Launch

Ariane 6: Europe Succeeds in its Return to Space

Published on 10 July 2024

First successful mission for the new European Ariane 6 launcher. After take-off, the separation of the boosters and the fairing, the upper stage turned on its Vinci engine several times. The nanosats were released. The two capsules, however, could not be released.

It was the most anticipated flight of the year. The inaugural flight of Ariane 6, to enable its certification for future commercial flights. It must be said that the order book of the new European launcher is already well filled. After a well-executed take-off, Ariane 6 successfully passed all the stages of this launch until the release of the nine nanosatellites that made up most of the payload. This was the main objective of the mission. However, a failure during the re-ignition of the APU, the attitude propeller, caused the upper stage to deflect. This anomaly made it impossible to start the Vinci engine a third time, nor to place the upper stage in a good position to allow its re-entry into the atmosphere and the release of the two demonstration capsules. A slight downside that does not call into question the success of the take-off.

Des préparatifs réussis

Décollage nominal

Gallerie photo : Le plan de vol à la seconde près

En vidéo ; Revivez le lancement d'Ariane 6

L’APU imprévu

Réactions : L’Europe est de retour dans l’espace

The mobile gantry began to withdraw at dawn in Kourou.

SUCCESSFUL PREPARATIONS

THE LAUNCH SEQUENCE BEGAN WELL BEFORE THE FINAL COUNTDOWN

Particularly favourable weather allowed Kourou to activate the mobile portal withdrawal at dawn. This 8200-tonne and 89m high metal monster mounted on rails took several minutes to travel the 140 m allowing it to release Ariane 6. This portal serves both as a vertical final assembly building for the central body, boosters and fairing. It is also used to protect the launcher up to a few hours from take-off.

Filling Up Four Hours Earlier

Then, four hours before the launch, the filling of the tanks began. A total of 180 tonnes of liquid oxygen at -180° and hydrogen at -253° was loaded into the four tanks. Ariane 6 has two in the lower stage to power the Vulcan 2.1 engine and two smaller tanks in the upper stage, to power the Vinci engine. Finally, five minutes before the launch, the synchronised sequence began. This is a fully automated sequence of operations until take-off.

Nominal Take-off

At 9 p.m., Ariane 6 Left the Launchpad With No Problems

The take-off was to take place at 8 p.m. It was finally postponed to 9 p.m. due to a minor malfunction of data acquisition systems. The problem was quickly identified and resolved, but led to this slight postponement. From zero hour, only seven seconds after the Vulcan 2.1 engine, the cryogenic arms moved away and the P120C boosters turned on to provide most of Ariane 6’s thrust. The launcher took off, provoking an enthusiastic reaction from the 4,000 people gathered at Cité de l’espace in front of a giant screen. After 2 minutes 15 seconds of flight, the boosters separated. A stage that we followed thanks to the on-board cameras on the rocket. A minute later, it was the fairings that opened, revealing the payload. Then 8 minutes after take-off, the Vulcan engine turned off, the upper stage separated and the Vinci engine turned on and then turned off after 18 minutes of flight.

The Re-ignition of the Vinci Engine and the Deployment of Payload

But would it fire up again? The success of the mission depended on it. After 56 minutes, the ignition control worked perfectly. Then, a few minutes later, the four deployers were able to release the nine Cubesats, validating the mission’s success.

At 9 p.m., seven seconds after the Vulcan engine was turned on, the P120C boosters ignited and Ariane 6 took off.

The flight plan to the nearest second

We were able to follow the main stages of the flight plan thanks to cameras installed on the upper floor of Ariane 6 that gave us incredible images.

The Unexpected APU

The last demonstration phase could not be carried out due to a failure of these attitude thrusters

After the release of the CubeSats, a demonstration phase began. It was a question of turning the APU back on, the propeller that corrects the attitude of the upper stage. This APU is another innovation of Ariane 6 that allows it to manoeuvre more easily between different levels of the orbit. “It was a question of understanding how the upper stage behaved in microgravity,” said Martin Sion of ArianeGroup. “At one point, we turned the APU back on, it fired again, then stopped. And we don’t know why. We will study it when we have all the data.” The Vinci engine that was to perform a third boost was then no longer in good condition for re-ignition. The stage had to be positioned in such a way as to make a re-entry to the atmosphere and release two capsules that had to finish their journey in the Pacific Ocean to test their heat shields.

