The setting for Weir's latest book is a lunar resort town.
The setting for Weir’s latest book is a lunar resort town. Nicolas Thomas/Unsplash

Among science-fiction writers, only a minority strive for accuracy in their depictions of technology, physics, and protagonists being sucked out the bay doors without a fully functioning space suit. Even fewer worry whether the economy of an alien capital makes any sense. But Andy Weir is one such author, and he may make up a group of one.

Weir is best known as the author of The Martian, a novel about a wisecracking, stranded-on-Mars astronaut who was recently played by Matt Damon in a highly plausible movie of the same name. Weir is a former computer programmer who, in his own words, is the type of person who asks questions like “Why does the Federation have starships if they can beam people hundreds of light-years?” and complains that “lunar colonies in sci-fi usually have medium to high levels of bullshit in their economics.”

So, when writing his latest novel, Artemis, Weir put a lot of thought into the economics of his own lunar colony. “Artemis” is the name of the colony, which is a resort town for tourists paying $70,000 for the trip of a lifetime.

That $70,000 figure didn’t come from nowhere—Weir wrote a 10-page paper that describes his economic model of Artemis. (While Weir notes that he had to make assumptions about the development of spacecrafts and space tourism, his efforts won him praise from economist Tyler Cowen.) He also drew on the experiences of real-life astronauts—and the physics and chemistry of brewing coffee in space—to imagine the culinary landscape of the moon in 2080, when his story takes place.

I asked Weir about the quality of space-coffee, why he cares about economics in sci-fi, and the cost of fine dining on the moon. This interview has been edited for clarity and length.

The cover of Weir's new book.
The cover of Weir’s new book. Penguin Random House

The standard food on Artemis is algae, and it doesn’t sound like it tastes very good. Why do you imagine algae as the staple food?

Artemis doesn’t have a large volume—it just can’t afford to grow wheat, barley, potatoes, or any other common staple crop. Importing food from Earth would be cost-prohibitive for most of Artemis’s population. So they grow algae in vats. It’s the most space-efficient way to create human-digestible calories.

Also, chlorella algae (the type used to make “gunk”) is a superfood, providing all the nutrition a human needs. And it has a cool natural feature: It will make more protein or more sugars internally based on the amount of frequencies of light it absorbs. So it can be fine-tuned to be perfect for human consumption.

You have said that you want your books to be scientifically accurate, and that you tried to make the economy of Artemis as realistic as possible, too. Why is it important to you that your fictional world is realistic—all the way down to plausible food prices?

I just try to write stories that I would enjoy. And when I see a fictional society, the first question I ask myself is “How does this society sustain itself?” Without a functional economy, no society can survive. Also, the growth and nature of a city is heavily dependent on where its money comes from. So I wanted to “grow” Artemis in a plausible and reasonable way from the ground up.

One draw of lunar tourism would be visiting historic sites such as the Apollo landing zones.
One draw of lunar tourism would be visiting historic sites such as the Apollo landing zones. Johnson Space Center/Public Domain

One example of your economic modeling is that you tried to determine how much a good Cantonese meal would cost on Artemis in 2080. Which are the biggest factors that determine the price of Earth food on a lunar colony?

Really, there are only two factors that matter: the price of the food on Earth, and the cost of transporting it.

I wrote a 10-page paper on the economics of Artemis and how I arrived at the cost of transporting goods there. But the end result is this: It costs about $160 (in 2015 U.S. dollars) to transport a kilogram of cargo from Earth to Artemis.

It also takes seven days for the cargo to get there. So whatever Cantonese food or cooking ingredients you want to send have to be able to survive in space for that long. They can be frozen or preserved however they normally would be on Earth.

A good Cantonese meal for one at a high-end restaurant in the U.S. will run you about $60. The total dry mass of that meal will be on the order of 500 grams (because of course you’d dehydrate whatever you sent first). So that’s another $80 in transport costs. So a $60 Cantonese meal on Earth would cost you $140 on Artemis.

View of Earth as photographed by the Apollo 8 astronauts on their return trip from the moon.
View of Earth as photographed by the Apollo 8 astronauts on their return trip from the moon. Johnson Space Center/Public Domain

In your book, all the “Earthlings” hate the coffee on Artemis. Why is that, and what would need to change for us to enjoy coffee in space?

The main problem isn’t the moon or space, it’s the atmospheric pressure in Artemis itself. It’s one-fifth the pressure of Earth at sea-level. Perfectly fine for human health, but it has some bad side effects. One problem is that the boiling point of water is 61°C. That temperature makes for tepid coffee and also prevents it from brewing correctly. [On Earth, hot coffee is usually served at temperatures of 71°C or higher.] You could deal with this by brewing the coffee in a pressure-cooker, or by cold-brewing. But no matter what, when you drink it, it’ll have to be 61°C.

Another problem is that your taste buds don’t work quite right at lower pressure. That’s why airline food tastes so bad (in flight, the cabin of an airline is at a much lower pressure than sea level Earth). So Artemis would not be a great place to go if you’re a foodie.

If you made a city on the Moon/Mars/wherever that had a full atmosphere of pressure inside, all those problems would go away. But it adds an unnecessary amount of engineering to fully pressurize vessels.

One option (which I’m probably going to have in a sequel) is to have an entire restaurant that’s in-pressure. You go in, enjoy your delicious meal, then spend four hours decompressing in a chamber.

Would you save Matt Damon from Mars?
Would you save Matt Damon from Mars? 20th Century Fox

Thanks to the success of The Martian, you’ve talked to a number of astronauts and NASA people. Did they give you any insight on what’s different about eating in reduced gravity and what it’s like to eat on the moon?

I did learn a lot about eating in zero gravity. Turns out the experience there is even worse than what Artemisians endure. In zero-g, your sinuses and nose get stuffed up—like having a low-grade cold—because there’s no gravity to pull the fluids down into your throat. So, just as food tastes bland when you have a cold, food tastes bland for astronauts in zero-g. They deal with this mainly by having really flavorful food.

Scientists seem to appreciate your efforts to make your science-fiction novels accurate in terms of the technology. Do you think economists and econ nerds will applaud your efforts to make Artemis’s markets and the lunar-Earth trade realistic?

I have received some positive feedback from my fellow economics geeks. Though econ geeks are far less common than space geeks.

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