Faced with SpaceX, Europe is trying to get back into the race for reusable, automatic and habitable gear. ArianeGroup has an upper-stage project for Ariane 6 that ticks all these boxes: Susie.
It is a concept that gives an indication of the path that Europe could take in terms of aerospace. On the sidelines of International Astronautical Congresswhich is being held in Paris from September 18 to 22, 2022, ArianeGroup presented Susie, a proposal to design a “fully reusable” upper stage capable of accommodating cargo or a crew.
A habitable, reusable and automatic upper stage
Susie, an acronym for Smart Upper Stage for Innovative Explorationis dedicated to supporting future European launchers, primarily Ariane 6 (whose maiden flight is expected in 2023), then Ariane Next, a code name for the rocket that will succeed it in about ten years. Ariane 5 will not benefit from it, neither will Vega.
As the upper stage, Susie will take the place of the fairing that sits atop the Ariane rockets. This headdress is made up of two pieces. They separate and are ejected when the rocket reaches an altitude high enough that it is no longer necessary to protect the payload (a satellite, for example) from the friction of the air during the atmospheric crossing.
In the visuals shared by ArianeGroup, we notice that Susie looks a bit like the American space shuttle, with an opening at the level of the central body, with two leaves diverging on each side. This makes it possible to release a payload in space, but also to astronauts to work without having to move away from the vehicle.
Other artist views show Susie able to interface with the International Space Station (ISS), similar to other cargo ships that carry crews or bring supplies. Another scene shows the upper stage in orbit, waiting for another vehicle. This one then “clips” to Susie and the whole thing goes in the direction of the moon.
Susie could thus participate in the Artemis program of the American space agency, which consists in bringing astronauts back to the satellite, by conveying personnel to the lunar space station, in orbit. Susie is described as being able to accommodate five people on board. By comparison, Soyuz has three seats and Crew Dragon seven.
The Susie Floor” is based on the in-depth study of Europe’s future needs in terms of space transport and in-orbit services, and on the need for a profound change in the logic of access to space “says ArianeGroup. It remains a concept, which will evolve until its final version – we can therefore expect notable differences with what is shown today.
These general characteristics however include the possibility of being controllable either by a crew or automatically. The floor will have to assume many types of missions whether they are inhabited or not. The device must be reusable, which implies a controlled re-entry capacity in the atmosphere and a controlled landing on land or sea.
Among the additional faculties expected, in addition to all those already mentioned, Susie could also be used to ” contribute to in-orbit debris reduction and the withdrawal or de-orbiting of end-of-life satellites to tow satellites, inspect them or upgrade them. In short, Susie comes across as a real “ swiss army knife floor “.
An upper stage for the launchers of the future
Susie is intended for the heaviest European launchers (hence Ariane 64 and the absence of a project involving Vega, which is a light launcher), due to its large mass (25 tonnes) and its consequent dimensions (12 meters in long, 5 meters wide). The inner bay has a volume of 40 m3 and the machine has the ability to bring more than seven tons of payload back to Earth.
The specifics of Susie appear to be influenced by the trajectory taken by a growing part of the aerospace sector. For a few years now, we have heard more and more about launchers or segments of launchers capable of navigating autonomously, of automatically returning to Earth if necessary and of re-serving several times.
SpaceX is obviously the name that comes up the most. The American company has acquired an undeniable lead and expertise, but Europe is coming back into the race. In addition to Susie, we know of the existence of several projects, such as Callisto and Themis, which tend to prepare the ground for future reusable and automatic launchers from Europe. We think of Ariane Next, again.
It is absolutely not sure that Ariane 6 will take this path, since the rocket was not developed in this direction from the very beginning. Could future developments reorient the operation of the launcher? That remains to be seen, especially since it might not be worth it with the relative proximity of Ariane Next, which is expected from 2030.
It now remains to be determined what will be the follow-up to this concept. ArianeGroup has been working on the subject for years, it is recalled. The beginnings of this promising stage will at best not take place until 2023, when Ariane 6 will take its first steps. This is a hypothetical calendar: ArianeGroup refrains from giving a date in its announcement.