News Ticker

INTERVIEW: Andy Weir Talks About THE MARTIAN, Mars, Space Travel and Orbital Simulators

Andy Weir‘s debut novel The Martian (which is currently in the top 20 on several best seller lists as of this writing) tells the story of Mark Watney, the seventeenth astronaut on Mars and the first one stranded there…and possibly the first one to die there.

Andy is a software developer by trade, currently programming on the Android operating system. He initially released The Martian, which he wrote as a hobby, for free in pieces on his blog. When some of his readers requested a more readable format, he put together a kindle version for the lowest price Amazon allowed: 99 cents.

The subsequent events were those that many authors dream of: picked up by a major publisher, large advance, movie rights…lending strength to the writing advice most often given: first, write a great book. Or, in Andy’s case: first, learn about orbital dynamics, write a simulator for an ion propulsion engine, absorb everything about Mars…and then write a great book.

Andy was gracious enough to submit to my barrage of emails and questions on a wide range of topics.


LARRY KETCHERSID for SF Signal: I’ve read/heard in other interviews that you worked at Sandia Labs. But where did you get your knowledge of orbital dynamics/mechanics and of Mars? Were these degreed studies or is this a hobby/obsession?

ANDY WEIR: I’ve had an deep interest in spaceflight my whole life, and I actively go out of my way to learn what I can about it. So basically, it’s all a hobby of mine. My only actual training in anything is in computer programming (which is my day job).


Screenshot from Andy’s simulator used to map out ship movements for The Martian

LARRY: I’ve also heard that you wrote your own orbital sim program, and that you are currently working (when not writing and promoting) as an Android programmer. Please tell me you didn’t write the simulator in Java!

ANDY WEIR: Fear not, I wrote the simulator in C++.

LARRY: Does your simulator only work with the ion propulsion system for the main Hermes (the Mars ship in THE MARTIAN) or did you put in other booster types in case there were other means to rescue Watney that needed to be mapped out?

ANDY WEIR: I could vary the thrust that the ion engines produced, but the simulation didn’t do point-thrust simulations like chemical engines would do. Those don’t require simulation; you can solve those with a spreadsheet much more easily.

LARRY: THE MARTIAN could have been a much darker book. There are several points where a turn toward the dark side could have happened: several times during Watney’s fight to survive; when NASA decided they would attempt to save Watney, no matter what the costs; and others. Were you intentionally aiming for a more positive slant? Have you thought about writing a darker version?

ANDY WEIR: Yes, that was a deliberate decision on my part. It could have been the story of a man clinging to sanity as he suffers crippling stress and loneliness. I didn’t want to go that route. I wanted a light read that had a generally positive and (hopefully) inspiring theme.

My idea is to make 600 liters of water (limited by the hydrogen I can get from the hydrazine). That means I’ll need 300 liters of liquid O2.

I can create the O2 easily enough. It takes twenty hours for the MAV fuel plant to fill its 10-liter tank with CO2. The oxygenator can turn it into O2, then the atmospheric regulator will see the O2 content in the Hab is high, and pull it out of the air, storing it in the main O2 tanks. They’ll fill up, so I’ll have to transfer O2 over to the rovers’ tanks and even the space suit tanks as necessary.

But I can’t create it very quickly. At half a liter of CO2 per hour, it will take twenty-five days to make the oxygen I need. That’s longer than I’d like.

LARRY: There is a lot of tech in the book, which I personally enjoyed, and thought the “log” concept (Watney trying to document his story for science, history, etc.) lent itself to that. But some of it could be harsh for non-techies. Did you ratchet it up, or down, or change it at all when this went from a blog “book for free” to an edited book?

ANDY WEIR: I didn’t change the technical details much when editing it for print. Mostly the changes were adding exposition to the NASA scenes, making the Earthside characters more distinguishable from each other, etc. Stuff like that.

