There were also issues reported with the flight termination system and the launch abort system – two safety systems that protect astronauts and the public.
The flight termination system allows engineers on the ground to destroy the rocket if it veers off course. It reportedly had a communications issue, which was resolved by using hardware from the previous Space Shuttle programme.
The launch abort system is Orion’s emergency escape tower, designed to pull the crew capsule away from the rocket in the event of an emergency during launch or ascent. It reportedly gave a higher-than-expected temperature reading, but it was judged that it wouldn’t affect the launch.
With these issues resolved, the countdown clock was held at 10 minutes while engineers went through final preparations.
We then heard the staccato rhythm of the calls by each engineer responsible for the rocket’s critical systems.
One by one the voices came back: “Booster, go”, “GNC, go”, “Range, go” – each reply, a tiny release of tension and a build-up of expectation.
“Artemis II, this is Launch Director – you are go for launch,” the crew was told. “We go for all humanity,” Commander Reid Wiseman responded.
The rocket then launched into the sky, to the awe of those watching at the Kennedy Space Centre and around the world.