Startupsby GlyphWhy it ranks
How the rank works7signal of 100 · rising 6
- went through YCProgram · this site+4
- team of 2Team size · YC's directory+2.5
A sum of public facts, not a judgement and not investment advice.
Competitors
| Company | Category | Status | Program |
|---|---|---|---|
| Other | Active | YCS14 | |
| Other | Active | YCW25 |
Adjacent
| Company | Category | Status | Program |
|---|---|---|---|
| Other | Active | YCW24 | |
| AI | Active | YCS26 | |
| AI | Active | YCW24 | |
| Other | Active | YCS22 | |
| Other | Active | YCS24 |
Also from F25
All of F25About 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
- 7h ago
YC tags: Fusion Energy, Hard Tech, Satellites, Aerospace
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.