The Invitation: Why We Must Leave Earth

Chapter 1: The Invitation

The email sat in Maya Chen's inbox like an unexploded firework—fourteen words that shouldn't have been there, glowing against the morning she had planned to spend milking cows.

Congratulations. You have been selected as a finalist for the Aurelia Space Design Challenge.

Below that line, a second sentence, even more impossible: Please report to the Aurelia Institute, Pasadena, California, on September 14. Travel arrangements have been made.

Maya read it once, twice, three times. The fog drifting off the pastures behind her family's small dairy farm in Ridgway, Colorado, had not turned pink yet. The rooster across the road had not yet announced itself. It was 5:47 a.m., and her alarm had not even gone off, because Maya had woken up the way she always woke up on weekends: instantly, completely, as if her brain had never accepted the concept of slow transitions.

She had reached for her phone out of habit, half-asleep, expecting the usual scroll of climate-news alerts, college forum spats, and her best friend Priya's late-night memes. Instead, she had found this email, sitting in a sender line she had never seen before: admissions@aurelia-institute.org. The subject line read simply: Aurelia Space Design Challenge — Result of Phase One.

Maya sat up in bed. Her room was a layered archaeology of her obsessions. Above the desk where she did her online schoolwork hung a printed poster of the Apollo 11 crew, four men in puffy white suits standing next to a ladder that reached nowhere. Above the bed hung a stitched cloth map of the Solar System, every planet hand-sewn in cloth of slightly wrong scale, with Mars in a fabric so red it seemed almost to glow. On the wall across from the door, taped with painter's tape that was slowly losing its will to live, was her own creation: a poster that read WHY SPACE? in cut-out letters from an old issue of *Astronomy* magazine, surrounded by a swirling cloud of hand-drawn arrows pointing to facts she had collected over three years of obsessive reading.

*We evolved on the plains of Africa and conquered every continent. We will not stop at one planet.*

*Earth has been hit before. Earth will be hit again.*

*There are 8 billion of us and one of our planet. The math doesn't work forever.*

*Curiosity is not a luxury. It is a survival trait.*

She had written those lines for herself, mostly, so that she could glance up from physics homework and remember *why*. Why bother learning orbital mechanics from an old textbook she had bought at an estate sale? Why spend her Saturday nights building model rockets from PVC pipe and printer ink? Why read three books on Martian geology when most of her classmates were already arguing about what to put on their college applications?

Because someone had to think about it. Because someone had to be ready.

And now, apparently, someone was going to give her a chance to actually try.

The email didn't say what she had submitted. It didn't have to. Maya knew exactly what she had submitted, because she remembered the night she had sent it: a 47-page PDF called "Bootstrapping a Closed-Loop Colony on Mars Using Local Resources and a Distributed Fabrication Network", with diagrams she had drawn by hand and equations she had checked and re-checked with the grim focus of a kid who had nothing to lose and everything to prove. She had submitted it to the Aurelia Space Design Challenge because the form had been in front of her, because the prize was "an internship at the Aurelia Institute's Martian Surface Systems Lab," and because—well, because no one from Ridgway, Colorado, population roughly 1,000, had ever, to her knowledge, applied to anything like it.

She had submitted it the way a kid who had once jumped off the barn roof because she thought she could fly submits things. With no expectation that the universe would reply.

The universe had replied.

Maya set the phone down on the pillow beside her and looked out the window. Below the ridge, the valley was still dark. Above the dark, the stars were just beginning to thin against the coming blue. Somewhere up there, *in real time*, a company was flying a helicopter on Mars. Somewhere up there, a probe was photographing the icy moons of Jupiter for signs of life. Somewhere up there, the small, persistent, fragile project of human beings reaching past the edge of their cradle was continuing, as it had continued, in one form or another, for the entire two hundred thousand years of her species' existence.

Now, it appeared, the project might include her.

The Inheritance

She did not tell her parents first. She told her grandfather.

José Chen—"Abuelo" to Maya, "Pops" to anyone else who could pronounce the word—was in his workshop behind the main house, a low-roofed shed with a corrugated tin door that he had bought used and painted the color of a stop sign. He was sitting in a wheelchair now; the neuropathy in his legs had been getting worse for six years, and lately he had taken to saying, with the kind of gruff humor that masked enormous tenderness, that he had "retired from standing." Maya suspected that was not entirely true. She had seen him pull himself up onto the wood lathe just last month to tighten a belt. But he liked the chair because it gave him permission to stay in the workshop without pretending to be busy.

He had once worked at NASA's Jet Propulsion Laboratory. He had not built rockets, exactly—he had built the things that built the rockets, the precision ground fixtures that held spacecraft components during assembly, the test stands that shook them until they gave up their secrets, the beryllium-alloy jigs that held mirrors steady while they were polished to tolerances measured in fractions of a wavelength of light. He had worked on the Mars Pathfinder mission in 1997, and the Mars Exploration Rovers in 2003, and the Curiosity rover in 2011, and he had walked away with a small bronze pin for each one and a stack of binders so heavy they required a handcart to move.

He had retired to Ridgway the year Maya was born, because his son—Maya's father—had taken over the farm, and because Ridgway was the kind of place where a man who had spent four decades working in clean rooms could finally breathe air that wasn't filtered. He grew tomatoes. He started a small but stubborn orchard. He built, in his workshop, a series of increasingly elaborate clocks, each one weirder and more beautiful than the last, ticking away the hours of a quieter life.

And he talked to Maya. About everything. About the way the Surveyor 1 spacecraft had soft-landed on the Moon by firing its rocket engine in the dark, and trusting the radar altimeter, and trusting the engineers who had built the radar altimeter, and trusting the engineers who had trusted the previous engineers, all the way down a chain of human fallibility that ended, somehow, in a footpad resting gently on lunar dust. About the moment, in 1997, when the Pathfinder team had gotten a clear signal from Sojourner for the first time and a guy named Matt Golombek had walked out of the control room and cried in the parking lot. About the time his team had found a one-millimeter scratch on a critical component, the night before integration, and had spent nineteen hours rebuilding it from scratch, and nobody had ever heard about it because nobody ever hears about the disasters that don't happen.

Maya understood, sometimes, that her grandfather had spent his career making sure that the universe did not notice the things she had been spared from worrying about. He had been the scaffolding. The quiet thing in the background. The handshake between human ambition and physical reality.

He had also, she realized now, been preparing her.

Maya pushed open the tin door. The workshop smelled of pine resin, machine oil, and the faint metallic tang of beryllium dust, which she knew was probably a health hazard and tried not to think about. Her grandfather