Behind-the-scenes report on Ariane 6

June 23, 2022 to Guiana Space Center. Ariane 5 took off the day before. He has only four flights left to make, the next of which – September 6 – while the last will send the European Juice probe to the icy moons of Jupiter in April 2023.

It is precisely in 2023 thatAriadne 6 must now fly when it was originally scheduled to take off in 2020. The Covid-19 has, in large part, delayed the first flight but in reality, a launcher never takes off on time for his first time. For Ariane 6, there remains a final stretch. ” It is a campaign long coursewith strong moments, but it’s an endurance race says Franck Huiban, Civil Programs Manager at ArianeGroup.

Spotlight on “system” tests

Ariane 6 has already begun its encounter with its launch pad. More precisely, it is the very first copy of the central body of Ariane 6 which has joined “the gantry », where were joined full-size models of the four boosters side panels that equip the rocket European. Already, before the arrival of the central body, the launch pad had been tested with a “skeleton” model.

Long awaited, the combined trials are underway. They consist in testing in real conditions the equipment of the launcher but also of the launch pad. To conclude, a real Ariane 6 was needed on site. The fact that boosters P120C are only models for the moment is not important, their fuel being above all solid, Conversely of the central body. Moreover, the P120C has already been qualified because it is also the first stage of the new Vega-C rocket, whose inaugural firing on July 13 was a success. The central body used will not take off either. It is used for testing and it is a second copy, not yet arrived at the Guiana Space Center, which will carry out the maiden flight of Ariane 6 in 2023.

During the combined tests, several updates fire are planned, including one that will last as long as a real flight but with the rocket remaining on the ground, as well as filling tests and drainage reservoirs. The aim is to test the suitability of the launcher and the launch pad for take-off conditions, but also to develop all the procedures that will be followed during the launch. As far as propulsion itself is concerned, Franck Huiban, Civil Programs Manager at ArianeGroup reminds us that “ the propulsion of Ariane 6 is qualified, the Vulcain [moteur 1^er étage, ndlr]the Vinci [moteur étage supérieur]and the APU [Auxilliary Power Unit]this small additional engine that we included in the upper stage and which considerably extended the launch capabilities of Ariane 6, and of course the P120C “.

” We are really at the last steps”says Tony Back Santos, Deputy Head of Combined Testing at theESA, or in the final stages. In reality, the combined test campaign had already started several months before our arrival at the end of June. Until the arrival of the central body, the tests concerned in particular “the upper part”, with qualification of cryogenic arms connecting the launch pad to the launcher to supply the central body with fuel until the last second. Today, there remains above all the firings and all the possible and imaginable checks before moving on to Ariane 6 qualification.

Soon a date of the inaugural firing?

It should be noted that the combined tests testing the main stage at the Guiana Space Center (CSG) are doubled by other “system” tests of the upper stage in Lampoldhausen, Germany, also with firings. Once these two campaigns have been concluded, we can “qualify” Ariane 6 and its launch pad, then move on to the first flight campaign. In other words, until this qualification has been completed, it is difficult to say precisely when Ariane 6 will take off for the first time. However, Joseph Aschbacher, DG of ESA, specified that the calendar will be clearer next October.

At CSG, Ariane 6 is installed everywhere. At the Ariane/Vega control center, the new control room is already operational and undergoing testing. At the launch site, the Launcher Assembly Building (BAL) has successfully integrated its first Ariane 6 central body. The one that will make the inaugural flight has not yet been assembled or even arrived. On June 23, Franck Huiban told us that the two floors of the first flying example were being integrated in Bremen and Les Mureaux.

Already, teams working on Ariadne 5 were deployed on Ariane 6. The schedule is now tight for Ariane 6. After a few institutional flights to run in the campaign procedures, the “ ramp up » (the ramp-up) will follow with 18 flights for Amazon from 2024 to 2026. We think less and less that Ariane 5 and 6 shots could mix for a few months. Ariane 5 is gradually disappearing, and with it a whole world of the space industry, giving way to the arrival of new, more simplified, optimized and thus less expensive methods.

