Pressure-Gain Combustion

The science of detonation propulsion.

Detonation engines burn fuel through a supersonic combustion wave instead of a slow flame — unlocking a more efficient thermodynamic cycle than any conventional jet or rocket. Here's how we're turning that physics into hardware.

DEFLAGRATION (CONVENTIONAL) subsonic flame DETONATION (SLEIPNIRX) supersonic shock

Deflagration is slow. Detonation is the upgrade.

Today's engines rely on deflagration — a subsonic flame that burns at roughly constant pressure. Detonation instead couples a shock wave to the combustion zone, burning the mixture almost instantly at far higher pressure.

That pressure gain is the prize: it raises the effective compression of the cycle without extra turbomachinery, which is why detonation engines promise higher efficiency, lower mass and simpler designs across a huge range of vehicles.

Platform 01 · Flagship

Pulse Detonation Engine — PDE

Our near-term flagship: a cyclic detonation engine that is mechanically simple, fast to prototype, and largely untapped commercially — making it our most direct route to a fundable, testable demonstrator.

  • How it works. Fuel and oxidiser fill a tube, are ignited, and a detonation wave races down the chamber. The cycle repeats many times per second to produce thrust.
  • Why we lead with it. Few teams are building PDE hardware commercially. Its simplicity lets a small team reach a meaningful milestone quickly and economically.
  • Best-fit missions. Tactical and expendable systems, upper-stage and kick-stage applications, and research demonstrators.

PDE — indicative characteristics

Combustion modeIntermittent / cyclic detonation
ArchitectureValved or valveless detonation tube
Moving partsMinimal
Operating frequencyTens to hundreds of Hz
Development stageDemonstrator design
Primary advantageSimplicity & speed to prototype

Figures are indicative targets for our demonstrator program, not finalised specifications.

Platform 02 · Core R&D

Rotating Detonation Engine — RDE

A continuously rotating detonation wave inside an annular chamber, producing steady, compact, high-density thrust. The platform with the broadest long-term potential across launch and air-breathing propulsion.

RDE — indicative characteristics

Combustion modeContinuous rotating detonation
ArchitectureAnnular detonation chamber
Thrust profileSteady & continuous
FootprintHighly compact for thrust produced
Development stageApplied research
Primary advantageScalability & power density

RDE science is decades old yet still largely pre-commercial — leaving substantial room for genuine engineering differentiation.

  • How it works. One or more detonation waves travel continuously around a ring-shaped chamber, so combustion never stops — yielding smooth, dense thrust from a small core.
  • Why it matters. Its compactness and scalability make it a strong candidate for launch propulsion and for upgrading air-breathing engine combustors.
  • Best-fit missions. Launch and space propulsion, high-performance defense systems, and next-generation air-breathing engines.
PDE vs RDE

Choosing the right wave for the mission

Both are detonation engines — but they make different trade-offs. We advance them in parallel and select per application.

AttributePulse Detonation (PDE)Rotating Detonation (RDE)
CombustionCyclic / intermittentContinuous
Mechanical complexityVery lowLow–moderate
Speed to prototypeFastestModerate
Thrust smoothnessPulsedSteady
Power densityHighVery high
Best near-term fitDemonstrator & tacticalLaunch & air-breathing
SleipnirX priorityFlagshipCore R&D
Applications

One combustion core, many vehicles

Because detonation combustion is a fundamental upgrade, the same core technology scales across markets.

Space Launch

Higher-efficiency, lower-mass propulsion for launch vehicles, upper stages and kick stages.

Defense Systems

Compact, high-density thrust for tactical, high-speed and expendable platforms.

Air-Breathing Aviation

Detonation combustors that can replace conventional chambers in turbojet and turbofan engines.

UAVs & Drones

Lightweight, simple PDE propulsion for unmanned and autonomous flight systems.

Advanced Research

A platform for foundational work toward future advanced and nuclear propulsion.

Test & Demonstration

Static-fire and flight demonstrators that generate the data partners and grant bodies need.

Engineering Roadmap

A milestone-driven path to flight

Phase 01 · Now

Foundation & demonstrator design

Company formation, core team, market validation and the design of our first detonation demonstrator — anchoring our inaugural research grant.

Phase 02

Static testing

Fire a sub-scale engine on the stand to characterise detonation stability, thrust and thermal behaviour.

Phase 03

In-flight demonstration

Fly the engine with an established platform partner to produce real-world flight data.

Phase 04

Air-breathing & advanced propulsion

Extend the detonation core into air-breathing combustors and begin foundational advanced-propulsion research.

Want the technical deep-dive?

We share detailed engineering material with serious research, investment and integration partners under NDA.