Project Hail Mary

Chapter 13

“Mr. Easton, I don’t think we need to be searched,” said Stratt.

“I think you do,” said the head prison guard. His thick New Zealand accent sounded friendly, but there was an edge to it. This man had made a whole career out of not putting up with people’s crap.

“We’re exempt from all—”

“Stop,” Easton said. “No one gets in or out of Pare without a full search.”

Auckland Prison, which the locals called “Pare” for some reason, was New Zealand’s only maximum-security prison unit. The sole point of entry was awash with security cameras and a micro-scanner for all guests. Even the guards passed through the detector on their way in.

Easton’s assistant and I stood off to the side while our bosses had their dispute. He and I looked at each other and mutually shrugged. A small fraternity of underlings with stubborn bosses.

“I’m not turning over my Taser. I can call your prime minister if you like,” Stratt said.

“Sure,” said Easton. “She’ll tell you the same thing I’m about to tell you now: We don’t let weapons anywhere near those animals in there. Even my own guards only have batons. There are some rules we don’t change. I’m fully aware of your authority, but it has limits. You’re not magical.”

“Mr. E—”

“Torch!” Easton said, holding out his hand.

His assistant handed over a small flashlight. He clicked it on. “Please open your mouth wide, Ms. Stratt. I need to check for contraband.”

Whoa boy. I stepped forward before this got any worse. “I’ll go first!” I opened my mouth wide.

Easton shined the light into my mouth and looked this way and that. “You’re clear.”

Stratt just glared at him.

He held the flashlight at the ready. “I can get a female guard in here and order a much more thorough search if you like.”

For a few seconds, she did nothing. Then she pulled her Taser from its holster and handed it over.

She must have been tired. I’d never seen her give up on a power trip before. Though, I also hadn’t seen her get into a useless peeing contest before either. She had a lot of authority and wasn’t afraid to flex when needed, but she usually wasn’t one to argue when a simple solution was present.

Soon, guards escorted Stratt and me through the cold, gray walls of the prison.

“What the heck is wrong with you?” I said.

“I don’t like little dictators in their little kingdoms,” she said. “Drives me crazy.”

“You can bend a little once in a while.”

“I’m out of patience and the world is out of time.”

I held up a finger. “No, no, no! You can’t just use ‘I’m saving the world’ as an excuse every time you’re a jerk.”

She thought it over. “Yeah, okay. You may have a point.”

We followed the guards down a long corridor to the Maximum Security Unit.

“Maximum security seems like overkill,” she said.

“Seven people died,” I reminded her. “Because of him.”

“It was accidental.”

“It was criminal negligence. He deserves what he got.”

The guards led us around a corner. We followed along. The whole place was a maze.

“Why bring me here at all?”

“Science.”

“As always.” I sighed. “Can’t say I like this.”

“Noted.”

We entered a stark room containing a single metal table. On one side sat a prisoner in a bright-orange jumpsuit. A balding man in his late forties, maybe early fifties. He was handcuffed to the table. He didn’t look anything like a threat.

Stratt and I sat down opposite him. The guards closed the door behind us.

The man looked at us. He tilted his head slightly, waiting for someone to speak.

“Dr. Robert Redell,” Stratt said.

“Call me Bob,” he said.

“I’ll call you Dr. Redell.” She pulled a file out of her briefcase and looked it over. “You’re currently serving a life sentence for seven counts of culpable homicide.”

“That’s their excuse for me being here, yes,” he said.

I piped up. “Seven people died on your rig. Because of your negligence. Seems like a pretty good ‘excuse’ for you to be here.”

He shook his head. “Seven people died because the control room didn’t follow procedure and activated a primary pumping station while workers were still in the reflector tower. It was a horrible accident, but it was an accident.”

“Enlighten us, then,” I said. “If the deaths at your solar farm weren’t your fault, why are you here?”

“Because the government thinks I embezzled millions of dollars.”

“And why do they think that?” I asked.

“Because I embezzled millions of dollars.” He adjusted his shackled wrists into a more comfortable position. “But that had nothing to do with the deaths. Nothing!”

“Tell me about your blackpanel power idea,” Stratt said.

“Blackpanel?” He drew back. “It was just an idea. I emailed that anonymously.”

Stratt rolled her eyes. “Do you really think email sent from a prison computer lab is anonymous?”

He looked away. “I’m not a computer guy. I’m an engineer.”

“I want to hear more about blackpanel,” she said. “And if I like what I hear, it could reduce your jail time. So start talking.”

