Fifty years after the last Apollo flight, the Artemis 1 mission should mark the launch of the American program to return to the Moon, which should allow humanity to then reach Mars, aboard the same vessel.

The Orion capsule, tested here without a crew, will be rocketed into orbit around the Moon, to verify that the vehicle is safe for future astronauts — including the first woman and first person of color to walk on the lunar surface .

“This mission carries the dreams and hopes of many people,” said NASA boss Bill Nelson. “We are now the Artemis generation.”

Take-off should take place at 8:33 a.m. (12:33 p.m. GMT, 2:33 p.m. in France) from launch pad 39B at the Kennedy Space Center.

The weather is 80% favorable for an on-time launch, at the start of the two-hour launch window. From its height of 98 meters, the orange and white SLS rocket will not be able to take off in the event of rain or thunderstorms.

Its tanks must be filled overnight from Sunday to Monday with more than three million liters of fuel — liquid hydrogen and oxygen.

Sign of the times, the first female launch director at NASA, Charlie Blackwell-Thompson, will give the final green light. Women represent 30% of the workforce in the launch room – compared to only one at the time of Apollo 11.

Two minutes after takeoff, the boosters will fall back into the Atlantic. After eight minutes, the main stage will detach in turn. Then, after about an hour and a half, a final push from the upper stage will put the capsule on its way to the Moon, which it will take several days to reach.

Between 100,000 and 200,000 people are expected to attend the show, including the Vice President of the United States Kamala Harris.

– Distance record –

In addition to the weather, technical problems could lead to the postponement of takeoff until the last moment, warned NASA officials, who insist that it is a test flight.

The next possible take-off date is September 2.

The main objective of the mission is to test the heat shield of the capsule, which will return to the Earth’s atmosphere at nearly 40,000 km / h, and a temperature half as hot as the surface of the Sun.

Instead of astronauts, mannequins took place on board, equipped with sensors recording vibrations and radiation levels. Microsatellites will also be deployed to study the Moon, or even an asteroid.

On-board cameras will make it possible to follow this journey of 42 days in total.

The capsule will venture up to 64,000 km behind the Moon, farther than any other habitable spacecraft so far.

A complete failure of the mission would be devastating for a rocket with a huge budget (4.1 billion per launch, according to a public audit) and several years late (ordered in 2010 by the American Congress for an initial date of takeoff in 2017) .

– Living on the Moon –

“What we begin with this liftoff on Monday is not a short-term sprint but a long-term marathon, to bring the solar system, and beyond, back into our sphere,” Bhavya Lal, associate administrator, said confidently. at NASA.

After this first mission, Artémis 2 will carry astronauts to the Moon in 2024, without landing there. An honor reserved for the crew of Artemis 3, in 2025 at the earliest. NASA then wants to launch about one mission per year.

The goal: to establish a lasting human presence on the Moon, with the construction of a space station in orbit around it (Gateway), and a base on the surface.

There, humanity must learn to live in deep space and test all the technologies necessary for a round trip to Mars.

A multi-year journey that could take place “at the end of the 2030s”, according to Bill Nelson.

But before that, going to the Moon is also strategic, faced with the ambitions of competing nations, notably China.

“We want to go to the south pole (of the Moon, editor’s note), where the resources are”, in particular water in the form of ice, detailed Mr. Nelson on NBC. “We don’t want China to go there and say this is our territory.”