Andy Weir, author of The Martian and Project Hail Mary, discusses his writing process, the craft of science fiction, and his path from self-published serial to bestselling novelist and film adaptations.
How Andy turns ideas into books
Ideas begin as daydreams about interesting science; for Project Hail Mary the kernel was a mass-conversion fuel that could turn matter into light for propulsion.
He iterates through implausible setups (mad scientist, alien ship) until the concept becomes a self-replicating life form — a microbe that grows on stars and spores outward using mass conversion.
The existential threat emerges: the microbe infects the Sun, forcing a desperate mission to the one unaffected star (Tau Ceti) using the same fuel.
Hail Mary is a pastiche of abandoned story ideas glued together: a first-contact story, the mass-conversion fuel, and a character (Stratt) with godlike authority to solve a crisis.
Stakes as propulsion
Stakes drive the story; Hail Mary uses extinction-level stakes (billions dead, humanity at risk) with a tiny, desperate crew.
Weir prefers lower, personal stakes (The Martian: one life; Artemis: one woman’s well-being) and finds it odd that sci-fi often defaults to planetary stakes when other genres don’t.
High stakes made Hail Mary easier because they emerged naturally from the premise, but he intentionally avoids them as a crutch.
From premise to draft
He identifies four or five major turning points, then writes toward them, improvising the connective tissue.
Example turning points in Hail Mary: waking with amnesia → realizing he’s on a spacecraft → realizing he’s in the Tau Ceti system → flashbacks revealing Astrophage and Stratt → Rocky’s arrival and first contact → communication established.
Amnesia is a “cheesy trope” he advises against, but it lets the reader discover the world alongside the protagonist, avoiding exposition dumps.
Why you should avoid flashbacks (and when they work)
Flashbacks annoy him when they’re homework: pausing the present for irrelevant backstory (e.g., a nagging wife three weeks earlier).
His flashbacks advance the plot and unfold mysteries in real time; each memory is triggered by the current action and raises/answers questions.
He used them reluctantly to interweave the Earth-side backstory (Stratt, mission prep) with the present-day ship story, otherwise Rocky wouldn’t appear until halfway through.
How to make readers trust your story
Trust comes from not breaking immersion; scientific accuracy builds a “credit” with readers — after a chapter or two they assume the science is right and skip the math.
Early exposition (e.g., microwave mesh explaining wavelength interaction) tethers the fiction to reality and teaches something true.
He treats “show, don’t tell” with an asterisk: direct exposition saves pages, and first-person conversational narration makes it feel like a person talking to you, not a textbook.
Humor is the lubricant: readers forgive any exposition if you make them laugh once a paragraph.
Give your character one fear
Weir considers character depth a weakness; he’s plot-driven. Mark Watney was an idealized version of himself; Jazz Bashara was a flawed, younger version — too flawed, making her hard to root for.
For Ryland Grace he built a character from whole cloth: core trait = pathological fear of conflict and confrontation (left academia after a paper was challenged, became a middle-school teacher where kids think he’s cool and no one pushes back).
Quirks follow from the core: never swears, uses “fudge,” “gosh” — later explained by his teacher persona.
The scenario forces him to confront his fear: he’s non-confrontational, doesn’t want to die, said no to the mission, was forced onto it.
Real character change comes only at the climax: choosing to save Rocky (and Rocky’s species) over returning to Earth, believing it’s a suicide sacrifice.
How he wrote Rocky
Started with zero constraints: alien need not survive Earth conditions. Used real (later retracted) exoplanet data for 40 Eridani: ~8 Earth masses, ~2g surface gravity, 46-day orbit → 200°C surface temp.
To keep liquid water at 200°C: ~29 atm pressure. To retain atmosphere against stellar wind: extremely strong magnetic field.
Thick atmosphere blocks sunlight → biosphere becomes an atmospheric “ocean” with photosynthetic layers and apex predators on the ground.
Designed speculative biology from there: spider-like, rock-eating, ammonia-breathing, sound-based communication.
