Ariel Ekblaw on Self-Assembling Habitats and Why the Real Space Cities Will Float

Ariel Ekblaw grew up with two former Air Force pilots. Her father flew the A-10; her mother completed fighter-pilot training and qualification in an era when women were still barred from combat. That household, she tells Lex Fridman, kept talking about courage, exploration, and what it means to stand at the vanguard of something hard. A long American pipeline from fighter pilots to astronauts loomed over her childhood even though her parents never flew in space.

Her father was also a science-fiction fan, and he handed her Heinlein and Asimov. The Foundation trilogy stuck because it was less about gadgets than about how you structure a society across vast distances and timescales. Her current favorite is Neal Stephenson's *Seveneves*, which inspired her PhD and later NASA work on swarm robotics for spacecraft. Stephenson, she notes, also had a hand in Blue Origin, a reminder that hard science fiction can leak into actual engineering.

That loop between authors and builders now sits next to another influence: the Long Now Foundation's question of what this inflection point requires if humanity is to have a long horizon. Talk of millions of people living and working in space, in the vein of Jeff Bezos, demands architecture bigger than any rocket payload fairing. Self-assembly and other in-space construction methods are her answer to that constraint. Coming from a military family they used to say luck favors the prepared, and they even kept a family pandemic plan they never expected to use.

Existential risks still matter in her circle at MIT, but what she finds more compelling lately is using space technology to keep Earth livable rather than rehearsing a Hollywood escape. Satellites that map climate and, more speculatively, space-based geoengineering are examples of that pivot. The harshness of vacuum is also a forcing function: habitats that scrub CO2, cool efficiently, and survive radiation have spin-offs for wildfire-era houses that suddenly need to be nearly airtight. Figure out food in space, Fridman suggests, and you may figure out how to eat better on the ground.

When Ekblaw says swarm, she means intelligent structures and crawling robots mixed together, not HAL with a mind of its own. Future habitats would sense their own life-support state and work in symbiosis with small robots on the outside. Those robots, in the spirit of *Seveneves*, would crawl the hull looking for micrometeorite punctures, leaks, and other faults. Diagnosis comes first; later she wants them to repair in place, like ants living in a tree.

Fully distributed systems scare people, she admits, but they are also powerful because they are redundant in a harsh environment. Instead of one monolithic station, you might shut a blast door and move crew into another node, or fly Stephenson-style arklets that dock into temporary stations and then separate. Tesserae, her PhD project, takes that idea into hardware: tiles packed flat in a rocket, released in microgravity, and drawn together by electropermanent magnets on their edges. There is no human in the loop, and no central agent saying tile one should go to tile two.

The demo hides the hard part, which is error. Proximity sensors and magnetometers let a tile tell a good bond from a bad one, then pulse off and try again. Anyone in self-assembly, she says, will tell you that error detection and correction matter the way they do in DNA sequences or protein folding. "They know if they're in a toxic relationship and they need to get out."

Lab tiles were about three inches wide; a couple of years earlier they flew to the ISS to test code, the state machine, and the algorithm. The team is now building the first human-scale tiles, 2.5 feet on an edge. The dream structure is a buckyball about ten meters across, a spherical volume grander than any current ISS module. The point of next-generation space architecture, she argues, is not merely survival: when you float in, you should get goosebumps the way you do walking into stunning architecture on Earth.

Asked to imagine gigantic future structures, Ekblaw offers three candidates. The first is a space cathedral, secular if you like, built around long sight lines. On Earth you stand on the floor and look up; in orbit you could float at a central node and see spires run off in every cardinal direction. The second is more organic: not a Tesserae shell but living nodes that dock together.

Those nodes would be plesiohedrons, space-filling solids. Cubes are the simple case; a truncated octahedron is a leading candidate because it can pack without gaps and meet at airlocks on every side. Stack enough of them and you can grow any macro shape, including a nautilus Fibonacci spiral. One node might be sleeping quarters, another a greenhouse, another a depot.

Stations today, once built, are basically done. Modular self-assembly lets you disassemble and reconfigure when the mission, the headcount, or even a space conference changes. Window tiles could become a berthing port so five new ships can dock. Daniela Rus's Pebbles work at CSAIL, with interchangeable magnetic units of programmable matter, is part of the intellectual stack she is scaling up for large orbital structures.

