Velontra
YC S22Cincinnati, US · Founded 2021 · Delaware corporation · 5 employees · 3 known investors
Velontra develops jet propulsion systems across the Mach spectrum, focusing on low-cost, high-volume manufacturing through vertically integrated design and rapid development cycles.
Advanced ManufacturingDeep TechDefense TechHardwareSpace TechCommercial Space LaunchDronesAerospaceUnited States of AmericaAmerica / CanadaPartly Remote
Founders & leadership· Y Combinator alumni (S22)
Velontra was founded in 2021 by Joel Darin, Robert Keane III, and Zachary Green.
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Joel Darinin𝕏Co-founder · Chief Executive OfficerJoel Darin worked as the first employee at Hermeus, where he designed and tested turbine-based propulsion prototypes, and previously held roles in afterburner design at GE Aviation. He holds a master's degree in combustion from Georgia Tech and a bachelor's degree in mechanical engineering from Michigan State University.
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Robert Keane IIICo-founder
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Zachary GreenCo-founder
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Eric BriggsChief Operating Officer
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Mark H. Longenecker Jr.Executive
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Craig WheldenExecutive
Investors · 3
Reported raises · per SEC filings
Form D private placements$400K disclosed across 2 rounds · 2021–2025
▶$250KraisedMar 2025 · 1 investors · Other TechnologyRule 506(b)
▶$250KraisedMar 2025 · 1 investors · Other Technology
Rule 506(b)Officers, directors & promoters on the filing
- Eric BriggsExecutive Officer, Director
- Joel DarinExecutive Officer, Director
- Offering amount
- $250K
- Amount sold
- $250K
- Minimum investment
- $50K
- First sale
- Feb 2025
- Incorporated
- Corporation, Delaware, 2022
- Federal exemptions
- 06b
▶$150KraisedJun 2021 · 2 investors · Other Technology
▶$150KraisedJun 2021 · 2 investors · Other Technology
Officers, directors & promoters on the filing
- Joel DarinExecutive Officer, Director
- Mark H. Longenecker Jr.Executive Officer
- Robert Keane IIIExecutive Officer, Director, Promoter
- Zachary GreenExecutive Officer, Director, Promoter
- Craig WheldenExecutive Officer
- Offering amount
- $3M
- Amount sold
- $150K
- Minimum investment
- $50K
- Proceeds to insiders
- $700K
- First sale
- Jun 2021
- Incorporated
- Limited Liability Company, Ohio, 2021
- Federal exemptions
- 04
Source: SEC EDGAR Form D. Amounts as filed; amended filings shown once at their latest values.
Non-dilutive funding · 4 SBIR/STTR awards
Federal grants — no equity taken| Agency | Phase | Year | Amount |
|---|---|---|---|
| U.S. Air ForceAir Force | Phase I | 2023 | $74.7K |
| U.S. Air ForceAir Force | Phase I | 2023 | $74.7K |
| U.S. Air ForceAir Force | Phase II | 2022 | $750K |
| U.S. Air ForceAir Force | Phase ISTTR | 2022 | $49.7K |
Source: SBIR.gov award data (U.S. Small Business Administration). SBIR/STTR awards are competitive federal R&D grants and contracts — non-dilutive capital alongside any venture rounds above.
In the news
Frequently asked questions
- What does Velontra do?
- Velontra develops jet propulsion systems across the Mach spectrum, focusing on low-cost, high-volume manufacturing through vertically integrated design and rapid development cycles.
- Who founded Velontra?
- Velontra was founded by Joel Darin, Robert Keane III, Zachary Green in 2021.
- Who are Velontra's investors?
- Velontra's investors include Sica Ventures, Y Combinator, Soma Capital.
- How much funding has Velontra raised?
- Velontra has disclosed $400K raised across 2 rounds.
- Where is Velontra headquartered?
- Velontra is headquartered in Cincinnati, US.

