Andy Weir
Author of The Martian and Project Hail Mary
Where to hear and read about Andy Weir1 episode or test
Andy Weir is the author of The Martian, Artemis and Project Hail Mary, a plot-driven science fiction writer who began as a programmer posting free work online. The thing most worth learning from him is to chain every event to the one before it and to plant clues backward, so surprises feel earned and readers trust accurate science enough to enjoy long explanations.
readers will forgive any amount of exposition if you make them laugh about once a paragraph.
Project Hail Mary Author Reveals His Writing Process (Andy Weir Interview)
Andy Weir: the story and the lessons
1How Andy Weir built an audience and sold The Martian
Weir spent ten years building a small free readership before The Martian. He posted free short stories and web comics on his site until he had about 3,000 regular readers, roughly one new reader a day.
He had been laid off from AOL in time to cash in stock options, which gave him three years of runway. His first novel found no agent or publisher. He says he is no marketing guru and his only advice is to make a lot of content over time.
He wrote The Martian in public and let fans check the math. He posted a chapter every six to eight weeks and warned readers the chapters were not canon and might be revised.
He wrote it in Boston, where he knew no one and had nothing to do after work. His nerdy fans double-checked his math, and their feedback kept him going.
A 99-cent Kindle listing sent the book up Amazon's lists without promotion. Fans asked for an e-reader file and then for Kindle delivery, so he used Kindle Direct Publishing at the 99-cent minimum. Fans who had already read it free bought it anyway, all at once.
He had refused donations, so buying the book was their way to pay him. He calls it "almost astroturfing but not intentional."
An agent, Random House and Fox all arrived within about a week. At hundreds of copies a day, agent David Fugate offered to represent him, and Random House and Fox came within four days.
The film option was about $25,000 for 18 months against a $200,000 purchase price, so it was no sign the film would be made. He only believed it once the first day of shooting was done and every contract activated. The first printed proof, with his picture on the back, felt most real.
Weir prefers a traditional publisher because he only wants to write. He calls a book a product and the publisher a marketing and publicity machine with over a century of experience. It pitches Barnes & Noble, Waterstones, Target and Walmart, places ads, and sends advance copies to outlets like the New York Times Book Review.
He names Hugh Howey as the true self-publishing success, since Howey can do everything himself. His advice to an unknown writer is to query literary agents first, then e-publish, and expect many rejections.
2How Weir turns a science daydream into a novel
Weir keeps asking what if until each credibility problem has an answer. A mad scientist inventing mass-conversion fuel strained belief, and a found alien ship stole the spotlight. A self-replicating fuel sounded like life, which led to a space microbe, Astrophage, and then to humanity's survival being at stake.
His own reasoning: "if you give it energy, it makes more of itself. That sounds like life."
He glued several unfinished story ideas together and sanded off the seams. Project Hail Mary combined a mass-conversion fuel, a first contact story he had always wanted to write, and an abandoned story about a woman with godlike authority over governments.
The abandoned story supplied the character Stratt. He suggests checking old drafts for parts that fit a new project.
Weir picks the stakes to fit the story and keeps them small when he can. Project Hail Mary is his first book with all of humanity at stake. In The Martian one man's life was at risk, and in Artemis Jazz risked deportation.
He is tired of science fiction feeling it must have global stakes, since romance, action and drama don't need planetary ones.
He outlines four or five turning points and improvises the path between them. He always knows the next plot point he must reach, but not what will get him there. In Project Hail Mary the reveals were set in advance: the spacecraft, the Tau Ceti system, the Astrophage flashbacks, then Rocky's ship and first contact.
After first contact he had to invent how the two of them learn to communicate.
Weir builds an alien world by chaining physical constraints. He started from data for a planet near 40 Eridani: about eight Earth masses, roughly 2 g, a 46-day orbit. Liquid water at about 200 °C needs about 29 atmospheres, which needs a strong magnetic field, and little sunlight reaches the surface, so the biosphere works like an ocean.
He designed Rocky to fit that world. The planet was later shown to be a mathematical error, and he says "let's get past that."