The third monument is a ringworld, "just because every science fiction book ever that's worth anything has a ringworld in it." A huge torus could encircle a planet, asteroid, or small moon, offering surface area for solar panels and docking. A figure in her thesis shows a hexagonal tiling of a torus generated in Mathematica. They chose the buckyball first because it is the most efficient surface-area-to-volume shape, and surface area is what you pay to ship; the torus study asks whether the same Tesserae tiles could build other geometries.

Ekblaw has flown nine times on the vomit comet, the parabolic aircraft that pitches up at forty-five degrees so passengers get a burst of free fall. Early Tesserae tests used passive tiles with no electronics, just magnet polarity, to see whether assembly was energetically favorable. There is no true zero gravity, she stresses: Newton's law says every pair of masses attracts, and zero-g is public shorthand for microgravity, which is weightlessness in free fall.

The feeling is profound and unlike anything on Earth. A pool is the closest analogue, but water drags you; in the cabin a finger tap against the wall sends you across the fuselage at full speed. Instructors tell you to make a memory on the plane, because the experience is so foreign that a few days later you have already forgotten exactly how it felt. The cost of each parabola is a 2g pullout that can strain a neck if you move too fast, but she would not call it a profound biological insult.

Orbit is different. You get the overview effect, the blue marble, which she hopes to see one day, and if you stay long enough your bones, muscles, and even the shape of your eyeballs change. An afternoon on the vomit comet does not do that. Keeping humans thriving in microgravity, she says, is still an open scientific problem for deep-duration missions.

A round trip to Mars is about three years, not because the cruise itself lasts that long but because the planets only line up now and then. One way is six to nine months, then a wait on the surface until the orbits align again, then six to nine months home. That duration, she tells Fridman, is a different problem class from a few days to the Moon. If a crew or a machine breaks, three days is recoverable and three years is not.

The classic big problem is radiation. The ISS still sits inside part of Earth's magnetosphere; leave the Van Allen region and long-term health effects become serious. The supposedly small problem, which is not small, is mental health: how to keep people happy, balanced, and cooperating as crews scale. Food today is mostly freeze-dried, with occasional stunts such as DoubleTree cookies baked with Hilton. Maggie Koblenz, a staff researcher in Ekblaw's lab, is pushing fermentation, beer, wine, kimchi, miso, for flavor, shelf life, and the microbiome, and they are trying to get NASA more open-minded about it.

Water, stealing a line from former NASA administrator Charlie Bolden, is circular: this morning's fresh water is yesterday's coffee. You drink it, it goes through the body and the recycler, and you drink it again. Nearby, water ice on the Moon, and water on Mars, is a reason to build lunar infrastructure. Once you are out of Earth's gravity well, you can make propellant or drinking water without shipping it up every time.

Ekblaw once worked on SHERLOC, the astrobiology instrument on Mars that hunts, in cautious official language, for signs of past habitability rather than a headline of life. Organics and water that could have allowed life to flourish are the actual target. She thinks this lifetime may bring a better answer, if not on Mars then on an icy world such as Europa. The prospect of even microbial alien life excites her more than it scares her, though science fiction supplies reasons for humility.

Astrobiology's hard problem is that life may not be carbon-based, and detectors know how to look for DNA or RNA. How would you even build a detector for silicon-based life? She points to Sarah Walker's obsession with defining life at all, and to measures such as assembly steps, membranes, and whether reproduction is required. Fridman floats the shadow biosphere: something like alien life might already be on Earth, unnoticed because we are obsessed with our own biochemistry.

As a former physicist she hopes civilizations are prolific. If they are, the Fermi paradox follows: where are they, and is there a great filter that kills societies through war, famine, or something we have not named? "I don't think we've come up with most of them yet," she says of the ways civilizations can destroy themselves. Nuclear war is part physics and part how societies create and resolve conflict, which loops back to the human problem on a Mars ship: keep flawed people from murdering each other, not only from dying of radiation.

Culture in orbit does not have to be Earth's artifacts shipped upstairs. The Telematron, designed by Sands Fish and Nicole Boulier on her team, is a steampunk geometric percussion instrument that only really works in microgravity. Inertial sensors detect whether it is floating; two people toss it in a kind of dance, and the team later sonifies the data. On Earth it does not sound the same.

