Andy Weir on his strange journey from self-publishing to Hollywood

Andy Weir has a deep fear of flying. He has not set foot on an airplane since 2007, when he traveled from his home turf in Northern California to visit his mother in Phoenix.

So in 2013, when he found himself signing lucrative contracts for the publishing and film rights to his debut novel, The Martian, he did everything over the phone. He never once met any of the disembodied voices calling from New York and L.A., never shook anyone’s hand or clinked champagne flutes in a cushy conference room. “I was honestly worried it was a scam,” Weir says. “Out of nowhere someone offers to make all my dreams and lifelong ambitions come true and pay me a big pile of money? It seemed too good.”

The situation was improbable. Just one year prior, Weir, a computer programmer by trade, had given up hope of becoming a professional writer after failing to get a single agent or publisher excited about his work. But then he posted The Martian online, and it generated such buzz that now here he was, signing mid-six-figure deals with both Crown Publishing and Twentieth Century Fox. His self-publishing success story—well-paid tech nerd becomes really well paid novelist—made him the envy of every would-be author who ever fantasized about ditching his day job. Even critics were on board. (“Brilliant. A celebration of human ingenuity and the purest example of real sci-fi for many years,” said The Wall Street Journal.)

Such a dizzying reversal of fortune just didn’t make sense to Weir. So it had to be a hoax, right? “But then the checks started coming in,” he says with a laugh. “And I thought, ‘Well, if it’s a scam, then they’re not very good at it.’ ”

The Martian debuted on the New York Times best-seller list at No. 12 this past March. Since then, the book (now in paperback) has sold 180,000 copies, and Ridley Scott is directing the adaptation, which stars Matt Damon as Mark Watney, an astronaut left behind on Mars after his crew mistakenly concludes he died during the mission. (Jessica Chastain, Kristen Wiig, and Chiwetel Ejiofor are among his A-list castmates.) Stranded in space, Watney has no way to communicate with Earth, nor enough food to sustain him until help can arrive.

It’s a riveting adventure saga (think Cast Away meets Apollo 13) with enough physics and math to satisfy hardcore sci-fi fans. But it’s Watney’s witty voice—the book begins with “I’m pretty much f- - -ed”—that helped The Martian cross over into a mainstream hit. He’s a lovable character who’s part Han Solo, part MacGyver…and one big part Andy Weir. “My theory is that every protagonist is someone the author wants to be or who the author wants to screw,” says Weir, 42. “Just so we’re clear, Mark Watney is who I want to be. He has all the qualities I like about myself magnified without any of the qualities I dislike.” He smiles. “Mark Watney isn’t afraid to fly.”

Weir lives in a modest two-story house in Mountain View, Calif., home to Google and other tech giants. A life-size decal of Buzz Aldrin on the moon greets you in the front hallway, as do the author’s two doted-upon cats, JoJo and Demi. In the living room, there’s a bookshelf devoted to board games—Weir’s current favorite is Tzolk’in: The Mayan Calendar—and a makeshift bar with top-shelf liquor for the cocktails-and-games parties he throws.

Though Weir is not used to interviews and worries about being dull, he’s a gracious host, eager to show his visitor the computer program he created while writing The Martian that maps the orbital trajectories of Earth and Mars. He meticulously researched every aspect—from the chemistry to the number of daily calories Watney would need to stay alive—and says he’s earned praise from NASA engineers for his efforts. “If people don’t like the book and say it’s because of the main character, well, that’s a matter of opinion,” he says. “But what bugs me is when people say there are scientific inaccuracies when there are not.”

As if to illustrate his point, moments later his phone rings. It’s screenwriter Drew Goddard (World War Z), who’s polishing his script for The Martian and has a technical question about the temperature of Watney’s shelter. Without missing a beat, Weir explains how a heater would eat up battery power on Mars.

Talking to Weir, you can practically hear that scary-smart brain of his clicking and whirring. He quit his job at the software company MobileIron in April to write full-time, but he still looks more computer programmer than hotshot author: His striped button-down shirt is a little rumpled, and his bright blue eyes hide behind decidedly non-hipster, wire-rim eyeglasses. He’s currently single—and is characteristically self-effacing about that. “I don’t even date; I’m terrible with women,” he says.

Weir was raised in the Bay Area, the only child of a particle-physicist father and an electrical-engineer mother who divorced when he was 8. He played around with Apples and PCs as a kid and later studied computer science at UC San Diego until he ran out of money before he could finish. He’d always aspired to be a writer, but he didn’t want to bet on it. “I’m essentially a risk-averse person,” he says. “I wasn’t willing to take a chance on a lifestyle where I could fail and be economically ruined. Computer programming is pretty much guaranteed income. I’m good at it and I like it. But

it was my second choice.” In his late 20s, after getting laid off from AOL and cashing in some of its then-pricey stock, he gave himself three years to get published. He wrote a book, Theft of Pride—”It’s a space-opera thing”—but couldn’t find an agent. (An even earlier attempt, The Observer, has thankfully been lost in the mists of the pre-Internet era, he says.)

In 2002, with his self-imposed time limit up, Weir returned to programming. But he never stopped writing. He put sci-fi Web comics and short stories on his website, Galactanet, and slowly acquired a loyal readership. In late 2009, he started posting The Martian chapter by chapter. “It was a serial,” he says. “I never thought it would be more than that.” Readers loved it, though, and soon they were asking if he would make it available for the Kindle. Weir obliged, using Amazon’s self-publishing arm and setting the price at the minimum of 99 cents. By early 2013, The Martian had become a top sci-fi title, selling 35,000 copies in four months.

That’s when it came to the attention of producer Simon Kinberg (X-Men: Days of Future Past). “I fell in love with it,” he says. “The concept is good, but there’s a million sci-fi books about people being marooned on other planets. It’s the way The Martian is executed—the reality of the science and the humor and humanity of Mark Watney.” The publishing and film-rights deals were worked out in March 2013. “It was…an eventful week,” Weir says. He remembers walking away from his desk at MobileIron to take calls in the conference room. “It was like, ‘Oh, I need to figure out this program bug and also I need to go negotiate my movie deal,'” he says with a laugh. “The day it all came together I had to take off from work. I was so stressed out I couldn’t breathe.”

Weir may have obsessed over every detail of the book, but he seems pretty laid-back about the big-screen version, which begins production this month in Hungary. He’s delighted that Damon is playing Watney and that Scott—who knows a little something about films set in outer space—is directing. And as a fan of NBC’s Community, he is super geeked out that Donald Glover is on board as well.

For now, Weir has no plans to visit the set—though the idea of seeing his book reimagined with living, breathing people is enticing enough that he could maybe imagine reversing his no-fly policy. “If they invite me to go…I’d have to really think about that,” he says. “I think I could be a great mission-control guy in the background with no lines.” Copy that.

This article appears in Entertainment Weekly‘s Nov. 7 issue.