He perked up. “Well…I mean…okay. What do you know about solar thermal power?”

Stratt looked at me.

“Uh,” I said. “It’s when you have a whole bunch of mirrors set up to reflect sunlight to the top of a tower. If you get a few hundred square meters of mirror focusing all that sunlight onto a single point, you can heat up water, make it boil, and run a turbine.”

I turned to Stratt. “But that’s not new. Heck, there’s a fully functional solar thermal power plant in Spain right now. If you want to know about it, talk to them.”

She silenced me with a hand motion. “And that’s what you were making for New Zealand?”

“Well,” he said. “It was funded by New Zealand. But the idea was to provide power for Africa.”

“Why would New Zealand pay a bunch of money to help Africa?” I asked.

“Because we’re nice,” Redell said.

“Wow,” I said. “I know New Zealand is pretty cool but—”

“And it was going to be a New Zealand–owned company that charged for the power,” Redell said.

“There it is.”

He leaned forward. “Africa needs infrastructure. To do that, they need power. And they have nine million square kilometers of useless land that gets some of the most intense continuous sunlight on Earth. The Sahara Desert is just sitting there, waiting to give them everything they need. All we needed to do was build the damn power plants!”

He flopped back in his chair. “But every local government wanted a piece of the pie. Graft, bribes, payoffs, you name it. You think I embezzled a lot? Shit, that’s nothing compared to what I had to pay in bribes just to build a solar plant in the middle of fucking nowhere.”

“And then?” Stratt said.

He looked at his shoes. “We built a pilot plant—one square kilometer of mirror area. All of it focused on a large metal drum full of water on top of a tower. Boil the water, run a turbine, you know the drill. I had a crew checking the drum for leaks. When anyone’s in the tower, the mirrors are supposed to be angled away. But someone in the control room fired up the whole system when they thought they were starting a virtual test.”

He sighed. “Seven people. All dead in an instant. At least they didn’t suffer. Much. Someone had to pay. The victims were all New Zealanders, and so am I. So the government came after me. It was a farce of a trial.”

“And the embezzlement?” I said.

He nodded. “Yeah, that came up in the trial too. But I would have gotten away with it if the project had been successful. I’m not to blame here. I mean, yeah, stealing money, okay, I’m guilty of that. But I didn’t kill those people. Not through negligence or any other means.”

“Where were you when the accident happened?” Stratt said.

He paused.

“Where were you?” she repeated.

“I was in Monaco. On a vacation.”

“You’d been there for three months on that vacation. Gambling away your embezzled money.”

“I…have a gambling problem,” he said. “I admit that. I mean, it was gambling debt that made me embezzle in the first place. It’s a sickness.”

“And what if you had been doing your job instead of going on a bender for three months? What if you’d been there the day the accident happened? Would the accident still have happened?”

His expression was answer enough.

“Okay,” Stratt said. “Now we’re past the excuses and bullshit. You’re not going to convince me you’re an innocent scapegoat. And now you know that. So let’s move on: Tell me about blackpanels.”

“Yeah, okay.” He composed himself. “I’ve spent my whole life in the energy sector, so obviously Astrophage is really interesting to me. A storage medium like that—man, if it weren’t for what it’s doing to the sun, it would be the greatest stroke of luck for humanity in history.”

He shifted in his seat. “Nuclear reactors, coal plants, solar thermal plants…in the end they all do the same thing: Use heat to boil water, use the steam to drive a turbine. But with Astrophage, we don’t need any of that crap. It turns heat directly into stored energy. And it doesn’t even need a big heat differential. Just anything above 96.415 degrees.”

“We know that,” I said. “I’ve been using a nuclear reactor’s heat to breed up Astrophage for the last several months.”

“What’d you get? Maybe a few grams? My idea can get you a thousand kilograms per day. In a few years you’ll have enough for the whole Hail Mary mission. It’ll take you longer than that to build the ship anyway.”

“All right, you have my attention,” I said. Of course, Stratt hadn’t told me anything about whatever “blackpanel” was.

“Get a square of metal foil. Pretty much any metal will do. Anodize it until it’s black. Don’t paint it—anodize it. Put clear glass over it and leave a one-centimeter gap between the glass and the foil. Seal the edges with brick, foam, or some other good insulator. Then set it out in the sun.”

“Okay, what good will that do?”

“The black foil will absorb sunlight and get hot. The glass will insulate it from outside air—any heat loss has to pass through the glass, and that’s slow. It’ll reach an equilibrium temperature well over one hundred degrees Celsius.”

