Zephyr Fusion

YC F25 · Active · Powering tomorrow's industrial revolution in space

Competitors

Companies closest to Zephyr Fusion
Company	Category	Status	Program
Helion EnergyShared: fusion power, fusion energy, buildingActiveOther	Other	Active	YCS14
Maritime FusionShared: fusion energy, reactor, powerActiveOther	Other	Active	YCW25
QuindarShared: satellites, aerospace, industryActiveOther	Other	Active	YCS22
ExosatShared: satellites, aerospace, orbitActiveAI	AI	Active	YCS26
RadicalShared: satellites, aerospace, orbitActiveOther	Other	Active	YCW23

Adjacent

Companies next to Zephyr Fusion
Company	Category	Status	Program
ElodinShared: satellites, aerospace, tomorrowActiveOther	Other	Active	YCW24
AlbedoShared: satellites, aerospace, orbitActiveOther	Other	Active	YCW21
WardstoneShared: satellites, aerospace, fractionActiveOther	Other	Active	YCF25
Apollo Atomics, Inc.Shared: reactor, energyActiveOther	Other	Active	YCX26
IonworksShared: large scale, space, costActiveOther	Other	Active	YCS24

Also from F25

All of F25

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AirCapsThe AI copilot for in-person conversations.ActiveAI	AI	Active
AlderAI employees for finance, starting with accounts receivable.ActiveAI	AI	Active
Aleph LabAI language buddy in the games kids loveActiveAI	AI	Active

About Zephyr Fusion

Zephyr Fusion is building the first in-orbit fusion power source: a megawatt-class reactor enabling large-scale industry in space, at a fraction of the cost of equivalent solar. Founded by former physicists from Lawrence Livermore and Oak Ridge National Laboratories, Zephyr leverages decades of fusion research to deliver a compact magnetic confinement system designed to take advantage of the space environment.

YC batch: F25 · Fall 2025
Status, per YC: Active
Category: Other
Team size: 2
Location: San Diego, CA, USA
Checked: 36m ago

YC tags: Fusion Energy, Hard Tech, Satellites, Aerospace

Zephyr Fusion in F25: 146 companies, 89% AI

Zephyr Fusion: questions

Which YC batch was Zephyr Fusion in?

Zephyr Fusion was in Y Combinator's Fall 2025 batch (F25).

Is Zephyr Fusion still active?

Y Combinator lists Zephyr Fusion as active.

Where is Zephyr Fusion based?

Zephyr Fusion lists San Diego, CA, USA as its location on YC's directory.

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