The European Space Agency (ESA) has commissioned a new all-carbon-composite upper stage to be used in conjunction with the Ariane 6 rocket. Designated Phoebus, the next-generation upper stage could boost the rocket’s payload capacity to geosynchronous orbit by up to two metric tons.

On May 14, representatives from MT Aerospae and ArianeGroup signed contracts with the ESA to develop the Prototype of a Highly Optimised Black Upper Stage (Phoebus). By utilising a lightweight carbon composite material, the new upper stage will not only outperform the aluminium alternative but it will also cost less to produce. As a result, with the addition of the next-generation upper stage, the Ariane 6 becomes a more affordable and more capable launch vehicle.

“Future composite upper stages will look very different to those of today,” said ESA Project Manager, Josef Wiedemann. “Carbon composites will replace much of the metal thereby reducing the mass and offering new opportunities to redefine the architecture of the upper stage depending on mission requirements.”

In May, ESA member states voted to allocate €70 million ($78 million) to the development of lightweight upper stage technologies. A portion of these funds are reportedly being channelled into the two Phoebus contracts. A spokesperson for MT Aerospace parent company, OHB revealed that the company has received 8.6 million in funding. It is unclear how much ArianeGroup has received and how much has been diverted to other similar projects.

A Phoebus stage demonstrator that can be used for cryogenic ground testing purposes is expected to be ready by 2022. The agency hopes to then have an operation stage to launch aboard an Ariane 6 by 2025.