He tracks the numbers in spreadsheets so the science stays consistent. Project Hail Mary had the most of any of his books, covering relativistic rocket equations and fuel-to-mass ratios, how much energy Astrophage absorbs, and how much food energy the Eridians need.
3Weir's rules for plotting
Weir makes every plot event the direct result of the one before. He describes The Martian as "one long cascade failure," where each fix creates the next problem. The plot never leans on luck.
He dislikes stories where things are suddenly struck by lightning, because readers then have to suspend disbelief for a lucky break.
He plants clues in early chapters after deciding what must happen later. When The Martian got too easy, he chose something to break. The breakdown came about 80,000 words in, and he went back and showed that part acting up in earlier chapters.
Writing out of order lets him set up what he only decided later, so the surprise feels fair in retrospect.
Weir wants heroes who outsmart the reader with a fair, proactive plan. He cites Breaking Bad, where Walter White is about to be killed by Gus Fring and offers to deliver Jesse Pinkman. Walter lures Jesse into killing Gus's cook, which makes Walter the only man who can make the drugs.
Weir expected an outside rescue and was wrong, and loved it: "In retrospect, I had all the information to work that out, but I didn't."
He takes well-worn premises and does them his own way. Stranded on a planet is Robinson Crusoe and first contact is everywhere. He adds scientific accuracy and aliens with no shared language or face, and one who cannot stand in Earth's air, so a barrier separates the two.
He only noticed this habit three books in.
Weir admires setting a few clear rules and testing what they cause. He praises Asimov for handing readers the three laws of robotics and then tweaking one. In the Speedy story, a robot's self-preservation is weighted equal to obedience, so it circles a radioactive crystal until a first law threat breaks the loop.
Fixed rules generate plots on their own.
He learned plot by consuming huge amounts of stories, not by studying structure. Books and movies gave him an unintended grasp of structure. He then builds in what he loves as a reader, such as chain reactions and clever surprises.
4How Weir keeps readers trusting and entertained
Weir gets the science right so readers stop checking it. After a chapter or two, readers assume the science is correct, and reviewers say they skimmed the physics but trusted it. The microwave door mesh line, about 80 pages in, ties the story to everyday reality, and readers tell him they never knew it.
The line: "Anything smaller than the wavelength is functionally non-existent to that photon."
He replaces ten pages of showing with one paragraph of plain exposition. He has a love-hate relationship with show, don't tell, and says his science is too deep to dramatize. If one paragraph saves ten pages, he takes it.
He uses a first-person narrator so pausing to explain feels natural. It only feels odd if you ask who the narrator is talking to. Accept that someone is telling you the story and the aside fits.
"You can get away with that a lot easier in first person than you can in third."
He works in a joke whenever an explanation runs long. Humor stops exposition from reading like a Wikipedia article. He is a naturally smartass person, so jokes mostly come on their own, and he adds one when a stretch goes without a zinger.
Friends who read his books say they can hear his voice.
Weir aims only to entertain and uses no symbolism. Astrophage is not an allegory for climate change or a metaphor for Ryland's inner turmoil. He treats science fiction as a setting, like saying Chicago, that can hold romance, noir or drama.
He wants readers to enjoy the book and tell him it is awesome, which he calls "that sweet external validation."
5How Weir builds characters, and where he overshot
Weir calls characters his weakest craft because he is plot-driven. He sometimes wishes characters could be machinery that is part of the story, and says even generous reviewers would say he has work to do here.
Basing leads on himself worked two opposite ways. Mark Watney is an idealized Andy, with good traits magnified and flaws removed. Jazz in Artemis is the real Andy at her age: immature, lazy, unethical, always seeking shortcuts.
He overshot with Jazz. She caused all her own problems, and readers found it hard to root for her.
Weir gave Ryland Grace one core fear and put him in its opposite. Grace is pathologically afraid of conflict. His paper was challenged, so he left academia and taught middle school, where no one pushed back. The story then makes him the lynchpin of humanity's survival.
