Long-delayed Ariane 6 rocket is 'ready to go' – hopefully – says European Space Agency

The European Space Agency (ESA) has declared its Ariane 6 rocket is "ready to go” – at least in terms of its ability to launch the long - delayed rocket. But some concerns remain about the performance of its upper stage.

That mixed news came in a Tuesday post that detailed two recent tests of the rocket.

A December 7 test of the rocket's upper stage assumed a normal liftoff, but then introduced what the ESA described as "degraded conditions to assess the robustness of the stage and how it would behave in extreme and unexpected conditions."

The test was aborted after sensors detected that some parameters had gone beyond predetermined thresholds. Engines were shut down and the upper stage test model placed in a safe condition.

This was not the result the ESA wanted. But it also wasn't disastrous, because the test didn't use a normal Ariane 6 flight profile or the configuration it will use on its first flight. Results of an investigation are due in January 2024, but the ESA stated it is "confident that these investigations will not impact the schedule to Ariane 6 inaugural flight."

A test staged on December 15 went rather better.

This "combined test loading" effort "tested a launch countdown aimed to qualify the launch system in degraded conditions to ensure its robustness and prepare for operations."

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A launch sequence was run, complete with countdown simulated launch that included removal of the mobile gantry, plus filling and draining of the launcher's upper and core stage tanks with liquid hydrogen (at -253°C) and liquid oxygen (at a slightly less chilled -183°C).

"The rehearsal was very well executed, and the countdown ran exactly as planned," ESA's statement reads, describing the test as "a full success."

And then came the welcome news that "The launch operations for Ariane 6 are mastered, we are ready to go."

The ESA currently lacks a heavy launch capability since the last Ariane 5 flew in July 2023. Ariane 6 is running around four years late, but it's hoped it will launch in 2024.

If the project meets that target, it will still leave the ESA way behind commercial launch rivals like SpaceX, given Ariane 6 is not reusable and doesn't greatly exceed the Musky space concern's possible payloads. ®