Originally Posted by en.wikipedia.org/wiki/ARCAspace

EcoRocket Demonstrator
The EcoRocket Demonstrator (formerly just EcoRocket) is a partially-reusable three-stage orbital launch vehicle currently under development. The EcoRocket Demonstrator had been slated to launch in 2022, however, no launch took place that year. The vehicle's reusable first stage will use a battery-powered steam rocket to propel a small second stage to an altitude of 7 kilometers. The second stage will then proceed to a higher altitude to deploy a smaller third stage, carrying the payload. The third stage utilizes RP-1 and high test peroxide to propel a payload of up to 10 kilograms into orbit. The rocket takes its name from the claimed ecological benefits of not burning as much kerosene (despite using kerosene to achieve most of orbital velocity).[38] The EcoRocket will launch partially submerged in the Black Sea, in a similar manner to the Sea Dragon.[39] Both the first and second stages are intended to be reusable, parachuting back into the ocean for recovery. The vehicle is intended to demonstrate technologies for the upcoming EcoRocket Heavy.