The combined Ariane 6 launcher task force, consisting of ESA, CNES, and ArianeGroup, has reported on the progress of Ariane 6, the steps to launch, and the beginning of stage shipments to the launch site.
The Canopée ship, which Ariane and ESA use to transport the massive rocket, will collect the first and second stages from France and Germany, respectively. ESA reports that the first flight remains on track, targeting a launch window between June 15 and July 31, 2024.
The first flight will feature several small rideshare payloads on top of the Ariane 62. These include the SpaceCase technology demonstrator, the small 1U ISTSAT CubeSat, and many more.
“We will be sharing more about the payloads in February… There will be CubeSats and some payloads from NASA,” ArianeGroup told NSF.
During a factory visit of both the second stage facility in Bremen, Germany, and the first stage facility in Les Mureaux, France, NSF was able to interview high-level officials of the Ariane program as well as ESA Acting Director of Space Transportation Toni Tolker-Nielsen.
The first stage
The first stage of the Ariane 6 rocket is assembled in Les Mureaux, close to Paris. The facility to construct it is not far away from the Ariane 5’s vertical assembly building. In contrast to its predecessor rocket, Ariane 6 is assembled horizontally.
During the time of the visit, the factory already featured the fully assembled first stage for flight one. The Vulcain 2.1 engine was already integrated into the bottom of the rocket, and the transport container for the Canopée ship was prepared outside of the factory.
The factory also featured a hydrogen tank for flight three in testing, as well as parts for flight four and beyond. ArianeGroup confirmed to NASASpaceflight that six rockets are currently in work on the factory floor.
Down the line, the goal of the factory is to support twelve flights a year. This cadence is shared by the second stage facility and is dictated by the turnaround time of Canopée, which needs roughly 28 days for a full trip to the Guyana Space Center and back.
To date, Ariane 6 has roughly 30 launch contracts signed. These mostly consist of Amazon’s Project Kuiper, but also feature missions such as Galileo and the PLATO exoplanet telescope.
Ariane 6 features the Vulcain 2.1 hydrolox engine on its first stage, which produces 1,370 kN of thrust. It is the successor to the Vulcain 2.0, which was used on Ariane 5. Down the line, potential upgrades to Ariane 6, such as a change to the Prometheus methalox engine, are possible — although this is more likely on the future Ariane Next vehicle.
Prometheus is the “Precursor Reusable Oxygen Methane cost Effective propulsion System”, which is developed by ArianeGroup and ESA for Ariane Next. This methalox engine is part of a future engine development plan for ESA. It is also used on their Themis vertical takeoff and vertical landing prototype, in which ESA explores the idea of developing reusable rocket technology.
In the future, the Prometheus engine might be on the upgrade path for Ariane 6. Frank Huiban, Director of Civil Programs at ArianeGroup, said, “[When] working on space programs, you have to consider several things in parallel. You can not only work on your current development but also need to prepare the following one. This is what we do with Prometheus, Themis, and other projects we run together with ESA.
“The purpose is to prepare the key bricks for the next generation of European space transportation. Prometheus is part of that. It is not featured on Ariane 6 today, but it will be featured on other launch systems, developed by either ArianeGroup or other players. We will offer the engine to whoever will be interested to use it in systems.”
Regarding the fact that the first launch is a rideshare and the implications from that for the future of Ariane 6, he added, “For the inaugural flight, Ariane 6 will fly with more than 10 experiments and missions. It was a choice made together with ESA to invite all innovators to propose payloads for Ariane 6. From the very beginning, we start with this collective flight. In the future, we will have the possibility to group a large number of small missions to take the opportunity of one heavy lift to space.”
The second stage
For the second stage of Ariane 6, the company uses their facility in Bremen, Germany. The factory also features multiple stages in production, and the flight one stage already has its Vinci engine integrated. New for Ariane 6, compared to Ariane 5, is the ability to relight the engine for deep space missions.
Previously, Ariane 5 could only ignite its upper stage once, which allowed for missions to be sent to a geostationary transfer orbit (GTO). With this relight capability, Ariane 6 can now launch directly to geostationary orbit (GEO), using a relight a few hours into the mission. Overall, the current version of Ariane 6 can launch up to five metric tons to GEO.
“We already had the experience from the cryogenic upper stage of Ariane 5, but that stage was just a one-shot upper stage. You ignite it, you empty the tanks, it finishes, and that’s it. With Ariane 6, we wanted another feature. […] And this reignition of a cryogenic upper stage is the challenge we had to solve,” ArianeGroup told NSF.
