Geeking Out On Starship Design

Reading Time: 6 minutes

This week on Geek Speaks…Fiction! we welcome science fiction author Patrick S. Tomlinson! Not only is Patrick the author of the brand new book The Ark from Angry Robot Books, he’s also a stand-up comedian and a blogger. Please welcome him to GeekMom!

Hello GeekMom readers! My name is Patrick S. Tomlinson. I’m a sci-fi author and stand-up comedian living in Milwaukee. My debut novel, The Ark, is hitting the shelves November 3rd from Angry Robot Books. I’ve been asked to share what about writing it made me geek out the most.

The Ark was the first novel I’ve written where the plot emerged fully formed. In the span of just a few hours, the outline of all the major plot points and characters filled up my head in a burst of creativity. Over dinner that night, I positively gushed everything I’d come up with to my girlfriend, just to get it out.

As a result, it was also the fastest book I’ve written to date, taking only six months to reach the end, (I’m still not the fastest writer, although I’m getting a lot better). The whole idea behind the book is Earth was destroyed centuries ago, but humanity had just enough time to do something about it. So they built a stupendous generation ship, filled it with fifty-thousand of the planet’s best and brightest, then shot them off for the stars.

Because of this, the world-building for the story was limited to the ship and its occupants, but that didn’t make the task any less daunting. Creating a self-sustaining world in miniature that is believable, compelling, and still scientifically-grounded was a big deal. Just look at the infamous Biodome II experiment to know what I mean.

Image: Angry Robot Books

I spent an awful lot of time researching and tinkering with the environment of the Ark herself. I wanted to get the science as close to right as I could, while incorporating it into the story in the most organic, unobtrusive way possible. I wanted readers to learn about the world through the way the characters interacted with it in their daily lives, how they thought and talked about it, and how its limitations impacted the plot.

The best way to do that was to immerse myself in the ship. Learn about it until it became a real place in my mind. One that I could walk around, observe, and describe just like I could my city. So, first things first, I needed to know what kind of ship it was. Of all the proposals for interstellar ships floating around, there is only one that we could build right now with existing technology: Nuclear Pulse Propulsion, better known as Project Orion.

Basically, what we’re talking about here is a giant nuclear-bomb-shitting pogo stick. The idea is you detonate a series of nukes directly behind the ship, which is protected by a massive ablative plate that both blocks much of the radiation and thermal energy from damaging the ship and its nuggaty human passengers, and acts as a pusher plate to transfer the energy of the bombs into forward momentum. This plate is fixed to the ship by a ring of two-stage shock absorbers, working exactly like the shocks on your car to transfer the force more smoothly to prevent the liquidation of the meatbags inside.

Legend has it that the whole concept for Orion came about after Wernher Von Braun, the imminent German rocket scientist we sort of confiscated from the Nazis, and Robert Oppenheimer, one of the fathers of the atomic bomb, hooked up at a rave and dropped acid, then woke up in the desert outside Vegas three days later surrounded by plans frantically scribbled into bar napkins. The historical accuracy of this legend is dubious at best, but that’s how I chose to believe it happened.

The truly ridiculous thing about this is not only did the physics work, but several different projects run by the Air Force, NASA, and even the British all went well past engineering feasibility studies. So serious were we about building one of these things that not only had scientists designed a shaped-charge nuclear bomb using a uranium containment chamber to maximize the propulsion efficiency of each explosion (because a normal nuke isn’t scary enough) but they actually brought engineers from Coca-Cola into the program as consultants to basically up-size a soda-can vending machine to crap these things out the back of the ship.

So, the Ark would be a Project Orion ship. That dictated the design of her back half. Pusher plate, shock absorbers, a vault for all the nukes, long term storage, reactors, etc. The next question was what to fill her with. After doing a fair amount of reading into genetic diversity, thinking about manpower needed to build a colony, etc, I came up with a number of fifty-thousand people. Not long after, a team of genuine scientists came up with forty-thousand as the minimum “safe” number of people you’d need to cart along to start a new civilization. Gotta admit, I was pretty happy with myself when I read that one.

These 50k folks needed somewhere to live and something to eat, so I dove into things like maximum population density of real cities, minimum acreage of arable land needed to grow food per capita, water requirements, oxygen consumption rates, power requirements, and everything else I could think of that you’d need to keep a medium-sized city worth of people alive for centuries.

It was, unsurprisingly, a lot of shit.

The ship is massive as a result, sixteen kilometers long. It was the smallest I could reasonably make it and still fit everything that it needed to function without replenishment for such a long span of time. After reading into the long term effects of micro-grav on humans, not to mention the plants they would need to eat, I knew the living spaces would need to have artificial gravity of some sort. Being that the story dictated the tech onboard the Ark wasn’t that far advanced of the present day, and Nuclear Pulse Propulsion wouldn’t provide sustained acceleration for the entire trip, that meant giant spinning modules. That meant cylinders. And because of how massive they would be, that meant they had to operate in counter-rotating pairs to cancel out the gyroscopic effects on the rest of the ship.

The mathematic principle that an object’s volume increases exponentially while its surface area increases geometrically dictated that the most efficient arrangement in terms of mass penalty was two gigantic modules.

So everyone lives in two modules, each two kilometers long and two kilometers in diameter. The inside surface of their hulls needed to provide one Earth gravity of centripetal force, which worked out to a spin rate of just under four-hundred kilometers an hour, (I know!) It’s on this surface that they live, work, play, and grow their food.

And what are they growing? Initially, I thought meat was right out the airlock. Raising a given value of calories of meat requires something like four to six times more resources in both vegetable matter and water than the damned plants you’re putting into the toothy end of the critter. Initially, I was sure everyone aboard was going to be vegan out of necessity.

But then I happened to visit an experimental urban farm here in Milwaukee called Sweet Water Organics. Sadly, it has since closed, but the idea was to use plants and fish in a symbiotic way. Freshwater fish were grown in tanks, the dirty water was then pumped into a hydroponic garden where their waste provided nutrients for a variety of lettuce and vegetable plants growing in racks, purifying the water that was then fed back into the fish tanks. It was a really cool setup to see in action, so I stole it and put it aboard the Ark. The fish provided animal protein for a relatively low resource cost that didn’t involve eating bugs. I kinda figured this would be good for morale.

All this defined the middle of the ship. At the front, I placed the command module and a series of labs where the crew would conduct their experiments. Crowning off the ship is a two kilometer long pleated armored cone, there to take the punishment of interstellar dust striking the bow at fifteen-thousand kilometers per second.

And that was it. I didn’t design the Ark so much as math and science did. I don’t know how close my numbers got, and I’m sure some sharp-eyed readers will find where I screwed up, but in the end, the ship was a real object in my mind. Its own unique space and world I could populate with characters, who were themselves formed and molded by it as much as anyone on Earth is influenced by their surroundings.

Can’t wait to build the next one.

Photo: Patrick S. Tomlinson
Photo credit: Jason Hillman, used with permission

Jason Hillman

Jason Hillman

Patrick S. Tomlinson is the offspring of an ex-hippie psychologist and an ex-cowboy electrician. An eclectic group of bards from Herbert to Prachett propelled him into dozens of new worlds during his formative years when he was especially vulnerable to such dubious influences.

Patrick lives in Milwaukee among a bevy of house plants in varying stages of health, where the winters offer a wonderful opportunity to disappear into his writing cave for five months at a stretch, emerging only briefly each week to watch the Packer game. Time not spent writing is split between performing stand-up comedy around the midwest, training for half-marathons, and coddling his Ford Mustang and Triumph motorcycle.