Propulsion activities

Propulsion is important for maintaining and widening our gateway to space. It takes extreme speed to reach orbit and precisely controlled thrust firing to get a mission where it needs to be. Without propulsion technology, nothing goes anywhere.

Designing the main propulsion system is technically complex and requires interaction with the overall performance and operational capabilities of the Next Generation Launcher.

FLPP identified the enabling critical launcher technologies, which are now being designed at both component and subsystem level to increase their technology readiness level, as intermediate steps prior to an overall integrated demonstration.

The configurations of the planned demonstrators are a result of launcher system and propulsion system analysis and trade-off studies. With a limited budget, they cover a great amount of critical enabling technologies.

This approach has specific benefits:

  • Offers a pool of options and upgrades for quick spin-offs applicable to existing launchers.
  • Performs high added-value research and development.
  • Safeguards propulsion system integration and technology competencies in Europe.

Planned demonstrations

Upper-stage expander cycle demonstrator

Upper stage expander cycle Demonstrator

Launcher studies have shown clearly the need for a versatile, high-performance, evolved cryogenic upper-stage engine capable of delivering payloads to all kinds of orbits, ranging from low orbit to exploration missions in deep space.

A high-performance upper-stage engine appeared to be a central element for the Next Generation Launcher, and a cryogenic expander engine offered high-expectations in terms of performance and reliability.

A number of new technologies are being developed for an advanced upper-stage cryogenic expander cycle engine. These include:

  • advanced turbo-pumps for expander cycle applications;
  • an improved chamber cooling system;
  • ignition system capable of several restarts;
  • ceramic matrix composite extendible nozzle.


The project has achieved the first cryogenic reignitions and closed-loop regulation in Europe, and demonstrated European expertise in the high pressure hydrogen expander cycle. This engine is now the baseline for the next Ariane 5 ME version.

Storable propulsion demonstrator

Storable Demonstrator

A storable propulsion demonstrator, used for a vehicle’s upper-stage and landers in exploration missions, is being developed.

The addressed propulsion category is a 3–8 kN storable pressure-fed engine, for small upper-stage propulsion and versatile orbital propulsion.

Pressure Oscillation Demonstrator – eXperimental (POD-X)

Pressure Oscillation Demonstrator – eXperimental (POD-X)

POD-X is being developed in collaboration with CNES. This versatile demonstrator aims to increase our knowledge of pressure oscillation in solid propulsion engines, such as Ariane 5’s MPS (Moteur Propergol Solide) engine and its possible evolutions.

The results of the demonstration will be applicable to other solid rocket motors, such as those used for the Vega launcher, the NGL and strap-on boosters.

In addition, POD-X will allow the study of other aspects of solid rocket motors, such as new propellant formulations, innovative instrumentation, and new materials for nozzle, igniters and thermal protection.

Hybrid propulsion demonstrator

Hybrid propulsion Demonstrator

Hybrid propulsion is considered as a credible ‘new’ technology to power future operational space transportation systems. It offers a cheap and performing solution by combining the benefits of solid and liquid propulsion.

The demonstrator aims to show the benefits of this technology and increase the readiness level of hybrid propulsion. It could also be used as a preparatory step towards developing an operational engine to power the sounding rockets that are currently planned in Europe.

Last update: 6 March 2014

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