Gamchanging Hypersonic Drones from Venus Aerospace and Hermeus

Venus Aerospace and Hermeus are two innovative companies advancing hypersonic technology, focusing on engine efficiency, rapid prototype development, and simplified propulsion systems to operate across speed regions from 0 to Mach 5 and beyond.

Here is analysis of why their technologies and plans should succeed. How will they get more thrust and efficiency and get through three speed regions.

Going from
– 0 to mach 3
-mach 3-4
and then getting to 5+
have often required 3 different engines. The other solution is using a rocket to go from 0 to mach 5 and then releasing a small scramjet engine to power that can a warhead at speeds over mach 5.

Venus Aerospace has new simpler engine with 15% more efficiency which could go from 0 to mach 6 with one engine.

Hermeus is using turbine combined cycle for a two engine in one approach. Hermeus will use a high speed dive to go from mach 3.5 to mach 5. This will remove the need for another engine in the mach 3.5 to 4.5 range.

Both are companies actually rapidly building and testing a series of engines and flyable prototypes. This follows in the tradition of the Lockheed skunkworks which had its rapid development in those times.

XP-80 Shooting Star (1943-1944): The Skunk Works’ first major project began in June 1943, when the U.S. Army Air Forces tasked Lockheed with building a jet fighter prototype to counter the German Me-262. Kelly Johnson promised delivery in 180 days, but his team completed the XP-80 in just 143 days, with its first flight on January 8, 1944. This started Skunk Works’ reputation for rapid prototyping.

U-2 Dragon Lady (1955): In response to a need for a high-altitude reconnaissance aircraft, Johnson’s team delivered the first U-2 prototype in about eight months, with its initial test flight on August 1, 1955. This was critical for U.S. intelligence during the Cold War.

A-12 and SR-71 Blackbird (1959-1962): The A-12, precursor to the SR-71, went from concept to first flight in under three years, flying on April 26, 1962. The SR-71 spyplane had its first flight on December 22, 1964. These timelines were exceptionally fast for such complex, high-speed aircraft.

Clarence “Kelly” Johnson was the visionary founder and leader and Chief Engineer of Skunk Works from 1943 and until his retirement in 1975. His motto “Be quick, be quiet, be on time”. He was a hands on leader of small, highly skilled teams, minimal bureaucracy, and direct control over projects.

This is the same model for success at SpaceX and it appears Venus Aerospace and Hermeus.

BTW: Smaller highly skilled teams with minimal bureaucracy led by a strong technical leader that actually delivers a rapid series of better and better prototypes is what is needed for all advanced technological development (like AI).

Venus Aerospace: Rotating Detonation Rocket Engine (RDRE) Innovation

Engine Technology: Extra Thrust and Efficiency

For hypersonic planes: it is all about how much thrust is created and how efficiently are we doing it as we get more and more speed. Can we keep getting faster and faster without hitting a big gap? Can the engines be light enough?

Venus Aerospace has developed the Venus Detonation Ramjet 2000 lb Thrust Engine (VDR2), which integrates a Rotating Detonation Rocket Engine (RDRE) with a ramjet. This hybrid engine offers several advantages:

Efficiency: The RDRE is 15% more efficient than conventional deflagration-based engines. This improvement arises from its use of a detonation wave to combust the fuel-air mixture, enhancing thermodynamic efficiency. This efficiency could translate to significant fuel savings and a higher thrust-to-weight ratio.

Thrust: The RDRE provides robust thrust from takeoff, a critical capability demonstrated at takeoff speed. By combining this with a ramjet, the VDR2 maintains high thrust across a wide speed range, targeting speeds up to Mach 6.

Transition Advantage: Unlike traditional supersonic ramjets, which require speeds of around Mach 3.5 to operate efficiently, the VDR2 transitions to ramjet mode at Mach 2.5. This lower transition speed enhances efficiency and reduces the complexity of accelerating to hypersonic speeds.

The engine’s design is notably simpler, with no moving parts in the combustion chamber, potentially reducing maintenance costs and increasing reliability.

Speed of Prototype Development and Flight Testing

Achievements: Venus Aerospace, founded in 2020, has made rapid progress. In February 2024, they conducted a subsonic drone flight, reaching Mach 0.9. While not yet supersonic (Mach 1 is the speed of sound), this milestone demonstrates their ability to integrate and test key technologies.

Timeline: They plan to test a hypersonic drone by late 2025, with operational hypersonic drones targeted for 2026 and potentially hypersonic aircraft exceeding Mach 5 by 2028. This aggressive schedule reflects their confidence in the RDRE and VDR2 technologies, supported by successful early demonstrations.

Navigating Speed Regions (0 to Mach 5+) with Simpler Engines

Single-Engine Solution: The VDR2 is designed to operate from takeoff (0) to Mach 6 with a single propulsion system. The RDRE provides thrust for initial acceleration, while the ramjet takes over for high-speed cruising.