At the top right of this telemetry image, we can see that the trajectory of the upper stage is very slightly below what was planned, which did not allow the capsules to be released.

The Unexpected APU

The last demonstration phase could not be carried out due to a failure of these attitude thrusters

After the release of the CubeSats, a demonstration phase began. It was a question of turning the APU back on, the propeller that corrects the attitude of the upper stage. This APU is another innovation of Ariane 6 that allows it to manoeuvre more easily between different levels of the orbit. “It was a question of understanding how the upper stage behaved in microgravity,” said Martin Sion of ArianeGroup. “At one point, we turned the APU back on, it fired again, then stopped. And we don’t know why. We will study it when we have all the data.” The Vinci engine that was to perform a third boost was then no longer in good condition for re-ignition. The stage had to be positioned in such a way as to make a re-entry to the atmosphere and release two capsules

Passivation of the upper floor

Not being in position to return to Earth, these capsules risked becoming additional debris. The upper stage was therefore passivated so as not to create a danger for the satellites it could encounter. “We have one event, but everything else on the mission has followed the plan to the letter. So it’s a shame, but it’s also the reason why we do flight demonstrations because it’s something that we can’t do on the ground,” concluded Martin Sion. A dysfunction which in no way undermines the immense success of this mission in the opinion of all those responsible for Ariane 6.

Europe is Back in Space

The Relief and Pride of European Space Directors was Plain to See

“This is a historic moment. The inaugural flight of a heavy launcher does not happen every year. Today, we successfully launched Ariane 6 and it is a great step forward,” reacted Josef Aschbacher, the Director General of ESA, at a press conference. “So Europe is back“. It must be said that the success of this launch was not guaranteed. “Before take-off, when I was asked “How do you feel?”, I replied that I was 96% confident and 4% very stressed,” said Tony Tolker Nielsen, the current director of space transport at ESA. “But I think I was lying a little. Now, all this stress has turned into emotion and we are very, very happy.” The chair of CNES, Philippe Baptiste, congratulated all the teams who worked hard to enable this take-off. “This is a very important day because we are talking about Europe’s sovereignty, European access to space. You are not a space actor if you do not have access to space, so it is a great success.” For Caroline Arnoux, the director of the Ariane 6 program at Arianespace, this moment was also eagerly awaited by customers who trust Ariane. “Thanks to this success, we will be able to serve them. We have many customers who were waiting for Ariane 6 and now Ariane 6 is here, “she said delightedly. Moreover, Stéphane Israël, the CEO of Arianespace, is already focussed on the next launch that should make it possible to launch the military observation satellite CSO-3. “What was realised tonight allows us to prepare full speed for the next launch. We have a goal that motivates us, which is to make a second launch by the end of the year.“

At a press conference, officials from ESA, CNES, ArianeGroup and Arianespace expressed their relief after this successful launch.

EumetSat’s “surprising decision”

The press conference was also an opportunity to return to the withdrawal of EumetSat, which chose, on June 27, contrary to what was planned, that its next MTG-S1 satellite would no longer leave on the European launcher, but on a SpaceX Falcon 9 rocket. A decision described as “surprising” by Josef Aschbacher on X (ex-Twitter). “The first 18 minutes of the launch of Ariane 6 would have been enough to launch a satellite like those of EumetSat,” said Stephane Israel, for whom this first phase of the launch was similar to a launch of Ariane 5. “When you see all the efforts that have been made by Member States to have independent access to space, the efforts made at the industrial level to make this programme what it is today, it would make sense for institutional payloads in Europe to be launched by European launchers when they are available,” said Martin Sion, the executive head of ArianeGroup, expressing his surprise. “And now, Ariane 6 is available“.