LARRY: In the Ares 3 mission team in THE MARTIAN, you have a Commander, Pilot, Doctor and three “mission specialists” (to use the NASA term). Could any of the others have coped with being stranded better than Watney?

ANDY WEIR: Excellent question. I’ve actually put some thought in to that. I think most of them would have died under the circumstances, with the exception of Johanssen. Johanssen is a software engineer and electrical engineer. She would probably know how to fix the communication system and get back in contact with NASA right away. So she would have had all of NASA to come up with ideas to keep her alive.

LARRY: Agreed, but without the botany skills, it would have been a race between how long it would take her to get comms back online versus when she started to run out of food. One of my favorite employees came to me one day and said she’d been offered her dream job and could no longer work for me. I told her I could outbid them, but she said it was working in video/images/audio for NASA. I cried and asked her to hire me in the future. In recompense, she sometimes regales me of astronaut stories (and has shown me the refrigerated vault where the original Mercury, Gemini and Apollo films were kept before they were translated to digital!). One astronaut story was of an ISS astronaut who would put signs in front of the cameras (which the world could see eventually, via the Freedom of Information Act, as you use in your book) some that would say “Please make up room.” Astronauts are smart asses. So is your Mark Watney. What research did you do for his character? Who did you speak with?

ANDY WEIR: I didn’t do any research at all on astronaut personalities. I had no contacts at NASA or JPL before the book came out. I made his personality up for the story.

At the time, I figured it was unrealistic. I assumed real astronauts were much more serious and professional. But after the book came out, I got emails from NASA personnel and actual astronauts saying the personalities of Mark and the other Ares 3 astronauts were very plausible. So I guess I stumbled in to that one with luck.

Mars, The New Space Race

LARRY: The type of hobbyist passion for space one has to have to make a simulator to make sure orbital dynamics are correct seems to be making a resurgence.  That passion and enthusiasm may head toward the levels it hit during the space race days (which I enjoyed experiencing while my Dad was chasing Apollo rocket stages in the South Atlantic working for RCA) which spawned many industries and general interest from citizens. Then most of the world and most Americans went into a lull, with only events/accidents similar to what you portray in your book (Apollo 13, the Space Shuttle tragedies) re-kindling any interest. Now with SpaceX, Planetary Resources and other companies in the news, and with other countries pushing themselves into space, interest seems to be flaring up again. THE MARTIAN and books like it could be nice fuel for this, since your book is ‘near-future’, describing technology that is mostly in-hand and could be used. As an enthusiast, what levers and buttons do you think need to be pushed to get Americans and the world excited about the need for space travel, and a Mars landing in particular?

ANDY WEIR: I’m not sure how to get Americans excited over the prospect. The truth of the matter is that there is no profit motive for going in to space, so it’s hard to justify spending the tens of billions a manned mission to Mars would cost. Though there is one thing we Americans have a history of valuing over money, and that’s national pride.

The Chinese are working on their space program and have a manned Moon landing planned for the 2020s or 2030s. If they see that through, you may see Americans start to demand a better space program.

LARRY: Why NASA? Why not portray one of the private space firms? I did enjoy the non-American participation in the book (and will say no more to avoid spoilers) but did you ever consider having this be a Mars landing from another country’s space program?

ANDY WEIR: The story takes place in the near future. While we are in a lull with our manned space program, the US is still far and away the preeminent technology leader in space technology. I just don’t see anyone catching up in the short time between now and when The Martian takes place.

A likely scenario, however, is an international effort. However, this would complicate the story. Readers already understand the concept of NASA and Mission Control as they were during the Apollo days. If I had made the Ares program an international thing, I would have had to make up a bunch of ancillary changes. Like Mission Control being somewhere other than Houston, and other organizations than NASA being involved in the decision-making processes. I didn’t want to get mired up in explaining all that to the reader, and also didn’t want to lose the realism that Houston and JPL carry as they are today.

