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ArianeGroup Completes Themis Wet Dress Rehearsal
European Spaceflight • • science
Key Points:
- ArianeGroup completed a wet dress rehearsal for the Themis reusable booster demonstrator at the Esrange Space Centre in Sweden on 23 July, marking the first major update in over ten months.
- The 28-meter demonstrator underwent a simulated pre-flight sequence under cryogenic conditions using liquid nitrogen to replicate flight temperatures and pressures, without using the liquid oxygen and methane planned for powered tests.
- The rehearsal included preparations for the vehicle and launch pad, countdown procedures, and post-simulated flight site safety measures, all conducted over one day.
- This milestone is the most significant public update since the Themis T1H demonstrator was erected on landing legs in September 2025, with further testing delayed by seasonal conditions.
- ArianeGroup is currently analyzing data from the rehearsal to plan the next phase, which will involve a low-altitude hop test, but no date has yet been announced.
