To Save Earth We Must Leave It Behind
By: Erasmo Acosta
Tags: Technology, Future, Space, Science, Environment

As our population continues to rise, life on Earth grows increasingly complicated. If human civilization isn’t brought to its knees by a global pandemic or a war, climate change lurks on the horizon — challenging our long-term ability to survive on this little blue marble.

Even discounting gravity, Earth’s environmental conditions appear to be exceptionally rare. If we could replenish Mars’ atmosphere, trying to colonize it will require severe adaptations to the human body — possibly causing the settlers to branch into a different species within generations. But born and raised on Earth, we suffer from a deeply ingrained planetary bias, and settling other worlds reinforce that predisposition.

In the early 70s, American physicist Gerard O’Neill asked his students at Princeton University, “Is a planetary surface the right place for an expanding technological civilization?” Their research convinced O’Neill the answer was a resounding no.

This became the inspiration for his groundbreaking work designing rotating habitats, cylindrical megastructures that perfectly replicate Earth’s gravity and atmospheric conditions, requiring no adaptations to the human body.

Early artist’s conception of the interior of an O’Neill Cylinder. Image Credit: Wikimedia

Taking advantage of 21st century materials, we can construct rotating habitats much bigger than what O’Neill envisioned fifty years ago. Our current population of 7.8 billion people can be comfortably housed inside fewer than 400 of these island-sized rotating megastructures.

A far better option than planets

Our burgeoning civilization would need hundreds of planets to continue growing. But with no other worlds nearby that can support billions of people, we must build them from scratch. In the time it would take to “terraform” Mars, we can construct enough rotating habitats to house billions.

With vast amounts of resources from the sun, we can build new habitats on demand to accommodate the ever-growing human population. As I discuss in a separate article, we can fit more people inside rotating habitats around the sun, than on all habitable planets in our entire galaxy.

“Earth is humanity’s womb! Once it gives birth to a spacefaring civilization, the umbilical cord will be cut. That’s why Mars can’t be a replacement for Earth. Our future lies in space with virtually unlimited energy and room to grow.” — Excerpt from my book K3+

Artist rendition of Proxima b, Earth’s closest exoplanet. Image Credit: ESO/M. Kornmesser

Safe in the hostile vacuum of space

With plenty of power from the sun, AI-controlled lasers will keep these colonies safe from asteroids and other cosmic shrapnel. A layer of soil or water can protect their inhabitants against the solar wind, radiation, and cosmic rays.

It’s also possible to create a magnetic field around the cylinder, using an electromagnet made from coils of superconducting wire. In the cold temperatures of space, electromagnets don’t need to be cooled down to become superconducting. Wires have no electrical resistance and conduct much stronger electrical currents, generating an intense magnetic field.

Closed-loop technologies

Each colony will be a self-sufficient zero-waste ecosystem. On Earth, plants inhale CO2 and exhale oxygen. We can replicate this cycle through closed-loop life support systems to recycle air, like we do onboard the International Space Station.

Crops engineered for higher yields and oxygen production, grown soil-free on vertical farms with aeroponic irrigation, will allow each of these colonies to achieve complete autonomy. Every single aspect of agriculture can be automated, freeing humans to oversee the process, use their creativity to continue innovating, and develop new varietals to satisfy the branching tastes of the growing population.

Image Credit: Wikimedia

Reusing wastewater, making it safe for human consumption, is being pioneered by many cities on Earth. This closed-loop technology can be scaled to deliver an endless supply of drinking water to a space colony. The recycling process also separates precious phosphorus, which is fundamental for agriculture.

But I’m not vegan! I like my steak medium-rare

Although humans can thrive on a plant-based diet, we are innate voracious carnivores — conditioned by millions of years of evolution. According to the fossil record, the big bang of the human mind began when our distant ancestors switched to a meat-based diet.

Today cultured meat is grown in-vitro from clusters of cells, without the need for raising and slaughtering an animal. Although this technology is currently in its infancy, it has the potential within just decades to produce better steaks and countless other animal products — without the need to introduce these living beings to space colonies and sacrifice them.

