Themis reusable launcher first stage prototype conducts a flight chronology rehearsal

On 23 July 2026, the reusable stage demonstrator Themis conducted a flight chronology rehearsal at Esrange Space Center in Sweden. The ArianeGroup and SSC Space teams have reached a major milestone in preparing for Europe’s first flight test with recovery, known as the Hop Test. Each milestone brings ArianeGroup closer to its goal of giving Europe sovereign capabilities in reusable space technologies.

This rehearsal, also called wet dress rehearsal, marks a key milestone in the development of the launch system, comprising the Themis demonstrator and the ground infrastructure deployed at Esrange Space Center in Sweden.

The objective of the test was to simulate launch operations under cryogenic conditions, including pre-flight preparation of the demonstrator and its launch pad, as well as the system passivation that will be carried out after post-flight recovery.

The rehearsal was conducted with liquid nitrogen replacing the propellants, liquid oxygen and liquid methane, in all cryogenic lines and tanks, enabling the simulation of cryogenic temperature and pressure conditions, as low as -200°C during the test. The chronology simulation lasted a full day for the duration of the countdown and the post-virtual-launch activities of safing the site.

The test has provided essential data for the continuation of the SALTO project implementation and test campaign. The teams are now working to define the window for the next test.

The test campaign in the scope of the EU-funded project SALTO follows a test-and-learn approach. It relies on successive demonstrations to develop and mature the technologies required for reusability. Each milestone marks further progress towards reusable launch technologies in Europe.