BREAKING

FUSION IN SPACE: SAN DIEGO STARTUP BETS ORBIT MAKES FUSION EASIER, NOT HARDER YC FALL 2025: ZEPHYR FUSION RAISES SEED TO BUILD MEGAWATT-CLASS IN-ORBIT REACTOR LEVITATED DIPOLE DESIGN: SINGLE SUPERCONDUCTING COIL, ZERO VACUUM WALLS NEEDED SPACE ECONOMY NEEDS POWER: MOST SATELLITES RUN ON THE ENERGY EQUIVALENT OF A TOASTER FUSION IN SPACE: SAN DIEGO STARTUP BETS ORBIT MAKES FUSION EASIER, NOT HARDER YC FALL 2025: ZEPHYR FUSION RAISES SEED TO BUILD MEGAWATT-CLASS IN-ORBIT REACTOR LEVITATED DIPOLE DESIGN: SINGLE SUPERCONDUCTING COIL, ZERO VACUUM WALLS NEEDED SPACE ECONOMY NEEDS POWER: MOST SATELLITES RUN ON THE ENERGY EQUIVALENT OF A TOASTER

San Diego, CA | Industrials / Energy

Zephyr Fusion

Powering tomorrow's industrial revolution in space.

Two plasma physicists who met operating a spherical tokamak in graduate school have a simple thesis: fusion is hard on Earth because of Earth. Remove the planet, and everything gets easier. Their company, Zephyr Fusion, is building the first megawatt-class fusion power source designed to live in orbit - where unlimited natural vacuum does the heavy lifting, and launch costs have never been lower.

YC Fall 2025 Fusion Energy Space Industrials San Diego Deep Tech

EDWARD HINSON - CEO, ZEPHYR FUSION

2025 Year Founded

1MW+ Target Power Class

35+ Years Combined Fusion Research

10x Drop in Launch Costs (Past Decade)

THE CASE

What If Space Makes Fusion Easy?

Fusion energy has been "30 years away" for roughly 70 years. The standing joke writes itself. But Zephyr Fusion's founders, Edward Hinson and Galen Burke, are not trying to fix fusion on Earth. They are trying to do it somewhere fusion makes more sense.

The core problem with fusion on the ground is containment. You are trying to heat plasma to temperatures hotter than the sun's core while stopping it from touching anything solid. On Earth, that means building enormous, expensive vacuum chambers. In space, the vacuum comes free. There are no walls. There is no friction. There is nothing at all - which is exactly the point.

Their reactor design is a levitated dipole: a single superconducting coil suspended in a magnetic field that creates a large confinement region for the plasma. Compare that to a conventional tokamak, which requires hundreds of precisely coordinated coils, and you start to understand why Zephyr thinks orbital deployment is simpler, not harder.

The timing argument is equally direct. Launch costs have fallen roughly 10x in the last decade. Mass-produced high-temperature superconductor (HTS) tapes now deliver around 10x more magnetic field per kilogram than a decade ago. Both trends converge on the same conclusion: now is the moment to attempt this.

Fusion actually gets easier in space. Unlimited vacuum means no bulky reactor walls. The environment we have been calling hostile is the environment fusion wants.

- Zephyr Fusion thesis

The Technology

Levitated dipole magnetic confinement - a single superconducting coil creates a large, stable plasma confinement region
High-temperature superconductor (HTS) magnets provide 10x more field per kg than previous generation
Natural space vacuum replaces expensive vacuum infrastructure required on Earth
Compact architecture engineered from the start for orbital deployment
Target output: megawatt-class power for large-scale in-orbit industrial use

THE PROBLEM

The Space Economy Has a Power Problem

Think about what satellites actually run on. Most of them operate on somewhere between a few hundred watts and a few kilowatts - roughly the same as a toaster, or maybe two. That is fine for communications and Earth observation. It is not fine for the next phase.

The space economy is moving from exploration to industry. In-space manufacturing, orbital fuel depots, asteroid mining, large-scale propulsion systems - all of these need power at scale. Megawatts, not kilowatts.

Solar panels are the obvious answer, except they are not. Past roughly 10 kilowatts, solar arrays become prohibitive in both mass and cost. They also stop working entirely in the outer solar system, where sunlight is faint. If you want to industrialize space seriously, you need a compact, high-output power source that does not depend on proximity to the sun.

That is precisely what Zephyr Fusion is building. A megawatt-class reactor the size of a satellite - not a power plant - that can go up on a rocket and power whatever you need, wherever you are.

Why Now?

01
Launch costs dropped ~10x in the last decade. Getting hardware to orbit is no longer the impossible barrier it once was.
02
Mass-produced HTS tapes now deliver ~10x more field per kg. Compact, powerful superconducting coils are commercially available.
03
Space's natural vacuum eliminates the most expensive part of building a fusion reactor on Earth. The environment is the infrastructure.
04
Commercial space industry is transitioning from exploration to industry at scale - and industry requires serious power.

THE FOUNDERS

Friends Since a Tokamak in Madison

CEO

Edward Hinson

Edward Hinson is a fusion physicist and engineer with over 20 years in plasma modeling and experimental reactor research. He holds a PhD in Nuclear Engineering and Engineering Physics from the University of Wisconsin-Madison, where he and Galen Burke first crossed paths operating a spherical tokamak together. He went on to postdoctoral research at the DIII-D tokamak - one of the most important fusion research facilities in the United States - and spent years at Oak Ridge National Laboratory.

