Ariane news

Themis and Prometheus® ready to blaze a trail 05-20-2022 |  3 minutes


After a cryogenic test campaign in 2021, the next step in the Themis program is assembly of the Prometheus® engine with the reusable stage demonstrator

© ArianeGroup/Pepper Box/Thierry_MAMBERTI


Themis and Prometheus® are two crucial players in the future of European space and came together on the test bed on ArianeGroup’s Vernon site.

Themis is a full-scale demonstrator of a reusable stage for future European launchers, the purpose of which will be to develop, experiment, and validate all the technological solutions for reuse of a complete stage. It will be equipped with the new Prometheus® engine, precursor of future engines for Europe’s launchers, that will be able to adapt to any type of mission thanks to its variable thrust and multiple reignition capability.

© ArianeGroup/Pepper Box/Thierry_MAMBERTI


The Prometheus® engine was placed below the two propellant tanks of the Themis demonstrator (without its exterior tube). The engine uses a combination of liquid oxygen and liquid methane. 

© ArianeGroup/Pepper Box/Thierry_MAMBERTI


Assembly is now complete and the next step will be the upcoming hot-fire tests during which Prometheus® will be ignited repeatedly over the course of a few seconds, to test its reliability and performance.

© ArianeGroup/Pepper Box/Thierry_MAMBERTI


View of the flame trench dug under the installation to channel the exhaust gases during the hot-fire tests. 

© ArianeGroup/Pepper Box/Thierry_MAMBERTI


The teams posing with Prometheus® encased in its metal framework after installation on the Themis demonstrator.

© ArianeGroup/Pepper Box/Thierry_MAMBERTI


The teams celebrating successfully passing this new milestone. One particularity of the Themis project is that the engine and stage are being developed and implemented at the same time rather than one after the other, thus bringing down development lead-times and costs.


Watch this space for hot-fire test news coming soon!


Themis is a European Space Agency (ESA) program allocated to ArianeGroup, initiated by ArianeGroup and the French space agency CNES.

Prometheus® is being developed by ArianeGroup under an ESA contract at the Ottobrunn (Germany) and Vernon (France) sites.