Themis during second wet dress rehearsal

ESA’s Themis reusable rocket stage demonstrator successfully completed its second ‘wet dress rehearsal’ at Esrange Space Center in Sweden on 29 September, testing the vehicle and ground procedures under representative cryogenic conditions.

The second wet dress rehearsal allowed teams from SSC Space and Themis prime contractor ArianeGroup to rehearse operations with the demonstrator on the launch pad.

Themis is a European Space Agency (ESA) rocket prototype – a flagship European demonstrator for low-cost rocket recovery and reuse technologies. Powered by the reusable, liquid oxygen and methane-fuelled engine Prometheus, Themis is on the launch pad at the Esrange Space Center in Sweden operated by SSC Space.

The 29 September rehearsal followed a first wet dress rehearsal held in July and allowed the operators at SSC Space’s launch facility and prime contractor ArianeGroup engineers to practice countdown procedures. The rocket prototype was filled with liquid nitrogen cooled down to –200°C to test the whole system and see how it holds up under the extreme cold and highly-pressurised systems as well as checking if all systems work correctly in these conditions.