Our Technology


Currently, space transportation industry is dominated by two propulsion technologies: the liquid propellant engine and the solid propellant engine. Both of these technologies have their own advantages but they come with tradeoffs and drawbacks. They are far from ideal propulsion systems.

At HyPrSpace, we are working on a third propulsion technology called Hybrid. Hybrid Rocket Engines (HRE) have the potential of featuring the advantages of both liquid and solid propulsion technologies. They could become the best propulsion technology for space transportation in the near future!

The Cornelian dilemma of space propulsion. HyPrSpace wants to create the best of propulsion technologies using Hybrid Rocket Engine.


A HRE consists in using one liquid propellant (usually the oxidizer) and one solid propellant (usually the fuel). The liquid oxidizer is stored into a tank and feeds the combustion chamber which contains the solid fuel grain.

Using HRE, thrust can be modulated by controlling the oxidizer flow rate. Similarly, the engine can be shut down and reignited. Standard HRE have similar specific impulse than common kerolox engine. Solid fuel grain eases the use of metallic additives which can lead to propulsion systems featuring greater specific impulse than H2/O2. HRE is easy to develop and cheap to manufacture due to the low complexity and number of parts. It is also safe to operate. Even in case of failure, the propellants cannot be mixed to undergo violent explosion. This engine is robust and less sensitive to operational condition.


Fact is: HRE doesn’t work yet because of a 50 years old technical barrier. The propulsion is not stable due to the stratification of reactants and the need of higher regression rates in a large combustion chamber for the original engine architectures.

Therefore, at HyPrSpace we develop a completely overhauled engine architecture: as you can see on this schema, the oxidizer tank is now inside the fuel grain tank where the combustion occurs.  By doing so, we obtain a really thin combustion chamber and a simpler engine in general, requiring realistic regression rates and allowing a good mixing of reactants, for a sturdy and stable propulsion.

That design is a unique and patented innovation that led us to win the France 2030 R&D program on microlaunchers, and the support of many important space actors that you can find in the Partners section.