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.

New challenges are emerging with the need to cope with lower launch prices worldwide while simultaneously maintaining the high reliability European launchers are known for.

FLPP identified the enabling critical launcher technologies to tackle these challenges and offers solutions via maturation of the technology readiness level for future propulsion systems. Key technologies are designed at both component and subsystem level prior to being integrated into propulsion demonstrator engines and tested in a relevant environment. 

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.

Upper stage engine technologies

Expander-cycle Technology Integrated Demonstrator

After the Vinci engine development was transferred to the Ariane 5 ME development programme, the Expander-cycle Technology Integrated Demonstrator (ETID) began mid-2013.

It is a major constituent of the FLPP programme and prepares competitive evolutions of upper stage propulsion for Ariane 6 and Vega by assembling technologies that pave the way for the next generation of cryogenic upper stage engines in Europe.

ETID addresses the following requirements: 

  • High Isp
  • Low cost
  • Low mass
  • High versatility
  • Easy integration and control
Laser igniter

This engine demonstrator combines several new technologies. Among them is an optimised combustion chamber design for maximum lifetime and heat pick-up which simultaneously avoids water condensation.

In addition, the engine aims for reduced production times and low cost and makes use of Additive Manufacturing (3D-printing) for the injector head, valve casings and parts of the turbo pumps.

The ignition can be realised via either a spark or novel laser igniter.

Nozzle and engine lines are designed for lower weight making use of a sandwich nozzle with radiative nozzle skirt as well as novel materials.

Demonstrator test bench in Germany

The valves are electrically actuated and the engine controller is able to conduct automated check-outs and closed-loop operation point control.

The engine is currently in the hardware manufacturing phase and will be tested at the DLR German Aerospace Center test facility in Lampoldshausen, Germany, in 2017.

Storable propulsion

Storable propulsion

The Storable Propulsion Technology Demonstrator helps develop technologies for a rocket engine in the thrust range between 3–8 kN. The technology developed in this project can be used in upper stages of small launchers or applications with similar thrust requirements like exploration missions or lander engines.

The demonstrator uses novel cooling-, injector- and damping technologies. In two test campaigns, first in 2014 and then in 2015, it performed both ground level as well as vacuum ignitions. Steady state behaviour was tested in a large range of operating points and for durations of up to 110 seconds. In addition, combustion stability and thrust chamber length variations were tested.

Future developments will investigate options to adapt the engine for the combustion of storable green propellants which are more environmentally friendly and drastically reduce the necessary safety precautions for propellant handling.

Hybrid propulsion

Unitary motor 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 increases the technology readiness level of hybrid propulsion. Furthermore, it could serve as a preparatory step towards developing an operational engine to power sounding rockets currently planned in Europe.

Initiated in 2010 the Unitary Motor (UM) propulsion demonstrator was developed within FLPP. Following several small scale tests the first large scale hot fire test was successfully achieved in 2014.

The hybrid engine combines liquid hydrogen peroxide with solid HTPB fuel and reaches a thrust level of 30 kN. It will power the Nucleus demonstrator, a single stage sounding rocket, developed around the engine for in-flight testing in the near future.

Solid propulsion

Testing solid propulsion

Efforts concerning solid propulsion focus on the development of technologies for future motor casings (within the Systems and Technologies section of FLPP) and the investigation of the physics of solid rocket motors, especially pressure oscillations via integrated demonstrators.

The “Pressure Oscillation Demonstrator eXperimental” (POD-X) is an experimental platform dedicated to the investigation of combustion physics and was test fired in cooperation with CNES in 2014, yielding valuable information into solid propulsion combustion processes.

Methane engine

Methane is a candidate for the propellant of the future. Combining high efficiency with operational simplicity while at the same time being environmentally friendly and widely available, it offers unique perspectives as a low cost engine design for first and second stage applications.

Compared to kerosene, methane causes no combustion residuals within the rocket combustion chamber and turbo machinery which makes it a perfect candidate for a reusable booster engine. While several methane development studies are currently on-going in Europe, the addition of a methane demonstrator to the FLPP portfolio is intended for the near future.

Anticipating the future…

Further project proposals include a reusability demonstrator for the next generation launch vehicle that will aim at maturing the relevant technologies for the reuse of first stages or respective sub-systems and thus lowering launch costs in the future.

Moreover, a kick-stage demonstrator could address the need for increased versatility regarding mission profiles. Potential applications are payload injections into multiple orbits, GTO-GEO transfer manoeuvres, as well as satellite servicing and debris deorbit applications. Electrically powered, pump-fed engines are an interesting technology to be considered in this context.

Another interest lies in the creation of a dedicated micro launcher to inject small payloads into custom orbits. This field will be addressed via feasibility studies. At the same time, multiple developments by private industry are currently taking place in Europe offering the long-term potential for spin-in solutions.

Last update: 30 November 2016

Copyright 2000 - 2017 © European Space Agency. All rights reserved.