Weir planned a trope inversion: instead of a fearful man finding courage and joining the crew, Grace is forced to go. He changes only when he must choose between Rocky and himself.
He gave Grace a quirk that stays a mystery until the story explains it. Grace never swears and says fudge and what the heck instead. Readers wonder why until they learn he is a teacher.
After the film was greenlit, Ryan Gosling emailed him: "Let's make this fudging movie."
Rocky is built from physics first, then given a grumpy personality. His limited English and habit of repeating a word three times make him endearing. He and Grace bicker like an old couple, yet would die for each other.
In a cut exchange, Grace says Rocky must wait for epoxy to harden, and Rocky says it is very important to finish soon. Grace answers "I'll wait faster."
6Weir on flashbacks and amnesia in Project Hail Mary
Weir advises writers against amnesia and used it anyway. He calls it a cheesy trope, but it puts the reader on the same footing as the hero, so no backstory has to be dumped up front.
He also says flashbacks annoy him in fiction, yet the whole book leans on them.
He wrote each flashback to change something in the present. Each is a memory triggered by what Grace is doing at that moment, and each answers one question and raises another. Told in order, Strat and others would vanish after act one and Rocky would not appear until past halfway.
His rule: "make sure that the plot was always advancing and things were changing."
He avoids flashbacks that only deliver backstory. He says they are often used to make you do your homework: a character is mid-action, then the story jumps three weeks back to show him being nagged by his wife.
7Weir's heroes and his view of AI writing
Weir names Asimov, Heinlein and Clarke as his holy trinity. Asimov changed one rule and followed it, Heinlein asked what happens once travel between planets exists, and Clarke stayed scientific and realistic, such as aliens who don't care about us.
He recommends Asimov's The Caves of Steel as the first book to read, since it is a true novel and the characters return in several more books.
His favorite astronaut is John Young, for staying calm. Young commanded Apollo 16 and walked on the moon. Astronauts' heart rates usually climb into the 140s at launch, while Young's never got above 70.
Weir sums up his attitude as "I'm on a rocket."
Weir expects AI to out-write humans someday but not yet. He compares denial to cab drivers insisting self-driving cars won't happen. He expects human-written stories to become an artisanal craft, with authors who know both storytelling and the AI steering it.
Today he finds it too weak to brainstorm with. A friend's AI-written superhero story gave detail on minor things and repeated information, which he calls an "AI accent."
Project Hail Mary Author Reveals His Writing Process (Andy Weir Interview)
Andy Weir explains how he turns a daydream about interesting science into a plot-driven novel, and how he keeps readers trusting him through accurate science, humor and clean cause and effect. The technique worth hearing is his habit of going back into earlier chapters to plant the clues that make later surprises feel earned.
Weir spent ten years building a small free readership before The Martian. He posted free short stories and web comics on his site until he had about 3,000 regular readers, roughly one new reader a day.
He had been laid off from AOL in time to cash in stock options, which gave him three years of runway. His first novel found no agent or publisher. He says he is no marketing guru and his only advice is to make a lot of content over time.
He wrote The Martian in public and let fans check the math. He posted a chapter every six to eight weeks and warned readers the chapters were not canon and might be revised.
He wrote it in Boston, where he knew no one and had nothing to do after work. His nerdy fans double-checked his math, and their feedback kept him going.
A 99-cent Kindle listing sent the book up Amazon's lists without promotion. Fans asked for an e-reader file and then for Kindle delivery, so he used Kindle Direct Publishing at the 99-cent minimum. Fans who had already read it free bought it anyway, all at once.
He had refused donations, so buying the book was their way to pay him. He calls it "almost astroturfing but not intentional."
An agent, Random House and Fox all arrived within about a week. At hundreds of copies a day, agent David Fugate offered to represent him, and Random House and Fox came within four days.
The film option was about $25,000 for 18 months against a $200,000 purchase price, so it was no sign the film would be made. He only believed it once the first day of shooting was done and every contract activated. The first printed proof, with his picture on the back, felt most real.
