• Satellite Evolution Group

ArianeGroup to develop PHOEBUS for ESA


Photo courtesy ArianeGroup

ArianeGroup has received a 50-million-euro agreement from the European Space Agency (ESA) to continue the development of PHOEBUS, a super-light carbon composite upper stage demonstrator. This work will enable development of the next Ariane6 upper stage, by raising the maturity level of cryogenic composite technologies.


The objective is to reduce the weight of the upper stage by using carbon fibre instead of metal for structures such as tanks.


PHOEBUS (Prototype for a Highly OptimizEd Black Upper Stage) is a key programme on the path to a further optimized upper stage called ICARUS (Innovative Carbon ARiane Upper Stage). PHOEBUS is built of carbon composites rather than metal, leading to lower cost and lower weight. It will increase payload capacity and thus contribute to a more sustainable use of resources.


“PHOEBUS will pave the way towards our new ‘Black Upper Stage’ for Ariane 6 and other future launchers, and also help introduce cryogenic composite and liquid hydrogen technologies to the aeronautics sector,” said Karl-Heinz Servos, ArianeGroup Head of Industry. “With support from ESA and in collaboration with MT Aerospace, we are continuing our journey to further enhance the versatility and competitiveness of Ariane 6. We are proud to continue delivering the building blocks for Europe’s new space launch champion, Ariane 6. We are powering European aerospace innovation, driving Europe’s new launcher family, and delivering more sustainable access to space.”


ArianeGroup has worked closely with MT Aerospace to develop design and manufacturing technologies needed to realise cryogenic tanks and adjacent structures in carbon fibre. MT Aerospace has established in Augsburg (Bavaria, Germany) the capacity to manufacture carbon fibre structures and tanks up to 3.5 m in diameter.


Germany’s DLR aerospace institute will be in charge of evaluating the PHOEBUS demonstrator’s performance with cryogenic hydrogen and oxygen at its test centre in Lampoldshausen, Germany.

Together with MT Aerospace, ArianeGroup will develop, build and test the carbon composite PHOEBUS demonstrator in two steps.


The project will first move forward with the manufacturing and testing of sub-scale (2 m diameter) “Technology Control Vehicles” through mid-2023. This will demonstrate the relevant manufacturing processes.


Then, with components manufactured by MT Aerospace, ArianeGroup will undertake assembly and testing of the PHOEBUS demonstrator, which consists of a liquid hydrogen tank mounted on top of a liquid oxygen tank, and is the same size as the future carbon upper stage. The final test – including filling and refueling cycles, pressurization, and drainage – will take place at DLR’s test center in Lampoldshausen (Germany) around the end of 2025. It will be the world’s first demonstration of cryogenic carbon fiber tanks of such a size.


The PHOEBUS project is part of the Future Launchers Preparatory Programme of ESA’s Directorate of Space Transportation.