ArianeGroup has announced that the first Themis reusable rocket demonstrator has been fully integrated and is on its own four legs on a launch pad in Sweden. The demonstrator will now be put through a combined test campaign before an initial low-altitude hop test is performed.
ESA Member States adopted the Themis programme in November 2019 with the aim of developing and maturing key technologies for future reusable rockets. The reusable rocket first stage demonstrator stands 30 metres tall and is powered by a Prometheus rocket engine, which is being developed by ArianeGroup as part of a separate ESA-funded project and is capable of producing approximately 100 tonnes of thrust.
In addition to funding from the European Space Agency, the project is also being funded through a European Union initiative called SALTO. According to ArianeGroup, the €39 million project aims to facilitate the first flight tests of the Themis reusable stage demonstrator at the Esrange Space Center in Sweden.
On 19 September, ArianeGroup announced that it had completed the integration of the first Themis prototype after it arrived at Esrange in late June following a 3,000-kilometre road trip from the company’s facility in Les Mureaux, France. After integration was completed, the prototype was transferred to Launch Complex 3 and erected on its launch pad.
With the prototype now integrated and on the launch pad, ArianeGroup will proceed with the combined tests, which will validate the interfaces between Themis and the pad’s mechanical, electrical, and fluid systems. This phase of testing will culminate in a full cryogenic test. Once this test campaign is concluded, the company will be able to move ahead with the first low-altitude hop test.
This first Themis prototype, designated T1H, features a single Prometheus engine and is intended for low-altitude hop tests from Esrange. In November 2024, the European Space Agency awarded ArianeGroup €230 million in additional funding to develop the upgraded T1E prototype, which will be used for higher-altitude and longer-duration flights from the same launch facility. A third configuration, T3, will feature three Prometheus engines and will be used to validate the full flight envelope during launch and recovery tests at the Guiana Space Centre in French Guiana.
European Dignitaries
On 18 September, 13 members of the European Parliament’s Committee on Industry, Research and Energy (ITRE) visited the Esrange Space Centre, likely timed to allow the delegation to inspect the Themis prototype on its launch pad. The ITRE committee is responsible for energy, research and innovation, industry and small and medium-sized enterprises (SMEs), telecommunications, cybersecurity, and, most notably in this instance, European space policy.
“This visit is particularly special as we witness the Themis prototype, Europe’s first large reusable launcher prototype,” said Christophe Grudler, head of the European Parliament’s ITRE committee delegation. “Preparing for its first hop tests, Themis shows that Europe can rise to the challenge of reusable launchers, a technology that is reshaping global competition in space. Success here would be a milestone for Europe’s strategic autonomy and industrial leadership.”
Despite his optimism, Grudler added in a social post on 19 September that in order to go “all the way,” Europe needed an ambitious European budget for space.