Houston's Venus Aerospace Raises $91M for Engine

The Series B funding aims to scale a detonation rocket engine toward production, with a hypersonic aircraft targeted for the early 2030s.

Updated on Nov. 6, 2026 in Startups

Photograph of a bare steel rocket engine nozzle on a concrete test stand with a hazy Gulf Coast industrial horizon behind it. — Houston-based Venus Aerospace raised $91 million in a Series B round led by Mercury Fund to scale its detonation rocket engine toward production. AI Illustration. Upload story photo >

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Houston-based Venus Aerospace announced a $91 million Series B funding round on July 8, 2026, led by Mercury Fund with participation from Lockheed Martin Ventures. The money is meant to move its Rotating Detonation Rocket Engine from flight demonstration toward a scalable, manufacturable system; the engine's 2025 flight demonstration is complete, but the reusable hypersonic aircraft it would power remains research-stage.

Why it matters

The round signals investor confidence that detonation-based propulsion can move beyond a single demonstration toward production hardware. For the hypersonic passenger concept, the engine is an early building block, and the timeline for a flight vehicle is still years out.

The $91 million figure is a company-announced funding total, and the 2025 RDRE flight demonstration is the only completed hardware milestone cited. The Stargazer M4's Mach 4 cruise, roughly 4,900 kmph, is a design target rather than a demonstrated result, and the company has not reported performance of a full hypersonic vehicle.

The players

Venus Aerospace

Houston-based propulsion startup developing the Rotating Detonation Rocket Engine and the proposed Stargazer M4 hypersonic aircraft.

Mercury Fund

Houston-based venture capital firm that led the Venus Aerospace Series B round.

Lockheed Martin Ventures

Venture arm of aerospace and defense contractor Lockheed Martin, which participated in the Series B round.

The details

The rotating detonation rocket engine burns fuel in a continuous detonation wave that travels around an annular chamber, rather than in the steady combustion of conventional rockets, which can extract more energy from each unit of propellant. In the proposed Stargazer M4, the engine would provide initial acceleration after a runway takeoff, and once the aircraft reached supersonic speed, it would switch to a detonation-based ramjet that compresses incoming air for combustion. Those transitions between propulsion modes are the central engineering challenge the company has not yet shown at aircraft scale.

2020: Venus Aerospace founded by Sassie Duggleby and Andrew Duggleby.
2025: RDRE flight demonstration completed.
July 8, 2026: Series B funding round announced.
Early 2030s: First uncrewed Stargazer flight test discussed.

The Tech Race

Detonation-cycle propulsion is pursued as an alternative to steady-combustion rocket and jet engines, which is why a flight demonstration and a defense-linked investor both matter. Lockheed Martin Ventures' participation places the RDRE within the broader race to build faster and more efficient air and space propulsion.

The engine and aircraft are not available to passengers or customers, and no commercial availability date has been announced. Near-term effects are limited to the company's development work and the investors and suppliers involved in it.

The takeaway

Watch for whether Venus Aerospace reports RDRE results beyond its 2025 flight demonstration, since a manufacturable engine would be the first step the company itself has tied to the Stargazer program. The first uncrewed Stargazer flight test, discussed for the early 2030s, is the milestone that will show whether the hypersonic aircraft concept is advancing.