Weir prefers a traditional publisher because he only wants to write. He calls a book a product and the publisher a marketing and publicity machine with over a century of experience. It pitches Barnes & Noble, Waterstones, Target and Walmart, places ads, and sends advance copies to outlets like the New York Times Book Review.
He names Hugh Howey as the true self-publishing success, since Howey can do everything himself. His advice to an unknown writer is to query literary agents first, then e-publish, and expect many rejections.
Weir keeps asking what if until each credibility problem has an answer. A mad scientist inventing mass-conversion fuel strained belief, and a found alien ship stole the spotlight. A self-replicating fuel sounded like life, which led to a space microbe, Astrophage, and then to humanity's survival being at stake.
His own reasoning: "if you give it energy, it makes more of itself. That sounds like life."
He glued several unfinished story ideas together and sanded off the seams. Project Hail Mary combined a mass-conversion fuel, a first contact story he had always wanted to write, and an abandoned story about a woman with godlike authority over governments.
The abandoned story supplied the character Stratt. He suggests checking old drafts for parts that fit a new project.
Weir picks the stakes to fit the story and keeps them small when he can. Project Hail Mary is his first book with all of humanity at stake. In The Martian one man's life was at risk, and in Artemis Jazz risked deportation.
He is tired of science fiction feeling it must have global stakes, since romance, action and drama don't need planetary ones.
He outlines four or five turning points and improvises the path between them. He always knows the next plot point he must reach, but not what will get him there. In Project Hail Mary the reveals were set in advance: the spacecraft, the Tau Ceti system, the Astrophage flashbacks, then Rocky's ship and first contact.
After first contact he had to invent how the two of them learn to communicate.
Weir builds an alien world by chaining physical constraints. He started from data for a planet near 40 Eridani: about eight Earth masses, roughly 2 g, a 46-day orbit. Liquid water at about 200 °C needs about 29 atmospheres, which needs a strong magnetic field, and little sunlight reaches the surface, so the biosphere works like an ocean.
He designed Rocky to fit that world. The planet was later shown to be a mathematical error, and he says "let's get past that."
He tracks the numbers in spreadsheets so the science stays consistent. Project Hail Mary had the most of any of his books, covering relativistic rocket equations and fuel-to-mass ratios, how much energy Astrophage absorbs, and how much food energy the Eridians need.
Weir makes every plot event the direct result of the one before. He describes The Martian as "one long cascade failure," where each fix creates the next problem. The plot never leans on luck.
He dislikes stories where things are suddenly struck by lightning, because readers then have to suspend disbelief for a lucky break.
He plants clues in early chapters after deciding what must happen later. When The Martian got too easy, he chose something to break. The breakdown came about 80,000 words in, and he went back and showed that part acting up in earlier chapters.
Writing out of order lets him set up what he only decided later, so the surprise feels fair in retrospect.
Weir wants heroes who outsmart the reader with a fair, proactive plan. He cites Breaking Bad, where Walter White is about to be killed by Gus Fring and offers to deliver Jesse Pinkman. Walter lures Jesse into killing Gus's cook, which makes Walter the only man who can make the drugs.
Weir expected an outside rescue and was wrong, and loved it: "In retrospect, I had all the information to work that out, but I didn't."
He takes well-worn premises and does them his own way. Stranded on a planet is Robinson Crusoe and first contact is everywhere. He adds scientific accuracy and aliens with no shared language or face, and one who cannot stand in Earth's air, so a barrier separates the two.
He only noticed this habit three books in.
Weir admires setting a few clear rules and testing what they cause. He praises Asimov for handing readers the three laws of robotics and then tweaking one. In the Speedy story, a robot's self-preservation is weighted equal to obedience, so it circles a radioactive crystal until a first law threat breaks the loop.
Fixed rules generate plots on their own.
He learned plot by consuming huge amounts of stories, not by studying structure. Books and movies gave him an unintended grasp of structure. He then builds in what he loves as a reader, such as chain reactions and clever surprises.
Weir gets the science right so readers stop checking it. After a chapter or two, readers assume the science is correct, and reviewers say they skimmed the physics but trusted it. The microwave door mesh line, about 80 pages in, ties the story to everyday reality, and readers tell him they never knew it.