The re-ignition of the stage is not done using chemicals but is instead driven by an electrical spark that ignites a mixture of hydrogen and oxygen gas, which then creates a flame and ignites the main chamber.
Aside from the addition of reignition, Arianespace also changed the material of the nozzle extension to a carbon ceramic.
Regarding the testing process, ArianeGroup said to NSF, “We are usually starting with electrical testing at the stages here, checking that the harness and connections are properly done. If that one is clean, we are going to a fluid test. This is where we pressurize the stage, check for leaks, and check the valve switching. We are verifying all the functions it has to perform in space.”
Another major change in the upper stage is the addition of the auxiliary power unit (APU). Its main role is to pressurize the tanks during flight and allow for longer coasting times. The device will also be used to deorbit or passivize the second stage after its primary mission. The system was tested at the DLR site in Lampoldshausen, Germany.
“We take guidelines very seriously to deorbit our stages, together with ESA, and this is why Ariane 6 fulfills these deorbit requirements, while other nations ignore the regulations,” Ariane told NSF.
Regarding the production of the Ariane 6 second stage, ArianeGroup added, “For this year, we are probably expecting two more stages, since we are just starting the ramp-up. The whole logistics chain is just starting. The team itself would be ready for more… We are limited by the production of the parts. We could produce more stages… If another ramp-up in the future is needed, we can support even more.”
The P120 rocket boosters are made by Avio in Italy. They are not only used for Ariane 6 but also for the VEGA-C/E. Ariane 6 comes with the ability to feature either two or four of the P120 boosters. The maiden flight will feature two, which is indicated by the “2” in “Ariane 62.”
Down the line, the plan is to upgrade the boosters to the P120C+. This will extend the length of the boosters, and feature 14 tonnes of additional propellant. The Amazon project Kuiper missions plan to utilize the upgraded booster after the second Kuiper flight.
Transport and the path to launch
With both stages now concluding their assembly and testing, the next step will be their shipment onboard Canopée. The hybrid ship, powered by both wind and fuel, was developed to transport the rocket. This approach was chosen to reduce the carbon emissions of the Ariane 6 project.
“With the ramp-up, the boat is designed to be always on rotation to support twelve flights a year.”
The ship will load both the first and second stages, as well as the booster casings for flights. Once it arrives at the Guiana Space Center in Kourou, the rocket will be fully assembled horizontally, before being moved to the launch pad.
After integration, Ariane 6 will not perform any more integrated testing, such as a static fire on the pad, as the qualification test from the certification pathfinder was deemed sufficient.
Regarding pre-flight tests, Tolker-Nielsen said, “We retired a huge amount of risks last year with the combined testing in Corou by performing tanking and firing tests. This went well. We also did important testing of the upper stage in Lampoldshausen, where we performed full flight simulations. We are very confident now, with shipping the flight hardware, and we are undertaking a qualification review. […] This will confirm that we can fly all of this safely.”
For the first flight, ESA will operate the launch as the primary contractor. For later flights, Arianespace will take over the operation of the vehicle. For flight one, Arianespace and CNES officials are still involved in the operation of the rocket.
Regarding this, Tolker-Nielsen said, “It has always been like that. It is a flight under ESA responsibility, we have bought this as part of our development program, so we are responsible for this first flight.”
The future of launching at ESA
Aside from Ariane 6, ESA’s Acting Director of Space Transportation Toni Tolker-Nielsen also talked with NSF about the future of launch vehicles at ESA.
NSF asked Tolker-Nielsen how his optimal European launch market looks in the future. “Tomorrow we will have Ariane 6 and Vega-C. That will ensure independent access to space from Europe. At the same time, we have all these micro launchers developed all over Europe. In France, in Germany, in Spain, in the UK. We would like to force them to grow and introduce more competition to Europe. We believe this is necessary for the competitiveness of the sector in the future.
Regarding the topic of reusability, he said, “For the launchers that will come after Ariane 6 and Vega-C, they will be reusable. That is because of two reasons: I believe the market, both institutional and commercial, will grow, which means we need an increased cadence. And with that, it becomes economically viable to have reusability. The other reason is sustainability. We can not throw away stages like that in the future. For these two reasons, I am convinced that the next generation will be reusable launchers.”
(Lead Image: The first stage for Ariane 6 flight model one in ArianeGroup’s integration hall in Les Mureaux. Credit: ArianeGroup)