After a day of suspense, NASA announced that it would attempt to launch its new mega-rocket to the Moon again on Saturday, following a failed first attempt on Monday due to a technical problem.
"We have agreed to change our take-off date for Saturday, September 3," said Mike Sarafin, in charge at NASA of the Artemis 1 mission, which should mark the start of the American program to return to the Moon.
The firing window begins at 2:17 p.m. local time (6:17 p.m. GMT) and runs for two hours.
A meteorological official warned that the probability of unfavorable conditions, such as precipitation or thunderstorms, was high at the moment, quantifying it at around 60%.
However, he said he was "optimistic" about the possibility of take-off, passing between the drops.
Progress point Thursday
Early Monday morning, thousands of people had gathered near the Kennedy Space Center in Florida, but were ultimately unable to experience the long-awaited takeoff of this rocket called SLS, the most powerful ever built by NASA.
The launch was canceled at the last moment due to a cooling problem in one of the four main engines under the rocket's main stage.
These RS-25 engines need to be cooled so they don't get shocked by the ultra-cold fuel when ignited.
But one of them could not reach the desired temperature.
This temperature is reached by letting a small part of the cryogenic fuel escape on the engines.
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NASA teams suspect a problem related to a possibly defective sensor, said John Honeycutt, in charge of the SLS program.
“The way the sensor behaves is not consistent with the physics of the situation,” he explained, adding that such a concern was not “really unusual”.
The teams therefore plan to collect enough data elsewhere, using other instruments, to ensure that the engine is properly cooled.
There are also plans to start engine cooling earlier in the countdown.
A leak problem when filling the fuel tanks had also been observed on Monday, and even if it had been overcome, NASA teams will conduct an inspection by Saturday.
A new meeting will be organized on Thursday to take stock.
Test mission
The Artemis 1 mission is to launch the unmanned Orion capsule 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 .
After 42 days in space, the main objective is to test the capsule's heat shield during its return to the Earth's atmosphere, at nearly 40,000 km/h and a temperature half as hot as the surface of the Sun.
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Only mannequins will take place on board, equipped with sensors recording vibrations and radiation levels.
The capsule will venture up to 64,000 km behind the Moon, farther than any other habitable spacecraft so far.
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.
The goal is to establish a lasting human presence on the Moon, in order to learn how to live in deep space, and to test all the technologies necessary for a round trip to Mars.
