ESA Space Transportation

For its most powerful flight yet, Ariane 6 lifts off for the first time with four boosters.

Designed for versatility, Ariane 6 can adapt to each mission: flying with two boosters for lighter payloads, or four boosters when more power is needed.

In its four-booster configuration, Ariane 6 can carry larger and heavier spacecraft into orbit, enabling some of Europe’s most ambitious missions — such as Argonaut.

Romanian company ATD Aerospace RS SRL is developing a 10 kN rocket engine that can be re-ignited and adjust its thrust. This builds on the 1 kN engine they developed with support from the European Space Agency (ESA).

Before working with ESA, ATD had already created several engines in the 0.5–1 kN range, which paved the way for their later developments. This project is part of ESA’s Future Launchers Preparatory Programme (FLPP), that helps develop the technology for future for space transportation systems. By conceiving, designing and investing in technology that doesn’t exist yet, this programme is reducing the risk entailed in developing untried and unproven projects for space.

The firing test seen here shows a water-cooled version as it cycles from 100% thrust to 60% and back to 100%. The test, conducted in Romania in 2025 saw the engine perform as expected. The engine uses hypergolic propellants, which are ideal for spacecraft or rockets that need to store fuel for extended periods.

Turned upside down, the engine could suspend 1000-kg on Earth, the weight of typical hippopotamus. Used as intended it could slow the descent of a rocket stage and ensure a soft touchdown.

Various sensors were used during the test firings to characterise the engine and its functions.

The development involves three designs, starting with an uncooled engine demonstration, a next version that is cooled with water, as seen in this video, and finally a self-contained engine that incorporates its own cooling.

The European Space Agency is financing the development up to the successful test of the final regenerative cooled-engine, reaching a technology readiness level of five with a smaller-scale test firing (TRL5).

Animation showing a possible interoperability application in orbit of payload deployment and retrieval operations with ESA’s reusable Space Rider. 

Space Rider is a versatile uncrewed robotic laboratory about the size of two minivans. This video shows operations of how Space Rider could fly to an orbital platform and deliver payloads using a robotic arm as well as retrieving other payloads to return them to Earth. In the near future platforms orbiting Earth could allow for cheap and efficient experimentation and research in the low Earth-orbit economy. Whereas Space Rider could stay in orbit for two months, by delivering payloads to orbital platforms like this the hardware could stay in orbit for as long as needed and also be retrieved and returned to Earth, allowing for manufacturing in space, to benefit research in pharmaceutics, biomedicine, biology and physical science. 

The animation uses some artistic license to show how the operations could be carried out. In reality for example the rendezvous between Space Rider and the orbital platform would require Space Rider to arrive from a lower orbit. 

At the end of its mission, Space Rider will return to Earth with its payloads and land on a runway to be unloaded and refurbished for another flight.  

On 17 December, two new Galileo satellites lifted off from Europe’s Spaceport in French Guiana aboard an Ariane 6 rocket. This marked the 14th launch for Europe’s satellite navigation operational satellite programme, reinforcing Europe’s resilience and autonomy.

The European Space Agency (ESA) is responsible for carrying out the Galileo launch with Arianespace on behalf of the European Commission. The Galileo satellites were manufactured by OHB, under contract with ESA. Once in orbit, the EU Agency for the Space Programme (EUSPA) will bring the satellites into service and oversee their operation.

The flight, designated VA266, was the first launch of Galileo satellites on Europe’s newest heavy-lift launcher Ariane 6.

Follow the launch campaign. 

Access the related broadcast quality video material. 

On 26–27 November, the ESA Ministerial Council will take place in Bremen, Germany. Key decisions will be made about the future activities of the European Space Agency within the frame of ESA’s Strategy 2040. Toni Tolker-Nielsen outlines how these decisions will shape the future of Space Transportation Systems.