ArianeGroup has brought the main elements of the Themis reusable booster demonstrator together for the first time during a “full-fit check.” This milestone paves the way for the demonstrator’s inaugural test, which is expected to take place in 2025.
Themis is a 28-metre tall reusable rocket stage demonstrator developed by ArianeGroup under an ESA contract. It is designed to test vertical launch and landing capabilities, integrating key technologies like the Prometheus engine, a low-cost, reusable methalox rocket engine. The project is expected to serve as a critical building block for future European reusable launch systems.
On 17 December, ESA announced that ArianeGroup had completed a full-fit check of the major elements of the Themis demonstrator at its facility in Les Mureaux, France. This stage of the demonstrator’s development ensures that its primary elements fit together as planned, confirming the mechanical connections and interfaces work smoothly and as intended. According to ESA, the full-fit check is one of the final steps in the development phase of Themis.
The specific version of the demonstrator being assembled is the T1H, which stands for Themis 1-Engine Hop. This version of Themis will conduct initial low-altitude hop tests at the Esrange Space Center in Sweden next year. In November, ESA announced that it would build a second Themis demonstrator called T1E (Themis 1-Engine Evolution). This version of Themis will be utilized for medium-altitude tests from Esrange.
After initial testing at Esrange is completed, a three-engine variant of the demonstrator will be launched from a new facility being built at the historic Diamant launch site on the grounds of the Guiana Space Centre. This test campaign will culminate in a full flight envelope test, with the demonstrator launching from the Guiana Space Centre and landing on a barge positioned in the ocean downrange.
