It's hard to find hopeful sci-fi these days. The zeitgeist is that things are bad and they will keep getting worse. That's a problem, because before you can build a better future, you must first imagine one. This is the first book I've found in a long time that does a credible job of that.

This post is about a pair of novels by Daniel Suarez. The first one is Delta-V, the physics term for a change in velocity; the second one is called Critical Mass. Together they're a heavily-researched look at asteroid mining, offworld economics, and space-based solar power.

The series takes place in the mid 2030s. By this point, the symptoms of climate change are becoming serious, creating what people call "the Long Emergency": famines, storms, and waves of climate refugees. There is real concern that the global economy will collapse under the strain. To avert financial apocalypse, an expedition is launched to mine the asteroid Ryugu; the first book covers the miners' training, their long journey through space, and the hazards of mining an asteroid in deep space. In the second book, they use those mined materials to build a space station in lunar orbit, to set up a railgun for launching materials from the moon's surface into its orbit, and to begin building the first space-based solar power satellites.

I was surprised to learn that space-based solar power is a real thing that the US, China, and several other countries and companies are actively pursuing. Basically, you have a bunch of solar panels in orbit, which beam power down to receiving antennas ("rectennas") on Earth. You lose a lot of efficiency converting the electricity to microwaves and back, but solar panels on orbit have access to ~7-10x more energy than those on the ground, since there's no atmosphere in the way and it's always solar noon. In exchange for a large initial investment, space-based solar power offers always-on, 100% renewable energy that can be switched from New York to California at a moment's notice.

That initial investment is a doozy, though. SpaceX is working on lowering launch costs, but launching material from Earth's surface into orbit is going to be very expensive for a very long time. So these books look at what might be possible if we could avoid those costs. What if we could create mining and manufacturing operations in space? What if we could use those to generate clean power in heretofore undreamt-of amounts?

I’m going to excerpt a conversation from the second book:

[At dinner,] chemist Sofia Boutros described the unfolding water crisis in the Nile watershed back on Earth—and the resulting regional conflict. This elicited from around the table a litany of other climate-change-related calamities back home, from wildfires, to floods, to famines, to extinctions.

The Russian observer, Colonel Voloshin, usually content to just listen, chimed in by saying, "Nations which have contributed least to carbon emissions suffering worst effects." He looked first to Lawler and then Colonel Fei. "Perhaps the biggest polluters should pay reparations."

Dr. Ohana looked down the table toward him. "It's my understanding that Russia has actually benefitted from warmer climate."

Yak replied instead. "Not overall. Soil in Siberia is poor. Wildfires and loss of permafrost also disruptive."

Lawler added. "You guys sell plenty of fossil fuels, too, Colonel."

The electrical engineer, Hoshiko Sato, said, "Complete decarbonization is the only way to solve climate change."

Most of the group groaned in response.

She looked around the table. "That might sound unrealistic, but there's no other choice if we want to save civilization."

Chindarkar said, "We've been saying the same thing for fifty years, Hoshiko. It's barely moved the needle."

"We’ve brought carbon emissions down considerably since 2020."

Boutros said, "You mean we slowed their growth."

Ohana said, "We should be planting more trees."

Monica Balter countered, "Trees require water and arable land. Climate change is causing deserts to spread, pitting food versus trees. Plus, whatever carbon a tree captures gets released when it dies—which could happen all at once in a wildfire."

Chindarkar looked down the table at her. "Nathan Joyce claimed we could use solar satellites to power direct carbon capture. Could that really be done at the scale necessary to reduce global CO2 levels?"

Colonel Voloshin let out a laugh. "That's not even in the realm of possibility. It wouldn't even make a dent."

Monica Balter said, "I respectfully disagree, Colonel." She looked to Boutros. "And Sofia, I understand we must do everything possible down on Earth to reduce carbon emissions: solar panels, wind turbines, geothermal—all of it. But that won't remove what's already in the atmosphere."

Voloshin shook his head. "We must adapt."

Lawler couldn't resist. "Easy for Russia to say."

Balter spoke to Voloshin. "Back in 1850, atmospheric carbon was at two hundred eighty parts per million. Now it's at four hundred fifty-seven parts per million. We put over a trillion tons of CO2 into Earth's atmosphere over that time. Humans caused the problem, and humans can solve it."

The colonel was unfazed. "Yes. All of humanity worked hard to cause this, and it still required almost two centuries to accomplish. It is naïve to think a few machines will correct it."

