CNES projects library

January 19, 2021

Themis launcher

Themis is a demonstrator of a low-cost reusable first stage for Europe’s future launch vehicles.

Themis has been designed by ArianeWorks (CNES/ArianeGroup) as a precursor of the first stage of the future Ariane Next launcher that will succeed Ariane 6. An initial development and testing phase got underway under contract with ESA in 2020.

Standing 30 metres tall and 3.5 metres across, Themis will be powered by three Prometheus engines developed by ArianeGroup for ESA. These engines will be built by additive manufacturing and burn oxygen and methane as propellants

The programme is addressing economic, technological and environmental goals. Within the Ariane series’ broader ecodesign strategy, Themis is intended to validate solutions that will reduce the environmental footprint of future generations of launchers, for example by using methane propellant biosourced locally in French Guiana. In Kourou, the Diamant launch pad no longer in use since 1975 will be repurposed for testing of Callisto in 2022 and then Themis in 2023. Themis is drawing on the development of this smaller experimental launch vehicle designed by CNES, DLR and JAXA.

The project is scheduled to run from 2019 to 2025, with the following key milestones:

2019: approval by ESA Ministerial Council

  • 2020: filling and operational refinement tests
  • 2021: first Prometheus engines and hot-fire tests
  • 2022: low-altitude vertical flights from Kiruna, Sweden
  • 2023-2024: flight profiles of a first stage to 60 km from Kourou, French Guiana
  • 2025: addition of new technologies and expansion of flight envelope (Kourou)

Themis launcher tests schedule - Credits: CNES/REAL DREAM