LARRY: Some of the conceptual plans for Mars missions include one-way missions (like Mars One). There is a psychological difference between committing to never coming back and Watney’s realization that he may never get back. Watney is always upbeat. What psychological effects — including those of long space travel, time on a planet and Watney’s own stranded psyche — did you think through as you were writing?

ANDY WEIR:  I made a conscious decision to keep the novel from getting too dark. I wanted a lighthearted adventure. I didn’t want to portray the crushing loneliness and constant despair that a normal person would suffer in that situation.

LARRY: Which of the several current Mars programs are you following, and which do you believe has the biggest chance to be successful? THE MARTIAN features a planned two-way missions; what are you thoughts about the viability of the current one-way missions?

ANDY WEIR: The next NASA probe will be similar to Curiosity. I have high hopes and expectations of that. I don’t believe one-way missions are plausible unless they are setting up a large infrastructure. As in: hundreds, perhaps thousands of people. That’s well outside our technology right now.

LARRY: There is a large discrepancy in the cost of certain space missions, with NASA’s being the most expensive, SpaceX and others being a second tier (though they do vie for NASA contracts), and the recent extremely low budget launch from India (4.5 billion rupee [$73 million] mission to Mars price tag according to this article). With the India launch, there was resistance due to the dollars spent versus using that money to fight the poverty that plagues most of India. In THE MARTIAN, there is a huge additional expense once NASA determines Watney is still alive. What thinking when through that part of the plot? Did you ever consider having the question of the value of one astronaut’s life be a major point?

ANDY WEIR:  In the context of the story, that money wasn’t just being spent on keeping Watney alive, it was effectively buying more astronaut-on-mars time. Ares 3 was supposed to last 31 sols, and Mark ended up being on Mars for 549. That’s about 18 times the original duration. So imagine if, back in the 1970s, NASA could have spent a few hundred million dollars to make Apollo 17 last 51 days instead of its planned 3.

LARRY: Competition and the investments (private and government) seem to be speeding up the tech. The next SpaceX launch looks to be carrying a test Laser communications project which certainly would have been handy for Watney.

ANDY WEIR: It certainly would have. I’m a huge fan of SpaceX and I root for them in everything they do. I’m very much looking forward to their Falcon Heavy test launch. It can put 53,000kg in to LEO for an estimated 100 million dollars. Compare that to NASA’s SLS which is slated to put 143,000kg in to LEO for 40 BILLION dollars. There’s no reason for SLS at all if SpaceX can make Falcon Heavy work.

LARRY: And I’m ready to see those SpaceX Falcon Space Legs in action. There is a certain international cooperation in your story. Have you any thoughts on the Ukraine situation and its possible effect on being able to utilize Russian resources to send American astronauts to the ISS?

ANDY WEIR: The situation in Ukraine is very serious, but I don’t think it will interfere with US/Russian cooperation on ISS. That’s covered by a treaty we have and I don’t think either nation is willing to violate it.

LARRY: A plethora of books about Mars and Mars colonization are out there. your Google presentation you mention that you read a lot of classic sci-fi. What books have you read that have influenced your content and writing style?

ANDY WEIR: The main inspiration for The Martian was the real-life events of Apollo-13. I would say my favorite man-vs-nature sci-fi story is Tunnel in the Sky (Heinlein).

LARRY: Andy, one last question: The only other writing I’ve found for you is a short story called “The Egg“. What are you writing plans? What are you working on next?

ANDY WEIR:  I have a writing page with lots of other shorts stories and a few serial novels. Currently I’m working on a pitch for my next book. I’m keeping the details to myself for now. I want the publisher to hear the pitch from me first. :)

About Larry Ketchersid (45 Articles)
Author of two novels (Dusk Before the Dawn, Software by the Kilo) and one volume of non-fiction stories. CEO of a security software and services company; co-owner of JoSara MeDia, publisher of iPad apps, print and eBooks. Runner, traveler, Sharks fan, Rockets fan, Packers shareholder.