I nod. “And at that temperature you can enrich Astrophage.”

“Yes.”

“But it would be ridiculously slow,” I said. “If you had a one-square-meter box and ideal weather conditions…say, one thousand watts per square meter of solar energy…”

“It’s about half a microgram per day,” he said. “Give or take.”

“That’s a far cry from ‘a thousand kilograms’ per day.”

He smiled. “It’s just a matter of how many square meters you make of it.”

“You’d need two trillion square meters to get a thousand kilograms per day.”

“The Sahara Desert is nine trillion square meters.”

My jaw dropped open.

“That went by fast,” said Stratt. “Explain.”

“Well,” I said. “He wants to pave a chunk of the Sahara Desert with blackpanels. Like…a quarter of the entire Sahara Desert!”

“It’d be the biggest thing ever made by humanity,” he said. “It’d be starkly visible from space.”

I glared at him. “And it would destroy the ecology of Africa and probably Europe.”

“Not as much as the coming ice age will.”

Stratt held up her hand. “Dr. Grace. Would it work?”

I fidgeted. “Well, I mean…it’s a sound concept. But I don’t know if it’s even possible to implement. This isn’t like making a building or a road. We’re talking about literally trillions of these things.”

Redell leaned in. “That’s why I designed the blackpanels to be made entirely out of foil, glass, and ceramics. All materials we have plenty of here on Earth.”

“Wait,” I said. “How do the Astrophage breed in this scenario? Your blackpanels will enrich them, sure, and they’ll be breed-ready. But there are a bunch of steps they need to go through when they breed.”

“Oh, I know.” He smirked. “We’ll have a static magnet in there to give them a magnetic field to follow—they need that to kick off their migration response. Then we’ll have a small IR filter on one part of the glass. It’ll only let the CO₂ IR spectral signature wavelengths through. The Astrophage will go there to breed. Then, after dividing, they’ll head toward the glass because that’s the direction of the sun. We’ll have a small pinhole somewhere in the side of the panel for air exchange with the outside. It’ll be slow enough that it doesn’t cool down the panel, but fast enough to replenish the CO₂ used by Astrophage while breeding.”

I opened my mouth to protest, but I couldn’t find anything wrong with it. He’d thought it all through.

“Well?” said Stratt.

“As a breeder system it’s horrible,” I said. “Way less efficient and far lower yield than my system on the carrier’s reactor. But he didn’t design it for efficiency. He designed it for scalability.”

“That’s right,” he said. He pointed to Stratt. “I hear you have godlike authority over pretty much the whole world right now.”

“That’s an exaggeration,” she said.

“Not much of one, though,” I said.

Redell continued. “Can you get China to orient their industrial base around making blackpanels? Not just them but pretty much every industrial nation on Earth? That’s what it would take.”

She pursed her lips. After a moment, she said, “Yes.”

“And can you tell the goddamned corrupt government officials in North Africa to stay out of the way?”

“That part will be easy,” she said. “When this is all over, those governments will keep the blackpanels. They’ll be the industrial-energy powerhouse of the world.”

“See, there we go,” he said. “Save the world and permanently lift Africa out of poverty while we’re at it. Of course, this is all just a theory. I have to develop the blackpanel and make sure we can mass-produce it. I’d need to be in a lab instead of prison.”

Stratt mulled it over. Then she stood.

“Okay. You’re with us.”

He pumped his fist.

I wake up in my bed, which is mounted to the tunnel wall. That first night was a kludge with duct tape. Since then, I learned that epoxy glue works well on xenonite, so I was able to attach a couple of anchor points and mount the mattress properly.

I sleep in the tunnel every night now. Rocky insists. And, once every eighty-six hours or so, Rocky sleeps in the tunnel and wants me to watch. Well, he’s only slept three times so far, so my data on his waking period is a bit sparse. But he’s been kind of consistent on it.

I stretch out my arms and yawn.

“Good Morning,” Rocky says.

It’s pitch-dark. I turn on the lamp mounted next to the bed.

Rocky has an entire workshop set up on his side of the tunnel. He’s always making modifications or repairs to something or other. Seems like his ship is constantly in need of repair. Right this moment he holds an oblong metal device with two of his hands and uses another two to poke at the innards with needle-like tools. The remaining hand grasps a handle on the wall.

“Mornin’,” I say. “I’m going to eat. I’ll be back.”

Rocky waves absently. “Eat.”

I float down to the dormitory for my morning ritual. I eat a prepackaged breakfast (scrambled eggs with pork sausage) and a bag of hot coffee.

