ESA Themis reusable rocket-stage demonstrator family

Themis is a family of European reusable rocket-stage demonstrators developed by ArianeGroup for ESA. Restartable liquid-oxygen/liquid-methane Prometheus engines, lightweight tanks, guidance and recovery hardware support vertical takeoff and powered vertical landing. The first T1H model supports low-altitude hops, while the planned T1E evolution adds upgraded structures and tanks for longer, higher flights. Themis is a technology demonstrator rather than an operational orbital launch service.