“The fact was, we didn’t even know whether the world had ended, at that point. Border Town being abandoned wasn’t a good sign, but who knew for sure? We sure as hell didn’t. And seeing the desert empty didn’t tell us much, either. It would be empty, under almost any circumstance. I stepped through the opening up there and the first thing I did was stare at the sky for over a minute, hoping to see a jet contrail. Imagine if I had.”
The notion struck Travis hard, and he wondered why he hadn’t considered it until now: what if the future on the other side of the iris hadn’t been a ruined one? What if Paige and the others had encountered a thriving world instead, decades and decades ahead of the present day? What would they have learned from a world like that? What would they have gained?
He saw in Paige’s eyes a ghost of the optimism she must’ve felt, standing there under the desert sky Tuesday morning.
Then it faded.
“We started running the obvious tests after that,” she said. “First an easy one: we switched on a handheld GPS unit, on the other side, and tried to pick up satellites with it. And we found some. But the position readings were a mess. The satellites were up there, but they weren’t where they were supposed to be. One of the four of us, Pilar Guitierrez, spent about twenty years with NASA’s Jet Propulsion Lab. She knew everything about orbital dynamics, drift and decay rates, that kind of thing. Orbits are a lot more fragile than most people think. Satellites get tugged around by all kinds of things. The moon’s gravity. The sun’s gravity. The tilt of the Earth plays hell with their inclinations. All that stuff has to be dealt with, all the time, by a process called station-keeping. Satellites are equipped with small rockets for corrective burns, to nudge them back onto course once in a while, and the commands for those burns come from human operators on the ground. But given what we were seeing on the handheld unit, the GPS satellites hadn’t heard from anyone on the ground in a long, long time.”
She exhaled slowly. “So that was that. We tried other things. We took radio equipment through. We listened to every frequency range with the most sensitive gear we had. Certain bandwidths, those that are popular with ham radio operators, we could’ve picked up from halfway around the world—if there were anyone out there transmitting on them. We didn’t hear anything.”
She finished off the Pepsi and set it aside.
“The only other thing we could do from a remote location like that was try to get through to a communication satellite. Our hope was that we might find one with some retrievable data on board. Something we could make sense of. Anything. But signals from those satellites are a lot harder to receive than GPS. You can’t pick them up with a handheld unit bouncing around in your pocket. You need a dish, and you need to know exactly where to point it. Engineers handle that problem by putting comm satellites in geostationary orbit, right above the equator and matched to the spin of the Earth. That way the satellite is always in the same place, relative to the ground. But that wasn’t going to help us: if those orbits had decayed much at all, the satellites would be lower, and orbiting faster. They wouldn’t be stationary anymore. So when it came to aiming the dish, we’d be shooting in the dark at moving targets.”
Her eyebrows went up in a shrug. “We had to try, though. So we did. We picked a spot above the equator, well below geostationary altitude, and we transmitted a maintenance ping every thirty seconds. A universal signal most satellites would respond to, if they heard it. We did that for hours and hours, all through the afternoon and into the evening, but there was no reply. We kept it going anyway. There was reason to believe it could take a while. In the meantime we tested other things. We figured out the use of the delayed shutoff button. We also figured out what the sequence of tones had been all about, the first time we’d switched on one of the cylinders.”
Paige looked past Travis to the backpack lying in the empty chair next to him. She stared at the shape of the cylinder inside.
“It was locking out changes,” she said.
Travis glanced at Bethany, then looked at Paige again. “Locking out changes?”
Paige nodded. “It’s hard to explain. Hard to understand in the first place. In my case, I just saw it in action. While Pilar was working with the satellite gear, I had an idea I wanted to try. I took the second cylinder, and in the present time I drove one of the electric Jeeps to a little sandstone boulder about half a mile north of Border Town.”
Travis recalled the rock she was talking about, though he’d only seen it a few times. It was about the size of a compact car, and it was the only thing larger than a scrub plant within miles of the elevator housing on the surface.