Fly cheaper at CSG

Launch Group 4 (ELA 4) is a next-generation launch pad compared to all the others at CSG. It is the Cnes which has the project management. ELA 4 is actually 9^e launch set built at CSG. ELA 4 demonstrates many innovations that will serve to reduce costs. Mirtho Madlon, ELA 4 deputy manager at Cnes, welcomes us to the launch pad and explains why it was built there, namely first of all ” be able to have a granite base large enough to support the entire infrastructure “. It is true that the quality of the soil on the Guiana coast may require fairly deep foundations before reaching a solid layer. Finally, safety: Cnes is responsible for backup goods and people. The site is quite far from other launch pads, and also from habitable areas. Here, we are about twenty kilometers from Kourou “.

Mirtho Madlon tells us how operating costs are reduced. First of all, fewer buildings to air-condition and maintain: only one for Ariane 6 (the BAL) compared to two for Ariane. The horizontal assembly at the BAL makes it possible to use a lower building, and therefore less expensive. For information: the air conditioner (essential for the health of the satellites) represents 10% of the electricity consumption of the CSG, which represents 10% of all consumption in French Guiana!

Mirtho Madlon also specifies that there is only one launch table, fixed on the launch pad, against two tables mobiles maintenance to carry Ariane 5. The “deluge” system (very strong water fountains debit) used during firing protects the launch pad installations during take-off. The goal for Cnes is for ELA 4 to be operational again after five days, a rate that can only be found at SpaceX. Another innovation: the cryogenic arms, which provide the connection between Ariane 6 and ELA 4 (in particular the fuel supply), are removed “in positive time”, i.e. after the main engine has been fired, at the time of takeoff. Thus, in case ofabortion during the firing (which sometimes happens), we do not have to reconnect the launcher to the launch pad, requiring a postponement of the flight to the next day.

The portico, the “Guyanese Iron Lady”

It is understandable that much of the success is based on the mobile gantry, responsible for vertically erecting Ariane 6 to join the P120Cs on the launch pad and make the final preparations. The gantry moved back 140 meters before takeoff. It is a veritable metal cathedral that moves on rails using 128 electric motors. It must be said that the gantry weighs nearly 8,000 tons, which is “roughly the weight of the Eiffel Tower”.

“When you move the Ariane 6 gantry, it amounts to moving the Eiffel Tower”says Franck Huiban, Civil Programs Manager at ArianeGroup.

Innovations in the face of costs, the design of Ariane 6 responds directly to the lower costs proposed by SpaceX. Tony Dos Santos, Deputy Head of Combined Testing at ESA, said: ” with Ariane 5, we were in the 1990s, we weren’t talking about costs, it was technology above all. We had a very technological launcher. Ariane 6 inherits from Ariane 5, but with cost reduction as a key word “. To which Franck Huiban of ArianGroup responds immediately: ” Ariane 6 is a launcher that embeds a lot of technological innovations compared to Ariane 5 “.

An overflowing manifesto

Horizontal assembly and rolling, more economical infrastructure in terms of energyshorter firing campaigns for a better rate, ESA wants the ELA 4 launch pad to be able to sustain the same rate as a launch pad Falcon 9 : two shots per month. This rate will significantly reduce the price of a flight. The other advantage of Ariane 6 is its flexibility. Version 64 (with four boosters) achieves the same capacities as Ariane 5, while version 62 (two boosters) could replace the Soyuz and serve theorbit low. Franck Huiban specifies that the APU ” will allow the upper floor to fulfill very complex missions, [avec] sophisticated trajectories that are perfectly adapted to the deployment of constellation of satellites “.

A more efficient version with more powerful boosters P120C+ should see the light of day in a few years, and could be used with lunar ambitions. There is also the question of adapting Ariane 6 to manned flight. At ArianeGroup, we are assured that there would be no radical changes to be made to the rocket to accommodate a European spacecraft. As for the question of when, Daniel Neuschwander, in charge of space transport systems at ESA, assures us that it is above all a political question. Meet at Space Summit of 2023.

The order book is filled to the brim! With the mega-deal with Amazon and the war in Ukraine which deprives Arianespace of the Soyuzmany satellites are on board Ariane 6. With a first flight in 2023, we can hope for a ramp-up (ramp up) in 2024 at the earliest, and the 18 flights for Amazon must be completed by 2026 inclusive. As it jostles in the Ariane 6 manifesto, the ESA is considering to use SpaceX for sending certain agency payloads.