No special launch, protective cocoon, delay… Six things to know about the Ariane 6 rocket before its takeoff

Franceinfo presents the new flagship European launcher on the occasion of its inaugural flight on Tuesday.

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A replica of the Ariane 6 rocket is placed in the mobile gantry dedicated to the launcher, at the Kourou spaceport (French Guiana), on April 12, 2023. (ERIC LALMAND / BELGA PHOTO / MAXPPP)

It’s the big day! The Ariane 6 rocket is (finally) scheduled to make its maiden flight on Tuesday, July 9, a little over a year after the final flight of Ariane 5. Franceinfo presents the new European heavy launcher, which stands at 62 meters high, a little higher than the first floor of the Eiffel Tower.

1It exists in two versions

Modular, Ariane 6 offers two versions. The one called “Ariane 62” (or A62) has two boosters, that is to say two propulsion blocks. The version called “Ariane 64” (A64) has four. The first version weighs 530 tons and develops a thrust of 800 tons at takeoff. The second weighs 860 tons and develops 1,500 tons of thrust at takeoff.

Illustration of an Ariane 6 rocket version 62, with two boosters (left) and a version 64, with four boosters (right). (D. DUCROS / ESA)

    2 Launches up to half the price of Ariane 5

    The two versions of Ariane 6 allow it to better adapt to orders, with greater flexibility. And the elements they have in common lead to a reduction in the cost of launches, up to halving the prices compared to those of Ariane 5.

    “Ariane 5, which was an excellent launcher, was quite expensive”recalled Philippe Baptiste, president of the National Center for Space Studies (CNES), on BFM Business at the beginning of June. “Today, new launchers must be efficient, that is to say effective and light, but also as cheap and modular as possible”also explained Marie Jacquesson, head of the CNES space transportation systems department, in an article for The Conversation published in 2022. It is in this same logic of cost reduction that the European medium-sized launcher Vega-C and Ariane 6 operate with the same solid propellant booster, their fuel. “There is a real market expectation to have access to Ariane 6assured Philippe Baptiste to the Association of Professional Journalists of Aeronautics and Space. If only to have an alternative to SpaceX.”

    3 It launches satellites at different altitudes

    The last stage of Ariane 6 is equipped with an engine that can be reignited, which allows it to drop satellites at different altitudes (because not all of them then travel at the same height). In this sense, Ariane 6 is adapted to the current space launch market, largely occupied by telecommunications and more recently by satellite constellations, such as Starlink, SpaceX, or Kuiper, for Amazon.

    Satellite constellations allow users on the ground to access the internet in very remote areas, where there is no infrastructure, network (3G, 4G and 5G), cable or fiber. While in Western Europe, where the network is very dense, satellite constellations are not always of primary use, they can, however, prove invaluable in Central Asia, in the African or South American deserts.

    4She arrives four years late

    “The first Ariane 6 rocket will fly on July 16, 2020”, declared on franceinfo the executive chairman of Arianespace, Stéphane Israël, on June 23, 2017. In the meantime, the Covid-19 pandemic caused several delays. With the lockdowns, construction sites were shut down, particularly at the Kourou spaceport in Guyana. The resumption was gradual, with a strict health protocol and isolation in the event of symptoms and positive tests.

    The Ariane 6 teams also faced various design problems, pushing back the date of the inaugural flight over the months until summer 2024. For example, an engine ignition test scheduled for October 2023 did not take place until November due to an anomaly in a hydraulic circuit.

    Longer-than-expected tests of the arm system that fills the launcher and auxiliary engine with cryogenic fuel also caused delays, the report said. Le Figaro in 2022. “Each arm weighs 20 tons and we demand the micrometric precision of a Swiss clock.”summarized Marie Jasinski, project manager on Ariane 6 between 2014 and 2019, in this CNES presentation video. The tests of software exchanges between Ariane 6 and the new launch base have also been extended, the newspaper reports.

    5A new dedicated firing point in Kourou

    At the Kourou spaceport, a special launch pad was built for Ariane 6, which is not the case for all launchers. Its name: ELA4, for “Ariane launch set number 4”. The work, entrusted to CNES by the European Space Agency, was colossal, requiring a year of earthworks. The firing range covers 170 hectares and is consists of a launcher assembly building, a launch zone, a road connecting the different buildings and logistics and storage areas.

    View of the Ariane 6 launch pad under construction, in Kourou (French Guiana), on July 11, 2022. (ESA-CNES-ARIANESPACE / OPTIQUE VIDEO DU CSG)

    From space, the various facilities of the spaceport are clearly visible and the area reserved for Ariane 6 seems larger than those dedicated to other launchers.

    The various facilities of the Kourou spaceport (French Guiana), seen from the International Space Station. (ESA / NASA)

    6It benefits from a rolling protective cocoon

    It’s impossible to miss. On the Ariane 6 launch pad stands a huge building. It’s a gantry that protects Ariane 6 from the elements until takeoff. Its dimensions: 89 meters high and 49 meters wide. The upper doors are 42 meters high, the lower ones are 30. The whole thing, which weighs 8,200 tonnes, moves on rails at a speed of 7 metres per minute. Before launch, the gantry must move away from the launcher, placing itself 120 metres away from it. It is the largest mobile building in the world, according to CNES.

    The cocoon is not an empty shell. The interior is a maze that has 48 platforms, presents CNES, allowing teams to assemble the boosters, integrate the upper part where the satellites are housed, supply the launcher with fuel and monitor all the parameters of the rocket before takeoff. This innovative system is specific to Ariane 6 and differs from that of Ariane 5. Before its launch, Ariane 5 went through a “final assembly building”, then performed a “rolling” (at a speed of 4 km/h) to reach its launch table.


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