Natalya Bailey’s tiny engines could change the economics of space exploration, much as the jet engine altered commercial air travel

There’s a sweet spot about 22,000 miles above the planet. Only in this narrow band of space can an object achieve geosynchronous orbit, moving at the same speed as Earth’s rotation and staying fixed above one point on the surface. It’s beachfront real estate in the void.
This part of space came of age with the baby boomers in the 1960s. It’s been dominated by the few governments, aerospace giants, and telecoms with enough money and expertise to build a complex SUV-size object and lob it almost a tenth of the way to the moon. Everything in this stratum is highly planned and expensive; a satellite here can cost more than $300 million to produce.
Far below, at an elevation of about 370 miles, is the cheaper and riskier near-Earth orbit that has matured in step with millennials. It’s a free-floating, unruly mess populated by a new generation of miniature satellites that can be as small as toys and made for as little as $10,000. Already, they’re being stuffed aboard launch rockets like Tic Tacs.
The falling cost of building space tech and putting it into orbit has entrepreneurs, researchers, and oil- tankertracking hedge fund analysts lining up to claim their corner of the upper atmosphere. About one-third of the 4,600 man-made objects in Earth orbit went up in the past decade, including a record 553 last year, according to the United Nations.
All of this activity poses a problem: There’s no efficient way to position these objects once they’ve been launched. The result is something like thousands of boats adrift at sea. Until now, there was little reason for engineers to streamline satellite propulsion, because geosynchronous satellites were large enough that they could devote a few extra pounds to bulky, chemical-driven engines. Smaller space objects in near-Earth orbit mostly just float along without propulsion, descending eventually, as NASA requires, into a so-called graveyard orbit, where they will burn up within 25 years. A tiny satellite or lab that could scoot itself around would be able to go higher, into less-dense layers of space, then steer into a fiery atmospheric death once obsolete. It would also be nimble enough to dodge the 18,000 or so pieces of manmade junk zipping around the globe like a hypersonic trash dump.
The frantic new space race needs an engine. Preferably a tiny one.
Inside an old brick candy factory north of Boston, 30 young rocket scientists with scruff fringing their hairnets shuffle among machines and curl over microscopes, tinkering with tiny tools like watch makers. Accion Systems Inc. essentially makes one product, a device about the size of a deck of cards that’s designed to slowly and silently nudge satellites, spacecraft, and other galactic ephemera through the blackness. Technically, the Tile—an acronym for tiled ionic liquid electrospray—is an ion engine, which is to say it runs on a stream of charged particles, much like a battery. Stick enough of them onto a giant craft, and you can putter out to Mars.
At least, that’s Natalya Bailey’s hope. Her company’s little engines haven’t yet left the ground. The 31-year-old chief executive officer travels in a tight orbit around Accion’s office. She spends most of her time amid a scrum of desks, occasionally swinging by the lab to see how the Tile is faring against a phalanx of machines that squeeze and shuffle it to approximate the violence of a rocket launch and the vacuity of space. The only significant time she spends in her private office is to pump milk for her 9-month-old daughter, who goes to the day care next door. “The world needs this technology,” Bailey says of her engine. “And it isn’t very clear that someone else can do it better.”
The cost of launches is shrinking as quickly as the cost of satellites, with a rash of startups developing rockets for lighter, unmanned payloads. Some are producing designs using 3D printers or filing patents for space catapults. One company, Vector Launch Inc., plans to build a fleet of simple rockets and sling them by the hundreds from a mobile launch pad. Vector CEO Jim Cantrell says that in the not-too-distant future, two or three launches will take place around the world every day. He estimates they’ll cost $1.5 million to $3.5 million apiece, far below the already groundbreaking $60 million that SpaceX charges for a resupply run to the International Space Station. “It consumerizes space,” says Cantrell, a SpaceX alumnus. “I’ve got neighbors that can write a $1 million check.”
At that price, doing business in orbit becomes much more tempting for a wide range of industries. The gold rush is on, and Accion is poised to become a premier shovel supplier. “They’re pretty core to what the future is,” Cantrell says.

The Tile is a rectangular piece of silicon and plastic whose smallest incarnation measures about 3 inches wide. It’s built in layers, cakelike, with an electric plate atop a tank of liquid-salt propellant atop a membrane with hundreds of holes. When the engine fires, propellant particles jet away from the charged plate, stream through the holes, and shoot out into space like subatomic pingpong balls. Whatever the Tile is attached to—be it shoebox-size satellite, robot, or astronaut—is gently and silently pushed in the other direction. “It’s a mix of plasma physics [and] fluid dynamics,” Bailey says. The effect is subtle: “When some are operating efficiently, you visually can’t even see that they’re on.”
The beauty of the Tile is in what it lacks. It contains no pressurized tanks, no bulky valves, no chemicals that could cause a costly launch accident. It’s also tireless. Right now, a Tile can run for about 42 days straight. Bailey is shooting for 417 days—10,000 hours—though Accion won’t know how quickly it can reach that goal until after its first engines leave the planet. “That would get us the entire Earth-centric space market,” she says.