It’s been a few days since I last cleaned up, and I can smell my own body odor. Not a good sign. So I sponge off at the sponge-bath station and get a clean jumpsuit. All this technology and I haven’t seen any means of cleaning clothing. So I’ve taken to soaking it in water and putting it in the lab freezer for a while. Kills off all the germs, and those are what cause the smell. Fresh, not-clean clothes.

I pull the jumpsuit on. I’ve decided today is the day. After a week of honing our language skills, Rocky and I are ready to start having real conversations. I can even understand him without having to look at the translation about a third of the time now.

I float back to the tunnel, sipping the last of my coffee.

Okay. Finally I think we have the words needed for this discussion. Here goes.

I clear my throat. “Rocky. I am here because Astrophage makes Sol sick but doesn’t make Tau Ceti sick. Are you here for the same reason?”

Rocky puts the device and his tools on his bandoleer and climbs along the support rails to the divider. Good. He understands this is a serious conversation.

“Yes. No understand why Tau not sick but Eridani is sick. If Astrophage no leave Eridani, my people die.”

“Same!” I say. “Same same same! If Astrophage continues to infect Sol, all the humans will die.”

“Good. Same. You and me will save Eridani and Sol.”

“Yes yes yes!”

“Why did other humans on you ship die, question?” Rocky asks.

Oh. So we’re going to talk about that?

I rub the back of my head. “We, uh…we slept all the way here. Not a normal sleep. A special sleep. A dangerous sleep, but necessary. My crewmates died, but I didn’t. Random luck.”

“Bad,” he says.

“Bad. Why did the other Eridians die?”

“I not know. Everyone get sick. Then everyone die.” His voice quavers. “I not sick. I not know why.”

“Bad,” I say with a sigh. “What kind of sick?”

He thinks for a moment. “I need word. Small life. Single thing. Like Astrophage. Eridian body made of many many of these.”

“Cell,” I say. “My body is many many cells also.”

He says the Eridian word for “cell,” and I add the tones to my ever-growing dictionary.

“Cell,” he says. “My crew have problem with cells. Many many cells die. Not infection. Not injury. No reason. But not me. Never me. Why, question? I not know.”

Each individual cell in the affected Eridians died? That sounds horrible. It also sounds like radiation sickness. How am I going to describe that? I shouldn’t have to. If they’re a spacefaring people, they should already understand radiation. We don’t have a word for it between us yet, though. Let’s work on that.

“I need a word: fast-moving hydrogen atoms. Very very fast.”

“Hot gas.”

“No. Faster than that. Very very very fast.”

He wiggles his carapace. He’s confused.

I try another approach. “Space has very very very fast hydrogen atoms. They move almost the speed of light. They were created by stars long long long ago.”

“No. No mass in space. Space is empty.”

Oh boy. “No, that’s wrong. There are hydrogen atoms in space. Very very fast hydrogen atoms.”

“Understand.”

“You didn’t know that?”

“No.”

I stare in shock.

How can a civilization develop space travel without ever discovering radiation?

“Dr. Grace,” she said.

“Dr. Lokken,” I said.

We sat across from each other at a small steel table. It was a tiny room, but spacious by aircraft-carrier standards. I didn’t quite understand its original purpose and its name was written in Chinese characters. But I think it was a place for the navigator to look at charts…?

“Thank you for making time to see me,” she said.

“Not a problem.”

As a rule, we tried to avoid each other. Our relationship had matured from “annoyed with each other” to “very annoyed with each other.” I was as much a part of the problem as she was. But we got off on the wrong foot all those months ago back in Geneva and never really improved.

“Of course, I don’t think this is necessary.”

“Neither do I,” I said. “But Stratt insisted you run this stuff by me. So here we are.”

“I have an idea. But I want your opinion.” She pulled out a file and handed it to me. “CERN is going to release this paper next week. This is a rough draft. But I know everyone there, so they let me see an advance copy.”

I opened the folder. “Okay, what’s it about?”

“They figured out how Astrophage stores energy.”

“Really?!” I gasped. Then I cleared my throat. “Really?”

“Yes, and frankly it’s amazing.” She pointed to a graph on the first page. “Long story short: It’s neutrinos.”

“Neutrinos?” I shook my head. “How the heck…”

“I know. It’s very counterintuitive. But there’s a large neutrino burst every time they kill an Astrophage. They even took samples to the IceCube Neutrino Observatory and punctured them in the main detector pool. They got a massive number of hits. Astrophage can only contain neutrinos if it’s alive, and there’s a lot of them in there.”

