Two-Planet Economy
Adam Kall, Director of Science
4 minute read
I’ve always loved megastructures and massive infrastructure projects. Something about humans deciding to hold back the Colorado River, build a railroad across Eurasia, or land on the Moon strikes me as awesome and awe-inspiring. Naturally, I wish humanity would take on more of these projects with increasing frequency, so I had to try and understand why humans do things, both big and small. As it turns out, most human megaprojects are undertaken for one of three reasons: for a religious purpose, a military advantage, or an economic benefit. I personally can’t predict what megaprojects the world’s religious will inspire in the future, nor am I an expert on military theory and what will or will not give a decisive combat advantage in the future, but I am able to use the lens of economic benefits to explore my favorite megaproject, colonizing space.
The first thing to establish when describing a two-planet economy is just how far away they would be from each other. Not only that, the distance would change with periods of relative closeness and periods of nearly impossible travel. For the sake of not having this entire column be abstract I’ll examine Mars specifically as the second planetary economy. Mars has a 780 day synodic period, or the time it takes for Mars to return to the same relative position of the Earth and Sun. This means every 2.5 years there will be a window that is ideal for shipping goods and another window when shipping goods is incredibly difficult (when the efficient transfer orbit passes right through the middle of the sun it is no longer ideal). This would create an economy and trade relationship with Earth built around 2.5 year plans, where a ton of activity and productivity is spent preparing for those few months when a flurry of ships are launched to Earth and return to Mars with their precious cargo. This of course begs the question of what these ships would be transporting.
From Earth the most obvious export will be food, as even with climate change having a dramatic effect on our biosphere, it is still much easier to mass produce food in a place with liquid water, moderate temperatures, and air to breathe. There are water resources on Mars, so this food would likely be dehydrated to save on mass and volume. Earth would also supply the majority of the human workforce to Mars, in addition to any hydrocarbon-based products like kerosene or plastic (if oil is discovered on Mars that would dramatically change a lot of things). Beyond that, it will be in the Martian economy’s best interest to produce things like consumer goods and electronics on the planet as the raw metals are available in spades.
Raw materials are actually what Mars will be able to specialize in. Unlike on Earth where a big hole in the ground is considered an ecological disaster, Mars is a great big dead desert with a massive number of craters that will jump-start the excavation process. Gravity on Mars is only about ⅓ standard Earth gravity, so imagine excavators and dump trucks three times larger than those that exist on Earth. This raw material would be too heavy to launch on its own, so processing and smelting of the ore would also occur in the Martian economy. As the Martian atmosphere is very thin compared to Earth it would take less effort to precisely control the atmosphere inside the metallurgical facilities, ensuring just the right amount of oxidation can occur. Whether the smelted metals are then turned into final products depends on the ability to automate the production lines and the actual cost of shipping.
Mars also has massive advantages when it comes to shipping whatever end products are manufactured off-world. Due to there being less gravity and less atmosphere, a space elevator is a much more achievable possibility on Mars than on Earth. The construction of skyhooks or other interplanetary infrastructure would also reduce the costs to ship. These ships wouldn’t only have to target the Earth as their destination. If they travel up the Sun’s gravity well the asteroid belt is nearby and filled with many rare-earth materials. These asteroids wouldn’t even need to be processed in space, instead they could be redirected to a collision course with Mars and just aim for any part of the abundant empty desert, preferably in the northern hemisphere as it will likely become a giant ocean when the terraforming process begins. Which brings the final question of this column, would it make economic sense to terraform Mars?
So far we’ve established Mars as an industrial juggernaut, likely in a time when many easy-to-reach raw resources on Earth are running out. It is easy to imagine Mars becoming a kind of Forge World from science fiction and establishing itself as the factory for the solar system. I personally believe this is as short-sighted as the imperial empires of the Age of Exploration when they expected the colonies in the New World and Africa to remain the suppliers of raw goods. Those colonies contained people and families living and working, people who grew tired of an overlord many months' journey away, as would be the case with Martians in the future. It feels inevitable that Martians would want independence and higher standards of living, both of which are difficult to achieve when you can’t step outside without asphyxiation. I see Mars becoming terraformed so it can grow its own food and its people enjoy outside walks in the park, evolving its economy into a mature service-based model, not unlike Earth, with the factory planet of the solar system moving to one of the Jovian moons or another rock in the heavens. Only time will tell what reason humanity uses to justify our relentless pursuit of the impossible, but whichever cause it is for, I see a future in which we journey to another planetary body for more than just a passing visit.
Recommended column to read next: The Case for Orbital Industry