Much of today’s cosmic clamor is coming from busy billionaires, the Musks and Bezoses who bring competition to NASA and its cozy network of defense contractors, then retire for the evening to nibble roast iguana and wage Twitter wars. Even less- moneyed rocketry upstarts hew to a certain machismo: When Cantrell isn’t building rockets, he’s racing Porsches. Bailey refers to this group as “the billionaire cowboys,” and she’s most decidedly not among them. For one thing, she looks like Audrey Hepburn, with a preppy sense of style. She’s also an introvert and a quiet, calculating problem solver.
For as long as she can remember, she’s puzzled over what’s out there. As a kid drifting offto sleep on a trampoline outside her family’s home near Portland, Ore., she would track the International Space Station. She remembers cobbling together a preteen version of the Drake Equation on those nights and realizing that the likelihood of intelligent alien life was something greater than zero. Star Trek marathons with her father catalyzed her cosmic thinking, as did her mother’s unexpected death when Bailey was 8. The house lost some of its order—some of its gravity—which led to more nights gazing skyward on the trampoline.
In college, Bailey got a hard-won paid internship at now-merged aerospace giant Hamilton Sundstrand and joined a team repairing turbine engines. She hated it. “It was the opposite of pushing the envelope,” she says. “Nothing new ever went into that building. Nothing new ever left that building.”
By the time she set off to get a master’s degree in mechanical engineering at Duke University, the idea of logging 30 years at a place like Boeing Co. or NASA had lost all appeal. She tried her hand at finance and later law, and was unlucky enough to excel at both. “I made it pretty far down that path, but then I thought, Wait, if I become a lawyer, then I’m a lawyer and that’s what I do,” she recalls. “What if I don’t want to do that on Tuesdays?”
Eventually, Bailey’s Duke adviser bought her a plane ticket to Boston so she could start a doctorate at the Massachusetts Institute of Technology. The LSAT was old news; she was going to rocket-engine school.
One theory for why NASA and its corporate partners haven’t perfected an ion engine is that the space behemoths are too big to try. Their missions are so grand and expensive that risk is squeezed out, along with much of the drive for innovation. “It’s the opposite of a virtuous cycle,” says Rob Coneybeer, a venture capitalist and early Accion investor who cut his teeth in the 1990s at Martin Marietta. “It’s a negative spiral.”
But there’s another reason satellite propulsion has been slow to evolve: It’s boring. Some of the best and brightest minds in rocket science are in it for the bang. They like a big burn, the high stakes of a 10-story tower quivering with liquid hydrogen and a computationally complex 18,000-miles-per-hour flight.
At MIT, Bailey worked with Paulo Lozano, a professor of aerospace engineering who started looking into the potential of ion engines about two decades ago. He found he had trouble getting funding. At one of his conference presentations, three people showed up. “It’s hard to convince people that this is something interesting,” he says. “It was even hard for me to convince academia that this is something to look at.” Bailey was attracted to it because it was subtle and largely overlooked by the space establishment.
When she arrived, Lozano’s team was working through two major technical problems: The charged metal would corrode quickly, causing the whole thing to short-circuit in a small explosion. Bailey and Louis Perna, a fellow student who eventually co-founded Accion with her, took the research in a new direction by replacing the metal with a charged liquid, insulating the process and making it ultra-efficient and far less volatile.
As Bailey was preparing to defend her doctoral thesis, she was also raising funds for Accion. (The name is a reference to a summoning charm in the Harry Potter books.) “Somewhere in there we decided I was making more of the decisions and going to more of the meetings,” she says of her relationship with Perna. “So when it came time to form the C-corp, we put my name down.” Accion wants to change the economics of space exploration in much the same way the jet engine altered commercial air travel.
Sometime in the next few weeks, a Rocket Lab launch vehicle will thunder skyward from a tiny peninsula on the heel of New Zealand. Its payload will include a shoebox-size space lab built by students at a California high school, which will feature the first of four Accion units heading to space in the next year or so.
Although its first customers make small satellites, Accion is building its business plan around midsize machinery, which tends to be owned by corporations and countries with more money than high school students have. The company has already secured $7 million in contracts from the U.S. Department of Defense, in addition to $10.5 million in venture capital. Accion is cagey about prices, but it touts its products as 10 to 100 times cheaper than existing options. One virtue of the Tile is that, simply by adding a few more engines, you can move a larger object or go farther and faster. That could be useful for machines doing detailed weather research, defense surveillance, or communications.
“My personal hope and ambition is that they become the in-space propulsion company,” Coneybeer says. He and Accion’s other investors are most excited about the Tile’s potential to scale, Silicon Valley’s magic word. The market is expanding quickly, and Accion can theoretically serve everyone. Bailey’s team has already prepared a straightforward manufacturing plan, not unlike a smartphone factory workflow, with the heart of the machinery baked into a tiny chip. Assuming Accion gets the Tile right, the process will be easy to replicate.
Bailey is thinking even bigger than near-Earth orbit. Someday, she wants to sell explorers and scientists a one-way trip to Mars, even to other solar systems—a level of ambition she shares with the billionaire cowboys. She’s also thinking about her own trajectory: What, if anything, comes after Accion? In her free time, she’s been taking flying lessons, strapping into a small plane with her baby. “It’s kind of like our family car,” she says. A pilot’s license is one of the only remaining qualifications that would buttress her application to become an astronaut. NASA has already rejected her twice.
“I don’t know why,” she says. “I’m a pretty good specimen. I even have great vision.”