“How does it make neutrinos?”

She flipped a few pages in the paper and pointed to another chart. “This is more your area than mine, but microbiologists have confirmed Astrophage has a lot of free hydrogen ions—raw protons with no electron—zipping around just inside the cell membrane.”

“Yeah, I remember reading about that. It was a group in Russia that found that out.”

She nodded. “CERN is pretty sure that, through a mechanism we don’t understand, when those protons collide at a high enough velocity, their kinetic energy is converted into two neutrinos with opposite momentum vectors.”

I leaned back, confused. “That is really odd. Mass usually doesn’t just ‘happen’ like that.”

She wiggled her hand. “Not quite true. Sometimes gamma rays, when they pass close to an atomic nucleus, will spontaneously become an electron and a positron. It’s called ‘pair production.’ So it’s not unheard-of. But we’ve never seen neutrinos created that way.”

“That’s kind of neat. I never got too deep into atomic physics. I’ve never heard of pair production before.”

“It’s a thing.”

“Okay.”

“Anyway,” she said, “there’s a lot of complicated stuff about neutrinos I won’t get into—there are different kinds and they can even change what kind they are. But the upshot is this: They’re an extremely small particle. Their mass is something like one twenty-billionth the mass of a proton.”

“Waaaaaait,” I said. “We know Astrophage is always 96.415 degrees Celsius. Temperature is just the velocity of particles inside. So we should be able to calcu—”

“Calculate the velocity of the particles inside,” she said. “Yes. We know the average velocity of the protons. And we know their mass, which means we know their kinetic energy. I know where you’re going with this and the answer is yes. It balances.”

“Wow!” I put my hand on my forehead. “That’s amazing!”

“Yes. It is.”

That was the answer to the long-asked question: Why is Astrophage’s critical temperature what it is? Why not hotter? Why not colder?

Astrophage makes neutrinos in pairs by slamming protons together. For the reaction to work, the protons need to collide with a higher kinetic energy than the mass energy of two neutrinos. If you work backward from the mass of a neutrino, you know the velocity those protons have to collide at. And when you know the velocity of particles in an object, you know its temperature. To have enough kinetic energy to make neutrinos, the protons have to be 96.415 degrees Celsius.

“Oh man,” I said. “So any heat energy above the critical temperature will just make the protons collide harder.”

“Yes. They’ll make neutrinos and have leftover energy. Then they bump into other protons, et cetera. Any heat energy above the critical temperature gets quickly converted into neutrinos. But if it drops below critical temperature, the protons are going too slow and neutrino production stops. End result: You can’t get it hotter than 96.415 degrees. Not for long, anyway. And if it gets too cold, the Astrophage uses stored energy to heat back up to that temperature—just like any other warm-blooded life-form.”

She gave me a moment to let that all sink in. CERN really came through. But a couple of things still bothered me.

“Okay, so it makes neutrinos,” I said. “How does it turn them back into energy?”

“That’s the easy part,” she said. “Neutrinos are what’s called Majorana particles. It means the neutrino is its own antiparticle. Basically, every time two neutrinos collide, it’s a matter-antimatter interaction. They annihilate and become photons. Two photons, actually, with the same wavelength and going opposite directions. And since the wavelength of a photon is based on the energy in the photon…”

“The Petrova wavelength!” I yelped.

She nodded. “Yes. The mass energy of a neutrino is exactly the same as the energy found in one photon of Petrova-wavelength light. This paper is truly groundbreaking.”

I rested my chin on my hands. “Wow…just wow. I guess the only remaining question is how does an Astrophage keep neutrinos inside?”

“We don’t know. Neutrinos routinely pass through the entire planet Earth without hitting a single atom—they’re just that small. Well, it’s more about quantum wavelengths and probabilities of collision. But suffice it to say, neutrinos are famously hard to interact with. But for some reason, Astrophage has what we call ‘super cross-sectionality.’ That’s just a fancy term meaning nothing can quantum-tunnel through it. It goes against every law of particle physics we thought we knew, but it’s been proven over and over.”

“Yeah.” I tapped my finger on the table. “It absorbs all wavelengths of light—even wavelengths that should be too large to interact with it.”

“Yes,” she said. “Turns out it also collides with all matter that tries to get by, no matter how unlikely that collision should be. Anyway, as long as an Astrophage is alive, it exhibits this super cross-sectionality. And that brings us nicely to what I wanted to talk to you about.”

“Oh?” I said. “There’s more?”