Published in Nuclear Fusion, Physics of Plasmas, and Physical Review Letters.

CTO

Galen Burke

Galen Burke is a plasma physicist specializing in experimental diagnostics and fusion plasma research. He studied Engineering Physics at the University of Wisconsin-Madison, where he and Edward became both friends and collaborators during their time running a spherical tokamak together. Burke's career includes significant work at Lawrence Livermore National Laboratory - the facility behind the National Ignition Facility's historic fusion ignition milestone in 2022.

Together they bring over 35 years of combined fusion research experience to a two-person company.

They met in graduate school, built their friendship around a spherical tokamak, and spent the next 15 years accumulating the exact expertise needed to attempt this. When they finally started Zephyr Fusion, the preparation had already happened.

- From their founding story

UNDER THE HOOD

A Reactor Designed for Where It Lives

The levitated dipole concept is not new in physics circles - it was studied seriously at MIT with the Levitated Dipole Experiment (LDX). The core insight is that a magnetic dipole field - similar to Earth's own magnetic field - can stably confine hot plasma in a way that's inherently different from a tokamak's donut-shaped confinement.

What Zephyr Fusion brings to this concept is the recognition that orbital space is the perfect operating environment. The reactor's superconducting coil needs to be levitated in a vacuum. Space provides that vacuum for free, at zero additional mass or cost. Every kilogram saved on vacuum systems is a kilogram that can go toward the actual reactor.

Their design targets megawatt-class output - enough to power large-scale orbital operations. Current satellites running a few kilowatts could become orbital factories, fuel depots, or high-powered propulsion systems running hundreds of kilowatts or more.

The team is currently in R&D, simulation, and lab prototyping, with partner outreach ongoing across aerospace and defense primes, large satellite manufacturers, and constellation operators. No flight hardware has launched yet - but then, neither has any competitor's orbital fusion reactor.

2010

The Meeting

Edward Hinson and Galen Burke meet as graduate students at UW-Madison while operating a spherical tokamak together.

2010 - 2025

Building the Foundation

Hinson completes his PhD and postdoc at DIII-D and Oak Ridge. Burke works at Lawrence Livermore. Combined: 35+ years of fusion research published in leading journals.

2025

Zephyr Fusion Founded

The company is incorporated in San Diego, CA. Two physicists, one ambitious bet on orbital fusion.

Sep 2025

Y Combinator

Accepted into Y Combinator Fall 2025 batch. Raises $500K seed funding from YC.

Oct 2025

Public Launch

Launches publicly via YC with detailed technical vision. Covered by Data Center Dynamics and fusion industry media.

Nov 2025

Seed Extension

Raises additional seed funding from Pioneer Fund, Brimstone Hill Capital, Spot VC, and Syntax Ventures.

CAPITAL

Early Backers Betting on the Long Game

Round	Amount	Date	Investors
Seed	$500K	Sep 2025	Y Combinator
Seed Extension	Undisclosed	Nov 2025	Pioneer Fund, Brimstone Hill Capital, Spot VC, Syntax Ventures

Y Combinator's involvement is notable for what it signals: the world's most prominent startup accelerator is comfortable backing fusion companies, which once would have seemed implausible. The broader fusion investment landscape has shifted dramatically, with dozens of private fusion companies now funded globally. Zephyr Fusion's orbital angle gives it a distinct position in that field.

The space economy is going through the same transition Earth's economy went through during the industrial revolution. And like every industrial revolution before it, it needs a step-change in available power.

- Zephyr Fusion vision

Y Y COMBINATOR FALL 2025

YC's Fall 2025 batch included Zephyr Fusion as part of a broader wave of deep-tech and climate/energy startups. Getting into YC with a two-person fusion hardware company is itself a statement.

WORTH KNOWING

Five Things That Make This Story Different

FACT #1 🌌

Space's natural vacuum eliminates the most expensive engineering challenge in ground-based fusion. The environment most people call hostile is, for fusion, ideal.

FACT #2 🤝

Hinson and Burke have been friends and collaborators since 2010. They ran a spherical tokamak together in grad school. By the time they founded Zephyr, they had been working toward this for 15 years.

FACT #3 🔋

Most satellites today run on the energy equivalent of a toaster. Zephyr's target is megawatt-class. That is a gap of three orders of magnitude - and everything interesting in the space economy lives on the megawatt side.

FACT #4 🧲

Their levitated dipole design uses a single superconducting coil. A conventional tokamak uses hundreds. Simplicity is not a compromise here - it is the architectural advantage that makes orbital deployment practical.

FACT #5 📈

Two macro trends converged to make their timing argument: launch costs down 10x in a decade, and HTS tape performance up 10x in the same period. Zephyr Fusion was founded at the intersection of both.

THE BIGGER PICTURE 🚀

Humanity's previous industrial revolutions were all powered by step-changes in energy - coal, oil, electricity, nuclear. Zephyr Fusion's thesis is that the next one, which happens off-planet, needs the same step-change. Fusion in orbit is their answer.

FIND THEM