ESA's Ariane rockets: Updates on Reusable Engines and Final Launch Date.

ArianeGroup has achieved full ignition of an early prototype of Prometheus, a reusable engine for European rockets, at its test facility in Vernon, France. The engine features extensive use of new materials and manufacturing techniques designed to reduce its cost to just a tenth of Ariane 5’s Vulcain 2. Prometheus burns liquid oxygen-liquid methane fuel, and a version using liquid hydrogen-liquid oxygen is also being developed. The engine is mounted in a prototype of a reusable rocket stage, called Themis, which is being developed in parallel with the engine.