Ball sports have to be relearned. On Earth you throw on a Keplerian arc; in space you push along line of sight. After a couple of parabolas you get facility; astronauts say several days to a week on station and the brain flips. Scott Kelly's year-in-space book, and NASA's twin study with his brother, document bone-density loss, muscle atrophy, and eyesight changes as the eyeball reshapes. Between one year and a three-year Mars trip, nutrition and radiation shielding become central: lead works and is heavy, a pill is speculative, and cancer at a younger age is the blunt outcome.

Past the three-year mark, and certainly by a decade, she wants artificial gravity. Spin a habitat, or at least a treadmill section, and centripetal force gives you near-1g for part of the day, like a Gravitron carnival ride. The science is known; the engineering still needs work. That problem is one reason her MIT lab is spinning out Aurelia Institute, named for an Old English word for chrysalis: humanity at the next stage of metamorphosis into a spacefaring species.

Sex, conception, pregnancy, and raising children in space are central if you want generations rather than deployments. A few mammal studies exist; major questions remain about how a fetus develops in microgravity. Mice born in that environment had trouble walking, which fits the idea that early-childhood physics intuition crystallizes on Earth. Her near-term answer is a 1g environment for that phase of development, and MIT's Beyond the Cradle event runs a yearly workshop on pregnancy and parenthood in space because none of it is solved.

Humans stepping on Mars excites her, and she credits visionaries such as Elon Musk with building the road. She is much less excited by the idea that Mars is a near-term replacement for Earth. Perchlorates in the soil poison crops; the atmosphere is too thin to breathe and too thin to protect. Small outposts on the McMurdo model look feasible in the 2030s, maybe with first missions at the end of this decade.

Living an entire life there is the real dividing line. If the electronics break, there is no RadioShack and no supply chain for the technological complexity daily life assumes, so you drop back toward pioneer simplicity. She thinks large gatherings of humans will grow in microgravity floating cities, not on planetary surfaces. You cannot get a trillion-dollar sci-fi megastructure in one appropriation, but self-assembly lets you grow in fits and starts, the way nature does.

Children born off Earth, looking back at the original home, is an image she finds inspiring and also culturally explosive. Lower gravity could mean taller, ganglier bodies that cannot function well on Earth's 1g, a pattern science fiction such as *The Expanse* already explores with Belters. Different cultures would form; human history also shows how quickly people invent an other.

Coming from a military family, Ekblaw is worried that conflict will follow humanity into space. For decades the scientific community hung onto the 1967 Outer Space Treaty's line that space is the province of all humankind and for peaceful uses only. Rising geopolitical tension makes her fear hot wars off Earth. Tying nations together with more collaboration is the countermeasure she wants.

The ISS is her example: on the order of eighteen countries are party to the relevant arrangements, and even through the Soviet collapse and tense years with Russia, the station stayed a place the United States and Russia could work. She wants other platforms where hegemonic and developing nations intertwine success so a bad actor hurts multiple parties. The interview took place as war had broken out in Ukraine; she had not been sleeping much, with family, friends, and colleagues in both countries, many of them crying, many of them refugees.

She believes basic human compassion and love are things technology can catalyze, and that giant space projects are one way great powers escape purely military scripts. Fridman adds that watching commercial rockets during the pandemic was an understated source of hope amid loneliness and politics. Ekblaw agrees that the domain should stay collaboration, not war.

In-space manufacturing is the other construction path besides shipping tiles. Microgravity is excellent for extrusion: a long beam that would sag on Earth can become a truss in orbit, and miniature tests were slated to fly to the ISS in a few months. MIT was also returning to the Moon, with her organization leading a mission as early as late 2022 or early 2023 to the south pole, the same historic neighborhood planned for Artemis III. The hope was that payload data would support that human landing.

On that lander rides a nesting-doll stack: a SpaceX rocket, a lander, a rover, and on top of the rover a single astro ant, a tech demo rather than a true swarm. The crawling robots have four magnetic wheels and can stick to any magnetic surface; mobility was already tested on materials in microgravity on the vomit comet. They can run decentralized or talk to a central base station. She cites Bill Anders of Apollo 8: they came all the way to the Moon and what they really discovered was Earth. To bring more of humanity along, the team was exploring something like Twitch Plays Pokémon with the robot, or at least fully open data.