Genetic enhancements will push the genome to the limit, producing spectacular flavors and textures, while leaving the cruelty of our current farming system far behind.

Image Credit: Erasmo Acosta

“With so many ways collagen crosslinks could be arranged to bind protein, food development was taken a step beyond DNA enhancement. Engineered protein derivates that weren’t purely animal or vegetable anymore, but with irresistible taste and texture, were created.” — Excerpt from my book K3+

Powering a spacefaring civilization

Supplying air, water, food, and other human needs for billions of people in space, will consume colossal amounts of electricity. Imagine the energy consumed by all homes, industries, hospitals, farms, schools — and every other single human activity on Earth you can think of — for an entire year. The sun produces close to 500,000 times as much, in just one second! Let that sink in for a moment.

It’s estimated that solar panels in space can deliver up to 40 times the energy they do on Earth’s surface. Covering the outside of a rotating habitat with photovoltaic cells will generate enough power for its entire population. And direct current (DC) will allow us to build a far more efficient electric system than alternating current (AC) — no need for a bloated and wasteful electric grid, plagued by vulnerabilities.

How do we bring people to these colonies?

We are being held hostages to Earth’s gravitational well. That makes getting people and goods to Low Earth Orbit extremely expensive. However LEO is not nearly free from gravity, but a mirage created by the constant free fall.

Image Credit: Wikimedia

Today, less than 4 percent of a rocket’s mass is actual payload. The rest is fuel and engines, necessary to evade our planet’s captivity, and left behind before reaching LEO. Not feasible for moving billions of people to space colonies, hundreds of thousands of miles away.

Different launch-assist megastructure concepts, without the massive cost and waste of rockets, are feasible with today’s technology. One that particularly excites futurists is the skyhook tether. Also known as a rotovator, this gigantic cartwheeling rod in space will grab ships from the upper stratosphere and swing them up to LEO.

Because skyhooks are a relatively low tech and low cost launch assist mechanism, it’s possible to synchronize a few of them orbiting at different altitudes. Like steps on a ladder, this chain of reusable tethers will deliver balloon raised ships to our space colonies beyond the moon, without burning fuel.

Baby steps

Before we can start building any of these megastructures, entire industries need to be created in space. It will take tens of thousands of rocket launches to deliver the base components for the initial infrastructure. Technologies like 3D printing will be crucial in this effort, but we’ll need to source the materials to be fed to these — and to other construction devices — from space.

Image Credit: Katie Lane (Full distribution rights reserved by Erasmo Acosta)

Mining asteroids and the moon will provide the initial raw materials to put together factories and engineering facilities. After a few decades, it will be possible to construct the first rotating colony — a tiny community of a thousand scientists and engineers to test and improve these technologies in space.

But in order to build dwellings that can house tens of millions each, we’ll need a much larger source of raw materials. The planet Mercury is the leftover rocky core from a past planetary collision, made of 70 percent metals and 30 percent silicates. It has a much higher abundance of metals than Earth, and its low gravity will simplify the extraction.

Taking advantage of 21st century materials, we can construct rotating habitats much bigger than what O’Neill envisioned fifty years ago. Our current population of 7.8 billion people can be comfortably housed inside fewer than 400 of these island-sized rotating megastructures.

Just as our cavern-dwelling ancestors went on to build cities, we will go on to build floating oases around the stars.

Image Credit: Katie Lane (Full distribution rights reserved by Erasmo Acosta)

Our future is bright . . . if we don’t mess it up

We can’t give everyone on Earth a middle-class way of life, without burning our planet to hell — building houses, cars, iPhones, etc. As we cope with a short-term profits system that’s decimating our habitat, the apparent inability of our leaders to act, and the cruelty of life on Earth as a whole, let us not forget that we can build a utopian future in space.

Just as our cavern-dwelling ancestors went on to build cities, we will go on to build floating oases around the stars. Spreading throughout the cosmos will allow us to save the Earth, by leaving it behind.