Thrust Efficiency: By transitioning to ramjet mode at Mach 2.5, the VDR2 maintains efficiency across a broader speed range than traditional systems, which often require multiple engines or complex configurations. The 15% efficiency gain further ensures sustained performance without excessive fuel consumption.

Hermeus: Turbine-Based Combined Cycle (TBCC) Approach
Engine Technology: Extra Thrust and Efficiency

Hermeus is developing the Chimera, a Turbine-Based Combined Cycle (TBCC) engine that combines a turbojet (using off-the-shelf components like the Pratt & Whitney F100) with a ramjet:

Efficiency: While specific efficiency gains are not quantified as with Venus’s RDRE, the TBCC optimizes performance by leveraging the strengths of both engine types. The turbojet provides efficient thrust at lower speeds, while the ramjet excels at higher speeds. A precooler and bypass system enhance the transition between modes.

Thrust: The turbojet delivers sufficient thrust from takeoff to approximately Mach 3, after which the ramjet takes over. Hermeus employs a controlled dive to accelerate the aircraft to Mach 4, enabling a smooth switch to ramjet mode and bypassing the inefficient speed gap between turbojet and ramjet operation.

Cost and Development Advantage: Using proven off-the-shelf engines reduces development time and costs, prioritizing practicality over groundbreaking efficiency gains.

Speed of Prototype Development and Flight Testing

Achievements: Founded in 2018, Hermeus has advanced quickly with their Quarterhorse project, which includes multiple iterations:
Quarterhorse Mk 1 (2024): Scheduled for flight tests focusing on high-speed takeoffs and landings.
Quarterhorse Mk 2 (2025): Will achieve supersonic speeds up to Mach 2.5, powered by a precooled F100 engine.
Quarterhorse Mk 3 (2026): Aims for speeds exceeding Mach 3.3, incorporating the Chimera II propulsion system.

Timeline: Hermeus has tested the Chimera engine in wind tunnels and is preparing for Mk 1 flight tests in 2024. Their iterative approach accelerates development, with operational hypersonic capabilities targeted for the mid-2020s, potentially with the Darkhorse project following the Quarterhorse series.

Navigating Speed Regions (0 to Mach 5+) with Simpler Engines

Combined Cycle Solution: The TBCC integrates two engine types into a single propulsion system, covering speeds from 0 to Mach 5+. The turbojet handles lower speeds, while the ramjet activates at higher speeds.

Thrust Efficiency: The controlled dive strategy ensures efficient thrust during the transition from turbojet to ramjet, minimizing performance losses. By using established engine components, Hermeus maintains reliability and thrust efficiency without the need for entirely new designs.

Comparative Analysis – Extra Thrust and Efficiency

Venus Aerospace: The RDRE’s 15% efficiency improvement and high thrust-to-weight ratio give it an edge in raw performance. The ability to transition to ramjet mode at Mach 2.5 enhances its versatility.

Hermeus: The TBCC may not match the RDRE’s efficiency gains but offers reliable thrust through proven technology. The controlled dive optimizes the transition, ensuring effective performance across speed ranges.

Speed of Prototype Development and Flight

Venus Aerospace: From founding in 2020 to a subsonic flight in 2024 and hypersonic tests planned for 2025, Venus demonstrates a fast-paced development cycle driven by innovative engine technology.

Hermeus: With a longer runway since 2018, Hermeus’s structured Quarterhorse iterations (2024–2026) reflect a methodical yet rapid approach, leveraging existing engines to expedite testing and deployment.

Navigating Speed Regions with Fewer, Simpler Engines

Venus Aerospace: The VDR2’s single-engine design simplifies propulsion, covering 0 to Mach 6 with high efficiency and fewer components.
Hermeus: The TBCC uses two engine types in a combined cycle, reducing complexity compared to traditional multi-engine systems while effectively spanning 0 to Mach 5+.

Cost Considerations

Hermeus: Estimates suggest operational hypersonic aircraft (possibly Darkhorse) could cost $100 million per vehicle, a competitive figure enabled by off-the-shelf components and reusable designs. This contrasts with single-use hypersonic missiles costing around $106 million each.

Venus Aerospace: Specific cost figures are not provided, but the simpler VDR2 design could lower production and maintenance expenses.

Conclusion
Venus Aerospace and Hermeus are pushing the boundaries of hypersonic flight with distinct strategies. Venus leverages the RDRE’s superior efficiency and a single-engine solution to target Mach 6 by 2028, with hypersonic drones planned for 2026. Hermeus combines proven turbojet and ramjet technologies in a TBCC system, aiming for Mach 5+ by 2026 at a potential cost of $100 million per vehicle. Both companies are great at rapid prototyping and simplifying propulsion. This is why I think they will succeed in making hypersonic travel work in the timelines they have laid out. Venus holds an advantage in engine efficiency, while Hermeus benefits from cost-effective development using established components.

They will succeed with affordable and effective hypersonic technology where other companies and countries have failed for decades.