The line: "Anything smaller than the wavelength is functionally non-existent to that photon."
He replaces ten pages of showing with one paragraph of plain exposition. He has a love-hate relationship with show, don't tell, and says his science is too deep to dramatize. If one paragraph saves ten pages, he takes it.
He uses a first-person narrator so pausing to explain feels natural. It only feels odd if you ask who the narrator is talking to. Accept that someone is telling you the story and the aside fits.
"You can get away with that a lot easier in first person than you can in third."
He works in a joke whenever an explanation runs long. Humor stops exposition from reading like a Wikipedia article. He is a naturally smartass person, so jokes mostly come on their own, and he adds one when a stretch goes without a zinger.
Friends who read his books say they can hear his voice.
Weir aims only to entertain and uses no symbolism. Astrophage is not an allegory for climate change or a metaphor for Ryland's inner turmoil. He treats science fiction as a setting, like saying Chicago, that can hold romance, noir or drama.
He wants readers to enjoy the book and tell him it is awesome, which he calls "that sweet external validation."
Weir calls characters his weakest craft because he is plot-driven. He sometimes wishes characters could be machinery that is part of the story, and says even generous reviewers would say he has work to do here.
Basing leads on himself worked two opposite ways. Mark Watney is an idealized Andy, with good traits magnified and flaws removed. Jazz in Artemis is the real Andy at her age: immature, lazy, unethical, always seeking shortcuts.
He overshot with Jazz. She caused all her own problems, and readers found it hard to root for her.
Weir gave Ryland Grace one core fear and put him in its opposite. Grace is pathologically afraid of conflict. His paper was challenged, so he left academia and taught middle school, where no one pushed back. The story then makes him the lynchpin of humanity's survival.
Weir planned a trope inversion: instead of a fearful man finding courage and joining the crew, Grace is forced to go. He changes only when he must choose between Rocky and himself.
He gave Grace a quirk that stays a mystery until the story explains it. Grace never swears and says fudge and what the heck instead. Readers wonder why until they learn he is a teacher.
After the film was greenlit, Ryan Gosling emailed him: "Let's make this fudging movie."
Rocky is built from physics first, then given a grumpy personality. His limited English and habit of repeating a word three times make him endearing. He and Grace bicker like an old couple, yet would die for each other.
In a cut exchange, Grace says Rocky must wait for epoxy to harden, and Rocky says it is very important to finish soon. Grace answers "I'll wait faster."
Weir advises writers against amnesia and used it anyway. He calls it a cheesy trope, but it puts the reader on the same footing as the hero, so no backstory has to be dumped up front.
He also says flashbacks annoy him in fiction, yet the whole book leans on them.
He wrote each flashback to change something in the present. Each is a memory triggered by what Grace is doing at that moment, and each answers one question and raises another. Told in order, Strat and others would vanish after act one and Rocky would not appear until past halfway.
His rule: "make sure that the plot was always advancing and things were changing."
He avoids flashbacks that only deliver backstory. He says they are often used to make you do your homework: a character is mid-action, then the story jumps three weeks back to show him being nagged by his wife.
Weir names Asimov, Heinlein and Clarke as his holy trinity. Asimov changed one rule and followed it, Heinlein asked what happens once travel between planets exists, and Clarke stayed scientific and realistic, such as aliens who don't care about us.
He recommends Asimov's The Caves of Steel as the first book to read, since it is a true novel and the characters return in several more books.
His favorite astronaut is John Young, for staying calm. Young commanded Apollo 16 and walked on the moon. Astronauts' heart rates usually climb into the 140s at launch, while Young's never got above 70.
Weir sums up his attitude as "I'm on a rocket."
Weir expects AI to out-write humans someday but not yet. He compares denial to cab drivers insisting self-driving cars won't happen. He expects human-written stories to become an artisanal craft, with authors who know both storytelling and the AI steering it.
Today he finds it too weak to brainstorm with. A friend's AI-written superhero story gave detail on minor things and repeated information, which he calls an "AI accent."