NASA is already thinking hard about human-robot interaction and levels of control. Gateway, the planned lunar-orbit station, is meant to run for months with no humans because operations may be seasonal, a test of autonomous maintenance and debris-dodging navigation. Kate Darling's work on attachment to robots matters more in space, where a social robot can be a teammate against loneliness. In 2017, on one of their first zero-g flights, they flew a Media Lab social robot for a tiny human study. Habitats must be homes: you cannot open a window and blow off steam, so biophilia or even a VR headset has to be designed in.

NASA still has not decided whether married couples or single crew members are better. Civilian missions such as Inspiration4 and the then-upcoming Ax-1 flight may reveal ordinary human dynamics better than hand-picked astronauts. The pandemic was a rough analog, and recovery time is why Mars is so much harder than the Moon: three days versus three years. Projects in her catalog include Valentina Sumini's inflatable robotic tail, the AgriFuge plant spinner astronauts must tend by hand, and AstroAccess flights that treat some Earth disabilities as orbital hyper-abilities.

Commercial space has thrilled her because it empowered the MIT program. Instead of waiting five years for a grant, she fundraises like a startup founder and buys ISS access through SpaceX or NanoRacks, or suborbital time on Blue Origin. Axiom, Orbital Reef, Starlab, Oasis: in a few years she expects to rent a module of lab space in orbit. Prices have dropped enough that Aurelia is spinning out in part to democratize zero-g flights beyond MIT, including courses for students worldwide. NASA is not being displaced, she argues; it grew the commercial low-Earth-orbit ecosystem so it can push to Mars and Europa instead of spending its budget forever maintaining a station.

Getting Starship-class access right is brutally hard, and she thinks SpaceX's iterative, public failures are a feature NASA cannot easily copy with taxpayer dollars. Trailblazers at SpaceX, Blue Origin, Firefly, NASA, and ESA are building the road; the remaining job is public education, Apollo-style, that the Moon return and commercial stations are already happening. She wants more raw, messy research on social media rather than overproduced press conferences, and a real-life Starfleet Academy so people who were told they had to be math-and-science types can still enter. "We need space lawyers. We need space artists."

The most beautiful idea in space, for the former physicist, is the symmetry between particle physics and astrophysics waiting to be tied together. A liberal-arts mix of physics, mathematics, and philosophy taught her the human condition, which she thinks habitat designers skip if they stay purely in engineering. Two summers at CERN hunting supersymmetry left her professors sadder as parameter space closed; she stood in line overnight on July 4, 2012, for the Higgs announcement, having never queued for a Harry Potter premiere. The Higgs did not immediately become technology, she says, but it is still critical knowledge, and new physics that enabled worse weapons would have to be answered with human compassion.

Her hottest take, the one she thinks people disagree with, is life in floating cities rather than on planetary surfaces. Low Earth orbit might look like neighborhoods of shiny objects, which is a regulatory headache for astronomers. Beyond Earth, growth would be amoeba-like pockets around the Moon, asteroids, Mars, and Lagrange points such as JWST's L2, not a uniform shell. Property rights on the Moon are the gnarly question: companies need to know they can mine and sell, but who grants the right? That is why she doubled down on space lawyers, and why the book *Into the Anthropocosmos* names the commons problem of how we will treat space the way we have treated Earth's climate.

Her advice to young people is that this is the first time in human history we sit at the cusp of an interplanetary civilization, and she does not think we will lapse back. You no longer have to be shoehorned into one career: artists who want to make space art, or to communicate a feeling about space, are needed as much as scientists and engineers. Her own path from physics to aerospace was possible because she found teammates. Fifty graduate students, staff, and faculty sit behind the person on the podcast, including her co-founder and CEO, who sat with her during the taping.

The lone-wolf genius myth in academia has not been her life. Shing Lu, the arts curator on the initiative, pushed her on the first ISS mission to run an international open call for art instead of only engineering payloads. It turned out to be the first such open call for art to the station. Consciousness, she says simply, is that we are aware of our own thoughts and meta-aware enough to discuss that awareness on a podcast. Expanding circles of awareness, from an Earth species to a solar-system species, is a gift for a curious mind.

Asked for the meaning of life, she answers first as a human soul, not a scientist: family, her biological reproducing unit. Then a second purpose arrives, doing good things for humanity, being both a local person and a global one, maybe someday a Star Trek-style citizen of something larger. Those layers can coexist. Fridman leaves her with Seneca: there is no easy way from the earth to the stars.