"Half of that excess carbon was emitted in the last forty years, and direct air carbon capture powered by solar satellites can actually work at a global scale. I can show you the numbers, if you like."

He scoffed. "Even billionaire Jack Macy says that solar power satellites are idiotic—that very little energy beamed from space reaches the terrestrial power grid due to transmission and conversion losses."

Balter nodded. "The number is 9 percent."

The crew around the table murmured.

He spread his hands. "I rest my case."

"But 9 percent of what? Jack Macy neglects to mention that a solar panel up in orbit is seven times more productive than one on the Earth's surface. The fact that he runs a rooftop solar company might have something to do with that.

Boutros asked, "A sevenfold difference just from being in space?"

Balter turned to her. "The best you can hope for on the Earth's equator at high noon is 1,000 watts of energy per square meter—and that's without factoring in nighttime, cloudy days, seasons, latitude. But a power sat in geosynchronous orbit would almost always be in 1,368 watts of sunlight per square meter. So you get a whole lot more energy from a solar panel in space even after transmission inefficiencies are factored in. Plus, a power sat won't be affected by unfolding chaos planetside."

Voloshin shrugged. "What if it is cloudy above your rectenna? You would not be able to beam down energy."

"Not true. We use microwaves in the 2.45-gigahertz range. The atmosphere is largely invisible at that frequency. We can beam the energy down regardless of weather—and directly to where it's needed. No need for long distance power lines."

"But to what purpose? It could not be done on a scale sufficient to impact Earth."

"Again, I could show you the numbers."

Chindarkar said, "I'd like to see them, Monica. Please."

Balter put down her fork and after searching through virtual UIs for a moment, put up a shared augmented-reality screen that appeared to float over the end of the table on the station's common layer. It displayed an array of numbers and labels. "Sorry for the spreadsheet."

Colonel Fei said, "We are quite interested in seeing it, Ms. Balter."

She looked to the faces around the table. "There are four reasons I got involved in space-based solar power... " She pealed them off on her fingers. "...electrification, desalination, food generation, and decarbonization. First: electricity. We all know the environmental, economic, and political havoc back on Earth from climate change. Blackouts make that chaos worse, but a 2-gigawatt solar power satellite in geosynchronous orbit could instantly transmit large amounts of energy anywhere it's needed in the hemisphere below it. Even several locations at once. All that's needed is a rectenna on the ground, and those are cheap and easy to construct."

Chindarkar nodded. "We saw one on Ascension Island."

Jin added, "J.T. and I are building sections of the lunar rectenna. It is fairly simple."

"Right. For example, space-based energy could be beamed to coastal desalination plants in regions suffering long-term drought-providing fresh water. It can also be used to remove CO2 directly from seawater, through what's known as single step carbon sequestration and storage, converting the CO2 into solid limestone and magnesite—essentially seashells. This would enable the oceans themselves to absorb more atmospheric CO2. Or we could power direct air capture plants that pull CO2 straight out of the atmosphere."

Voloshin interjected. "Again, a few satellites will not impact Earth's atmospheric concentrations, and where would you sequester all this CO2?"

"Just a few satellites wouldn't impact climate, no—but there's definitely a use for the CO2—in creating food. Droughts in equatorial zones are causing famine, but hydrogenotrophic bacteria can be used to make protein from electricity, hydrogen, and CO2. The hydrogen can be electrolyzed from seawater and CO2 from the air. All that's needed is clean energy." She glanced to Chindarkar. "NASA first experimented with this in the 1960s as a means for making food here in deep space."

"Really? Even back then."

"The bioreactor for it is like a small-batch brewery. You feed in what natural plants get from soil: phosphorus, sulfur, calcium, iron, potassium—all of which, incidentally, can be extracted from lunar regolith. But I digress..."

Colonel Fei's eyebrows raised. "That is indeed interesting."

"The bioreactor runs for a while, then the liquid is drained and the solids dried to a powder that contains 65 percent protein, 20 to 25 percent carbohydrates, and 5 percent fatty acids. This can be made into a natural food similar to soy or algae. So with energy, CO2, and seawater, we could provide life-saving nutrition just about anywhere on the planet via solar power satellites."

Voloshin was unimpressed. "Yet it would still not resolve climate change."

"At scale it could. Do the math ... " Balter brought up her spreadsheet. "We're emitting 40 billion tons of CO2 per year, 9 billion tons of which can't be sequestered by the natural carbon cycle and which results in an annual increase of roughly two parts per million atmospheric CO2—even after decades of conservation efforts."