Rocky’s personality: likable “golden retriever” energy, but actually grumpy and insulting in a bickering-couple dynamic (e.g., “wait faster” while epoxy cures). Linguistic quirks (tripling words for emphasis) make him lovable.
You should plant clues for your reader
He avoids deus ex machina by seeding future problems early: if something breaks at 80k words, he goes back and plants hints (e.g., “acting up a bit”) so the failure feels earned.
Uses spreadsheets extensively: relativistic rocket equations, Astrophage energy absorption/enrichment rates, Eridian biology/caloric needs — all to keep the physics internally consistent.
Why Andy avoids symbolism
No ulterior motive, no moral, no symbolism of any kind. Astrophage is not an allegory for climate change or inner turmoil.
He writes “straight up here’s a sequence of events,” almost journaling real events. Goal: entertainment.
He enjoys taking well-trodden SF territory (stranded on a planet, first contact) and doing it his way: rigorous science, truly alien aliens, no common language, physical barriers between species.
How The Martian became a bestseller
Software engineer with three years’ runway wrote The Martian while lonely in Boston; serialized a chapter every 6–8 weeks on a bare-bones HTML site to ~3,000 readers built over 10 years of short fiction.
Readers (nerds) fact-checked the math, improving accuracy. Refused donations; suggested cancer research instead.
Fans demanded e-reader format → self-published via KDP at $0.99 minimum (Amazon’s floor). Evangelical fan base bought it en masse → algorithmic boost → top-selling SF ebook.
Literary agent David Fugate approached → Random House print deal and Fox film option same week. Option = $25k for 18-month exclusive right to buy rights later; studios option everything.
Physical proof copy was the “this is real” moment; film became real only after first day of filming (contracts activate).
Do you need a publisher?
Prefers traditional publishing: publishers are a marketing/publicity machine no individual can match (distribution to B&N, Waterstones, Target, Walmart; ads in reader publications; NYT review copies; interview coordination).
Advice for unknown authors: query agents first; if rejected, e-publish. Build an audience with free short stories/webcomics over time. He’s not a marketing guru.
Two rules for a great plot
Causal chain: every event knocks into the next (cascade failure). No coincidences or lightning strikes. The Martian is one long causal sequence.
Protagonist outsmarts the reader: the solution makes perfect sense in retrospect, all seeds were there, but the reader didn’t see it. Example: Walter White in Breaking Bad offering Jesse to Gus to save himself — proactive, logical, surprising.
Is sci-fi really a genre?
Sci-fi is a setting, not a genre (like “Chicago,” not “action”). You can have SF romance, SF noir, SF drama.
Asimov: three laws of robotics as a rule set, then explores edge cases; mixed genres (SF noir in Caves of Steel).
Clarke: extreme hard SF, physics never cheated (Rendezvous with Rama: rotating cylinder, centrifugal gravity, aliens indifferent to humans).
Heinlein: wild speculation within physics (interplanetary travel, pirates, social structures).
Joy of SF = joy of discovery: vicarious high when a character figures out something no one else knows.
Will AI write better than humans?
Inevitable that AI will eventually write better stories. Bleak but honest; hard to convince someone when livelihood depends on disbelief.
Future: AI reads all books + reviews → generates book predicted to get good reviews → tailored fiction per user (local AI knows your history, writes a book only you love).
Tension: shared cultural touchstones (Harry Potter, Hail Mary) vs. hyper-personalized content. Likely both coexist; human writing becomes artisanal (like painted portraits vs. photos).
Automation historically creates more jobs (pilots: automation → more planes/flights → more pilots). Writers become AI operators/guides.
Current AI has an “AI accent”: wrong detail density, repetition, rudimentary. Not useful for brainstorming yet. Reinforcement learning will close gaps.
Andy’s heroes and recommendations
Astronaut John Young: Apollo 16 commander, heart rate never above 70 on launch — stoic, unflappable, spanned Mercury through Shuttle, walked on Moon.
