Once they’d all found places to stand, T.R. said, “This here upper part will be filled with hydrogen gas, which is the working fluid that actually pushes the shell up the barrel. The physics of it is beyond me, but they say that the maximum velocity of the projectile can’t be any faster than the speed of sound in the gas that is doing the pushing. The speed of sound in light gases like hydrogen and helium is higher than that in air. Enough to make a difference for our purposes. We looked at helium. The world’s helium supply actually comes from up Amarillo way. It’s safer, but it’s expensive and hard to work with. If you build one of these at the doorstep of Germany, Your Majesty, you’ll want to take a hard look at helium. I can help you get some.”
“Very considerate of you as always, T.R.!”
“Anyways, we settled on hydrogen. Some of it’s gonna leak out and burn, but it’s a desert, so who cares? It’s easy to make more, on-site, from natural gas. So, at the same time the methane-air mix is filling the chamber below, we fill this volume with a certain amount of H2. When the combustion chamber”—he pointed straight down—“goes boom, this piston we’re standing on gets forced upward, compressing the hydrogen. Which only has one way out.” He drew their attention to the top of the cylinder, ten meters above their heads, where it tapered inward like an upside-down funnel to an orifice in the middle about the size of a manhole. If the entire cylinder was a bottle, that was its mouth. “Let’s see where it goes!” he suggested, touching off another round of extension cord wrangling, hatch closing, and ladder climbing that took them up above the top of the massive steel cylinder to Minus One.
If the lower levels had been straight twentieth-century tech with their spark plugs and pistons, Minus One was all modern robotics. Slightly below them was a massive construct that could only be the “mouth” of the “bottle”—the upside-down funnel that accepted and channeled the pulse of hydrogen gas being driven upward by the rising piston. A short distance above that were the bottoms of the six barrels, which were simply cut off at their bases, open to the room. In between those obvious and easy-to-understand elements was an elaborate, massive, rotating contraption that, if Saskia was any judge of these things, had consumed the lion’s share of the engineering resources. She couldn’t really puzzle it out until T.R. issued a command that caused a vertical conveyor system to go into motion. This thing—“Shell hoist” on the cross-sectional diagram—had run parallel to the elevator all the way down from ground level. It served a similar purpose to the lift, but it was smaller and it ran much faster. After it had been whirring along for a minute or so, it slowed.
A giant bullet descended into the room. The bullet was a bit longer than Saskia was tall, and somewhat fatter than a beer keg. It was machined aluminum in some places, carbon fiber in others. It had a Flying S logo and was stenciled “RETURN TO FLYING S RANCH - REWARD” in English and Spanish. It glided down past them on the hoist and was seized by a massive robot arm, which pulled it away, indexed around, and fed it point-first into the base of one of the gun barrels. Another mechanism, pushing up from below, then rammed the shell upward until it had completely disappeared into the barrel. Something went kerchunk. The robot arm retracted, but the shell did not fall out.
“Now, let’s say we want to send it on its way,” T.R. said. He nodded to a technician, who pressed some buttons.
The whole massive robotic platform went into motion, pirouetting around the central axis of the main shaft. Saskia couldn’t help thinking of the big cylinder in a cowboy’s revolver. It had a single large orifice in its top, offset to one side, matching the diameter of the gun barrels. When this was positioned below the breech of the barrel that had just been loaded, the whole thing rose upward in a swift, smooth movement until the connection was made.
“That’s how the hydrogen flows to the barrel,” Bob guessed.
“There’s now a direct unimpeded channel between the two,” T.R. confirmed. “If you were Spiderman you could go back down to Minus Four, into the same port we just used. You could climb up the cylinder wall, through that funnel we looked at, and up a short, oblique, snergly tube to where you could reach up into that barrel and touch the base of that shell we just now loaded.”
“And it’s all hot?” Saskia asked.
T.R. nodded. “Good point, Your Majesty. The shell was pre-heated above, and it’s still hot now—hot enough to keep the sulfur in its molten state. For as long as it sits in that barrel waiting to be fired, it will be kept hot by electrical heaters built into the barrel walls. The space on the other side of this window is quite warm—and it’s about to get warmer.”
“How many of those barrels are loaded?” Bob asked.
“As of now? Six of six. All we gotta do is get out of here and turn on the gas.” He checked his watch. “And then we should be ready for this month’s meeting of the Flying S Ranch Employees’ Model Rocketry Club!”
The elongated bowl, four thousand feet above sea level, in which this complex had been constructed, was referred to by T.R. as Pina2bo (“Pin a two bo”). Anyone familiar with the literature on climate change and geoengineering would get the joke. Pinatubo was the name of a volcano in the Philippines that had exploded in 1991. It had blasted fifteen million tons of sulfur dioxide into the stratosphere. The result had been a couple of years’ beautiful sunsets and reduced global temperatures. The two phenomena were directly related. The sulfur from the volcano had eventually spread out into a veil of tiny droplets of H2SO4. Light from the sun hit those little spheres and bounced. Some of it bounced directly back into space—which accounted for the planet-wide cooling, as energy that never entered the troposphere in the first place couldn’t contribute to the greenhouse effect. Other light caromed off those droplets, billiard-ball style, and came into the troposphere at various oblique angles. Since that was where humans lived, those who lifted their gaze saw that light as a general brightness of the sky. This was hard to notice in the daytime but quite obvious when the sun was near the horizon, the sky was generally dark, and the light was red.
Pinatubo was hardly the first volcano to explode during the time that humans had lived upon the earth. Earlier such events had been followed by cold snaps and awesome sunsets that had entered the historical record in anecdotal form. But Pinatubo was the first, and so far the only really big one, that had happened during the modern era when its results could be scientifically studied.
After a smaller eruption in the 1960s a high-altitude plane had flown through the plume and come back with a residue on its windshield that an Australian scientist had evaluated by licking it. “Painfully acid” was his verdict. He’d experienced exactly the same sensation as Texas oilmen sampling sour crude on their fingers. So there was already evidence, prior to Pinatubo, that volcanoes hurled sulfur compounds into the stratosphere. The 1991 blast found scientists ready to make more sophisticated measurements than windshield licking, and provided the basis for decades of research and modeling of so-called solar geoengineering—the term for any climate mitigation scheme that was based on bouncing part of the sun’s rays back into space.
So Pina2bo was what T.R. called the complex where he planned to do basically the same thing, on a smaller scale. Pina2bo would have to operate full blast for many years to put as much SO2 into the stratosphere as its namesake had done in a few minutes. Since the stuff began to fall out of the atmosphere after a few years, the best that Pina2bo could ever achieve was just a fraction of the real Mount Pinatubo eruption. But enough to begin making a difference. And if the first one worked, more of them could be built.