Venus Aerospace Closes $91 Million Series B Financing Led by Mercury Fund

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After completing the world's first successful flight test of a high-thrust rotating detonation rocket engine (RDRE) in May 2025, Venus Aerospace today announced the close of a $91 million Series B financing led by Mercury Fund, a Houston-based venture capital firm, with participation from Lockheed Martin Ventures, MESH, PEAK6, Draper Associates, Starboard Star Venture Capital, Green Sands Equity, Seraph Group, Trousdale Ventures, and other new and existing strategic and institutional investors.

The round will fund Venus as it scales development and production, moving its RDRE propulsion system from successful flight demonstration toward deployment for a range of near-term defense and space applications. Current systems struggle to meet customer requirements for range, performance, and domestic production. Venus is building to close that gap.

The announcement follows the recent appointment of Pam Melroy, former NASA Deputy Administrator, to Venus' board of directors.

Unlike conventional rocket engines, which burn fuel through subsonic combustion, Venus' RDRE employs a continuous supersonic detonation wave that rotates around the combustion chamber. The result is the most efficient rocket engine architecture ever flown, by a margin of 15 percent. This efficiency gain can translate into extended range, increased payload flexibility, and more capable systems across defense and space missions where performance margins are critical.

Built from 3D-printed components and standard materials, the RDRE is designed for domestic manufacturing at scale through accessible supply chains, reducing reliance on constrained or foreign-sourced parts. The engine is reusable and throttleable, with a wide range of mission applications, from munitions and space launch to orbital transfer and landers. Rather than developing a different engine for each application, Venus is building a common propulsion architecture intended to serve across multiple mission classes.

Demand for hypersonic and long-range capability is accelerating as the U.S. and its allies move to field systems that can reach farther and fly faster than legacy platforms allow. Venus is building its engines in Texas with American engineering talent for customers whose missions depend on reliable, sovereign propulsion capability.

"This financing marks an important step in moving Venus from breakthrough demonstration to scaled capability," said Sassie Duggleby, co-founder and CEO of Venus Aerospace. "Our customers need propulsion systems that go farther, can be produced reliably and are built on supply chains they can trust. We are advancing that capability with American engineering and manufacturing talent to strengthen U.S. defense, expand space access and support the future of high-speed flight."

"Venus is exactly the kind of company Houston capital should be backing," said Blair Garrou, co-founder and Managing Partner at Mercury Fund. "It combines multiple frontier technologies, domestic manufacturing and clear commercial and national security relevance. We believe this team is positioned to lead an important new chapter in defense and space, and we are proud to support a company building breakthrough technology here in Texas."

"Lockheed Martin Ventures invests in technologies to help increase mission effectiveness," said Chris Moran, vice president and general manager of Lockheed Martin Ventures. "Since our initial investment, Venus has progressed very quickly in its technology development. Our reinvestment in Venus recognizes Venus' accomplishments to date and focus on speed to manufacture, cost management and reduction of supply chain constraints. Venus is working effectively to position its propulsion system for the production scale required by defense programs."

"This capital allows us to move from successful flight demonstration toward deployable propulsion systems," said Andrew Duggleby, co-founder and CTO of Venus Aerospace. "What differentiates our RDRE is not just that it works, but that it has flown at high thrust and was designed with scale, manufacturability and mission integration in mind. Our propulsion architecture combines efficiency, throttling, reusability and manufacturability in a way that customers need for real defense and space missions. We are focused on translating technical progress into reliable systems for operational use."

Venus conducted the world's first flight test of a high-thrust rotating detonation engine in May 2025, reaching that milestone in just over four years on $80 million in capital, one of the fastest and most capital-efficient engine development efforts of its kind.