目前的计划是Callisto 2020, Themis 2025, Ariane Next 2030
hen Themis, which will also be a reusable floor demonstrator, but " much closer to 'an operational stage that is Callisto '. Scheduled in 2025 and 10 times heavier than Callisto, Themis will use the Prometheus engine " in a configuration with one or even three engines ".