Time is running out for NASA.

After two failed tests this summer, the American space agency was again trying to launch its mega-rocket towards the Moon on Wednesday, November 16, hoping to make up for the delay accumulated during the last hours of the countdown due to a fuel leak. , eventually fixed.

The first flight of the SLS rocket, the most powerful in the world, is scheduled for Wednesday from Florida at 1:04 a.m. local time (06:04 GMT), with a possible launch window of two hours.

The weather at Kennedy Space Center was cooperative, with conditions 90% favorable.

But as in previous attempts, the operations of filling the rocket with its cryogenic fuel - more than 2.7 million liters of liquid hydrogen and oxygen - gave NASA a hard time.

After several hours of filling without a hitch, an ultra-flammable hydrogen leak was detected at the foot of the rocket.

A team of technicians had to be sent to the launch pad to carry out repairs, which took about an hour.

The leak did not reappear when filling resumed.

The take-off time has for the moment been maintained.

"Lots of sweat and tears"

Fifty years after the last Apollo mission, the Artemis 1 mission, which will circumnavigate the Moon without landing there and without an astronaut on board, should make it possible to confirm that the vehicle is safe for a future crew.

It should mark the great beginning of the Artemis program, which notably plans to send the first woman and the first person of color to the Moon.

The goal is to establish a lasting human presence there, in preparation for a trip to Mars.

"A lot of sweat and tears went into that rocket ship," NASA chief Bill Nelson said on Tuesday.

"It will keep us going back and forth to the Moon and beyond for decades to come."

>> Mission Artemis 1: "We train on the Moon to go to Mars"

Despite a night launch on Wednesday, some 100,000 people are expected to admire the show, especially from the surrounding beaches.

"I was too small for the Apollo missions so I wanted to come and see the next moon lift, in person," Andrew Trombley, 49, told AFP on Cocoa Beach.

Many astronauts also made the trip to the Kennedy Space Center, including Frenchman Thomas Pesquet.

This summer, the first take-off attempt was canceled at the last moment due to a faulty sensor, and the second due to a hydrogen leak.

After these technical problems, two hurricanes - Ian then Nicole - successively threatened the rocket, postponing take-off by several weeks.

Years of delay at a cost of billions of dollars

In total, the program is years behind schedule and the success of this mission, which costs several billion dollars, has become imperative for NASA.

Right after takeoff, crews from the control center in Houston, Texas, will take over.

After two minutes, the two white boosters will fall back into the Atlantic.

After eight minutes, the main stage will detach in turn.

Then, about an hour and a half after takeoff, a final push from the upper stage will put the Orion capsule on its way to the Moon, which it will reach in a few days.

There, it will be placed in a distant orbit for about a week, and will venture up to 64,000 km behind the Moon - a record for a habitable capsule.

Finally, Orion will begin its return to Earth, testing its heat shield, the largest ever built.

It will have to withstand a temperature half as hot as the surface of the Sun as it passes through the atmosphere.

If the takeoff takes place on Wednesday, the mission should last 25 and a half days, with a landing in the Pacific Ocean on December 11.

After the Saturn V rocket of the Apollo missions, then the space shuttles, SLS must bring NASA into a new era of human exploration: this time deep space.

In 2024, Artémis 2 must take astronauts to the Moon, still without landing there.

An honor reserved for the crew of Artemis 3, in 2025 at the earliest.

NASA then plans one mission per year, to build a space station in orbit around the Moon, and a base on its south pole.

The goal is to test new equipment there: suits, vehicle, mini-power plant, use of ice water on site... All in order to establish a lasting human presence there.

This experiment should prepare a manned flight to Mars, perhaps at the end of the 2030s. This trip, of a completely different scale, would take at least two years round trip.

>> To read also: "France joins forces with NASA's program to explore the Moon"

With AFP

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