“An upper stage is the last part of a rocket that delivers a payload,” explained Toni Tolker-Nielsen, head of ESA’s space transportation department. “Also called an orbital stage, these elements have, so far, never been reused.” That technical milestone untouched even by SpaceX now sets Europe’s newest push towards reusability of launch vehicles.
Under the International Astronautical Congress in Sydney, the European Space Agency also contracted Italian rocket manufacturer Avio a €40 million ($47 million) to develop a preliminary design and ground infrastructure plan for an orbital stage that can fly to orbit, come back intact, and launch again. The two-year project will yield a basic design and ground infrastructure concept for such a stage. It is a giant step above booster recovery, requiring control of high-energy reentry, accuracy landing, and quick refurbishment skills that have been beyond the reach of all space-faring nations so far.
Avio’s design, shown in an artist’s impression, closely resembles SpaceX’s Starship: a streamlined, stainless-steel-colored profile with four streamlined flaps, sat atop a solid-fueled first stage similar to that of the P120C booster employed on Vega C. At the proportions illustrated, the demonstrator would measure approximately 36.5 meters tall. The appearance suggests propulsive recovery, presumably using clusters of Avio’s methalox MR10 engines technology already under development for future Vega E rocket.
The engineering problem is daunting. In contrast to boosters that can reuse after coming back from suborbital flights, an upper stage has to endure reentry from orbital speed approximately 7.8 kilometers per second without compromising structural integrity and thermal protection for reuse. That necessitates sophisticated heat shielding, sensitive attitude control during descent, and deep-throttling engines for a terminal landing burn. Even SpaceX’s Starship program, with its top-to-bottom methane-fueled architecture, has yet to show a successful orbital recovery of its upper stage.
Avio will draw on its concurrent work on liquid oxygen–methane propulsion and on the reentry vehicle called Space Rider. The MR10 engine for Vega E’s upper stage is a scaled-down version of the company’s MR60 a high-thrust methalox engine in development with funding from the Italian government. The MR60, which has six times the thrust of the MR10, incorporates design concepts inspired by SpaceX’s Raptor, with greater specific impulse and efficiency being important for reuse.
Methane engines are now the propulsion system of choice for the next generation of reusable rockets globally. SpaceX’s Raptor, China’s Long March 9 methalox clusters, and Blue Origin’s BE-4 all take advantage of methane’s clean burning characteristics, limiting coking and increasing flight-to-flight engine life. Europe’s own Prometheus engine from ArianeGroup follows the same philosophy but is still in the design stage, with Avio’s MR10 already having undergone several ground tests.
ESA’s contract is part of a larger strategic shift. The Ariane 6, which will monopolize Europe’s launches for the near future, is an expendable architecture expensive to fly in an environment where SpaceX reuses Falcon 9 boosters on a regular basis. European startups are going after reusable lower stages, and ESA’s Themis prototype is gearing up for low-altitude hop tests in Sweden. But a reusable upper stage, if achieved, would bypass even these endeavors, conceivably paving the way for a fully reusable European launch system.
The stakes go beyond the engineering. Independent access to space is a matter of sovereignty in the eyes of European policymakers, even if that is at the cost of having to pay more than commercial competitors. “We are capitalising on progress made in advanced liquid propulsion, reentry, recoverability, and reusability technologies,” stated Giorgio Tumino, ESA’s chief technical advisor, adding that the work underpins both Vega evolutions and “other newly defined fully reusable launch systems in Europe.”
Avio’s recent separation from Arianespace on marketing Vega launches provides it with greater commercial freedom. CEO Giulio Ranzo positioned the reusable upper stage as part of a drive toward “higher launch frequency and more competitive costs” that tracks world trends toward turnaround vehicles. If the demonstrator works, it might be integrated into Vega E or an all-new platform, rewriting Europe’s competitive standing in the world launch market.
For now, the project remains in its earliest design phase. But the €40 million award signals ESA’s intent to close the technology gap with SpaceX not by replicating Falcon 9’s booster recovery, but by targeting the more elusive prize of orbital-stage reusability.
