to go over the details one last time with engineers on the ground, then ascended a spoke into the weightless environment of H1 and glided up the Stack—the central axis of the space station—snaking through work bays and temporary supply dumps until they reached a docking node that, after a few twists and turns, led them into a hamster tube. One after the other they slithered down it. Dinah, in number three position behind Markus, found it difficult to keep up with him; the soles of his feet kept getting farther and farther away. “Just like scaling the Daubenhorn,” he said at one point, “except without the annoyance of gravity!”
“Is that a mountain?” Dinah asked, since the hamster tube was long, and she felt that a bit of light conversation would help ease the lump in her stomach.
“Yes, a famous Klettersteig where I grew up—you must come and give it a try one of these days,” Markus called back.
A common error in etiquette, among people who had only recently arrived at Izzy, was to talk about Earth as a place that it was possible to go back to. As if this were a temporary mission like all of the previous ones. Dinah said nothing. Markus would realize his mistake, if he hadn’t already.
“Oh, well,” he added. Yes, he had realized it.
“What’s a Klettersteig?” Dinah asked, trying to move on.
“It is a mountain climb that is preengineered with cables, ladders, and so on.”
“To make it easier,” Dinah guessed.
“Oh, no. It is not easy. It is a way to take a climb that would be impossible, and make it merely extremely difficult.”
“Okay,” Dinah said. “A good metaphor for what we are trying to do up here, then.”
“Yes, I suppose so!” Markus said, cheerfully enough.
They came to a junction of hamster tubes, and after scrutinizing the felt-tipped annotations on the walls left by past travelers, they went their separate ways, Dinah leading Ivy to the right while Fuhua and Markus headed straight on. After passing three occupied docking ports, and exchanging perfunctory greetings with the people living in the capsules on the other sides, they came to the end of the hamster tube and passed through a docking port.
They floated into a tubular space four meters in diameter and twelve meters long, illuminated by icy bluish-white LEDs. Its wall was a smooth cylinder of aluminum, striped with bar codes and stippled with batch numbers from the mill that had produced it. A long, straight weld ran up its length. At the far end, the curve of its “boiler room” dome, penetrated by many plumbing and electrical connections, was visible through a flat fiberglass grate—a disk of industrial catwalk material in a bilious shade of green. A ladder, made of the same material, extended “up” from there to the “front door,” through which Dinah, and now Ivy, entered. It put Dinah immediately in mind of Markus with his talk of Klettersteigs. You didn’t need to have a ladder unless you were expecting gravity, or a reasonable facsimile of it. The grate at the far end of the arklet was going to end up serving as the floor.
Or as a floor—the lowermost story. The arklet was long enough to divide vertically into as many as five stories by inserting more of those grated disks. Cleats for that purpose were attached to the walls at regular intervals, but the grates hadn’t been installed yet.