She tapped a few screens and a virtual image of an industrial structure covered in fan housings appeared. "A direct air capture facility like this one could pull a million tons of CO2 out of the atmosphere each year at a cost of one hundred dollars a ton. All of the components are off-the-shelf and have existed for decades. Nothing fancy. But it needs 1.5 megawatts of constant clean energy to power it—and that's where solar power satellites come in."

Voloshin said, "But who would pay? Governments? Do not count on this."

Chindarkar asked, "Monica, seriously: How many carbon capture plants would it take to make a difference in the atmosphere of the entire Earth?"

Jin added, "And how many solar power satellites to power them?"

Balter brought her spreadsheet back up. "Merely to cancel out Earth's excess annual emissions—9 billion tons of CO2—we'd need nine thousand 1-megaton DAC plants worldwide, each requiring 150 to 300 acres."

The group groaned.

Tighe said, "That's a lot of hardware and a lot of real estate, Monica."

"It doesn't have to be on land. Just 2.7 million acres total—smaller than Connecticut. And that would be spread across the entire globe. More importantly, doing that stops the advance of climate change. If we reduce emissions, then it would actually help reverse climate change."

Chindarkar studied the numbers. "Powered by how many solar satellites?"

Balter highlighted the number. "It would take 1.6 terawatts of electricity—or 818 2-gigawatt SPS-Alphas. Each about 7,400 tons. But again: that halts the advance of climate change."

The group groaned again.

"Eight hundred eighteen satellites?" Jin shook his head. "That would take decades to build."

"Not with automation and sufficient materials here on orbit. You've seen the SPS-Alpha I'm building—it's made of simple, modular components."

"Yours is one-fortieth the size of these 7,400-ton monsters."

"But it's the same design. We just need the resources up here in space, and we could scale it rapidly with automation."

Voloshin picked up his fork. "As I said: it is a technological fantasy."

Chindarkar ignored him. "Monica, what would it require to not just halt climate change—but reverse it?"

Balter clicked through to another screen. "To return Earth to a safe level—say, three hundred fifty parts per million CO2-you'd need to pull three-quarters of a trillion tons out of the atmosphere." She made a few changes to her model. "So with forty thousand DAC plants, powered by thirty-six hundred 2-gigawatt satellites in geosynchronous orbit, you could accomplish that in eighteen years."

Fei asked, "At what cost?"

"Roughly seventy-two trillion dollars."

Again groans and an impressed whistle.

Voloshin shook his head. "I told you."

Balter added, "That's four trillion a year, over eighteen years. Spread across the entire population of Earth."

This was met with a different reaction.

Jin said, "That is actually less than I thought."

"And bear in mind the fossil fuel industry has been supported by half a trillion dollars in direct government subsidies worldwide every year for ages. Whereas this four trillion is for just a limited time and would permanently solve climate change, and we'd see significant climate benefits within a decade as CO2 levels came down. And once it was accomplished, all that clean energy could be put toward other productive uses, either on Earth or in space."

She studied the faces around her. "But to accomplish it, we'd need tens of millions of tons of mass in orbit. Launching all that mass up from Earth would never work because all those rockets would damage the atmosphere, too. However, with your lunar mass-driver—and the ones that follow it—we could make this work. This is why I'm here."

Those around the table pondered this. For the moment, even Voloshin was silent.

Boutros asked, "Is it not risky to tinker with the Earth's atmosphere?"

"That's what we're doing now, Sofia. This would just reverse what we've done and return Earth to the conditions we evolved in."

Chindarkar pointed to the virtual spreadsheet. "Does that seventy-two trillion dollars include the cost of the solar power satellites?"

"Yes. And doing nothing will cost us far more. Best estimates are that by the year 2100, continued climate change will reduce global GDP by 20 percent—which is about two thousand trillion dollars. Not to mention the cost of possibly losing civilization.

"But if, as your CEO Mr. Rochat says, we intend to prove the SPS concept at scale here in lunar orbit, well... then you will make this commercially feasible. In other words, you can make this future happen. Everyone else has talked it to death. The bean counters and decision makers back on Earth clearly won't do it, no matter how critical it is. And this needs to be started as soon as possible—before the situation on Earth gets truly untenable."

This book is not afraid to think big. That's what sci-fi is for, right? And it's extensively researched; there's a bibliography at the end of each book that I've used to start my own research journeys.

I like these books because they're ambitious. They never downplay the scale of the problems we face, but they maintain that these problems are solvable, and they expose me to new ideas I'd never heard of. I found them in my local library. Thanks for reading this wall of text!