“Yes.” She pulled a diagram of the Hail Mary hull out of her bag. “This is what I need you for: I’m working on radiation protection for the Hail Mary.”

I perked up. “Of course! Astrophage will block it all!”

“Maybe,” she said. “But I need to know how space radiation works to be sure. I know the broad strokes, but not the details. Please enlighten me.”

I folded my arms. “Well, there’s two kinds, really. High-energy particles emitted by the sun, and GCRs that are just kind of everywhere.”

“Start with the solar particles,” she said.

“Sure. Solar particles are just hydrogen atoms emitted by the sun. Sometimes a magnetic storm on the sun can cause it to spit out a whole bunch of them. Other times it’s relatively quiet. And lately, the Astrophage infection has been robbing so much energy from the sun that magnetic storms are less common.”

“Horrifying,” she said.

“I know. Did you hear that global warming has been almost undone?”

She nodded. “Humanity’s recklessness with our environment accidentally bought us an extra month of time by pre-heating the planet.”

“We fell in poop and came out smelling like roses,” I said.

She laughed. “I have not heard that one. We don’t have that expression in Norwegian.”

“You do now.” I smiled.

She looked down at the hull plan—a little faster than I think was necessary, but whatever.

“How fast do these solar particles travel?” she asked.

“About four hundred kilometers per second.”

“Good. We can ignore them.” She scribbled a note to herself on the paper. “The Hail Mary will be going away faster than that within eight hours. They won’t be able to catch up, let alone do any damage.”

I whistled. “It’s really amazing what we’re doing. I mean…jeez. Astrophage would be the best thing ever if it weren’t, you know, destroying the sun.”

“I know,” she said. “Now, tell me about GCRs.”

“Those are trickier,” I said. “It stands for—”

“Galactic cosmic rays,” she said. “And they’re not cosmic rays, right?”

“Right. They’re just hydrogen ions—protons. But they’re going a lot faster. They’re going near the speed of light.”

“Why are they called cosmic rays if they’re not even electromagnetic emissions?”

“People used to think they were. The name stuck.”

“Do they come from some common source?”

“No, they’re omnidirectional. They’re made by supernovas, which have happened all over the place. We’re just kind of constantly awash with GCRs in all directions. And they’re a huge problem for space travel. But not anymore!”

I leaned forward to look at her schematic again. It was a cross-section of a hull. There was a 1-millimeter void between two walls. “Are you going to fill that area with Astrophage?”

“That’s the plan.”

I pondered the schematic. “You want to fill the hull with fuel? Isn’t that dangerous?”

“Only if we let it see CO₂-band light. If it doesn’t see CO₂, it won’t do anything. And it’ll be in the dark between the hulls. Dimitri plans to make a fuel slurry out of Astrophage and low-viscosity oil to make it easier to transport to the engines. I want to line the hull with that stuff.”

I pinched my chin. “It could work. But Astrophage can die from physical trauma. You can kill one by poking it with a sharp nanostick.”

“Yes, that’s why I asked CERN to do some off-the-books experiments for me as a favor.”

“Wow. CERN will just do whatever you want? Are you, like, mini-Stratt or something?”

She chuckled. “Old friends and contacts. Anyway, they found that even particles moving near light speed can’t get past Astrophage. And none of them seem to kill it either.”

“That actually makes a lot of sense,” I said. “It evolved to live on the surface of stars. They must get bombarded by energy and very fast-moving particles all the time.”

She pointed to a zoomed-in schematic of Astrophage canals. “The entire radiation load will be halted. All we need is a layer of Astrophage slurry thick enough to guarantee there’s always an Astrophage cell in the way of any incoming particles. One millimeter should be more than enough. Plus, we don’t waste any mass. We’ll be using the fuel itself as insulation. And if the crew need that last little bit of Astrophage, well, consider it a reserve.”

“Hmm…a ‘reserve’ that could power New York City for twenty thousand years.”

She looked at the diagram, then back to me. “You did all that math in your head?”

“Eh, I had some shortcuts. We’re dealing with such absurd scales of energy here, I tend to think in ‘New York City years’ of energy, which is about one-half of one gram of Astrophage.”

She rubbed her temples. “And we need to make two million kilograms of it. If we make a mistake along the way…”

“We’ll save Astrophage the trouble of destroying humanity by doing it ourselves,” I say. “Yeah. I think about that a lot.”

“So, what do you think?” she said. “Is this a terrible idea, or could it work?”

“I think it’s genius.”

She smiled and looked away.