The head of the French space agency CNES told lawmakers in April that a subscale prototype of a future reusable full-flow staged-combustion rocket engine is expected to be tested for the first time in 2028.
CNES President François Jacq disclosed the target in written answers submitted to the French National Assembly’s Economic Affairs Committee ahead of an 8 April 2026 hearing on his proposed reappointment. The questionnaire asked specifically about a contract CNES signed with ArianeGroup on 17 June 2025 for preliminary design work on an engine more than twice as powerful as the Vulcain 2.1 used aboard Ariane 6. The contract was part of the agency’s Advanced Staged-combustion Technologies for Reusable Engines (ASTRE) project.
“The objective is to give Europe the ability, should the need and appropriate circumstances arise, to develop a super-heavy launch vehicle comparable to Starship or New Glenn for missions involving several tens of tonnes,” Jacq explained.
In addition to the subscale hot-fire test in 2028, this phase of the programme includes preparing a preliminary design and development plan for the target engine. A detailed schedule for developing the complete engine would only be outlined once those milestones had been reached. Jacq cautioned that the 2028 test would only represent an early step in a much longer development roadmap.
“It will take more than a decade to develop such an engine and the associated test stand,” Jacq wrote.
Although ArianeGroup is responsible for the largest share of the project, Sirius Space Services is conducting additional technology maturation work, while Pangea Propulsion is developing a separate preliminary design for the target engine.
