Artemis I: what are the next steps for the mission to the Moon?

It’s the great return to the Moon! Initiated in 2019 by former US Vice-President Mike Pence, NASA’s Artemis program aims to bring astronauts back there, as during the Apollo missions, more than 50 years ago. Artemis, however, is more ambitious. The goal is to use lunar missions to prepare for manned flight to Mars. Before all this, we must test the new means of navigation: the Orion spacecraft and the SLS lunar rocket. It is the Artemis I mission which began on Wednesday, November 16. Here is its unfolding.

Article originally published in March 2022. Updated on November 17, 2022, after the successful launch of Artemis I.

March 2022 was the first time the launcherlauncher SLS (Space Launch System) showed himself completely to the public of Cape CanaveralCape Canaveral. Accompanied by the Full moonFull moon, the SLS dominates the historic launch site as it slowly makes its way to launch pad 39B. It reminds observers and an entire generation of the path the Saturn V traveled to that same launch pad before sending astronauts to the MoonMoon. This is a key step for NASA which has succeeded taxiing of the SLS lunar rocket. What next?

Relive the take-off of the SLS recorded live on November 16. © Futura

The SLS has arrived on its launch pad, now what?

It was necessary to check that the SLS adapts well to its launch pad. NASA had planned a dress rehearsal in early April. It finally took place on June 20 and notably included the SLS tank filling test. To take off, the rocketrocket Lunar will consumeoxygenoxygen and of thehydrogenhydrogen in the state liquidliquid. If the tanks have already been pre-tested up to the explosion, then this is to check that everything works well under the conditions of the launch countdown.

Once the dress rehearsal was over (and not quite complete), NASA communicated a first takeoff date of August 29 as expected. There’s no one aboard the spaceship OrionOrion which was laid atop this titanic launcher. Artemis I is a qualification mission, both for the spacecraft manufactured in Europe and the United States, and also for the SLS produced by Boeing. If the mission is successful, the astronauts of Artemis II will take over.

” We are ready ! »

Kennedy Space Center Launch Pad 39B experienced Apollo 10, the US Space Shuttle, the launch of the space stationspace station Skylab, or the Apollo-Soyuz peacekeeping mission. It has been renovated and reinforced to be able to support a weight equivalent to 2,125 African elephants! It is robust enough to accommodate the 2,628 tons of the SLS lunar rocket. The latter will only play a role in the mission for one hour and fifty-three minutes. The rest of the mission concerns the Orion ship and will last nearly 25 days.

Take-off has been postponed several times since August 29. In question, concerns of hydrogen leakage, a sensorsensor defaulting, and the threat of a hurricanehurricane. Finally, the long-awaited take-off took place on November 16.

At T-0, the launch begins with the update firefire four RS-25 motors as well as two gigantic thrustersthrusters solid fuel boosters supplied by Northrop Grumman. They are ejected two minutes later, completely emptied of their fuel. The RS-25 engines continue to roar for another six minutes and fourteen seconds. At this point, the main stage of the SLS, recognizable by its colorcolor red, has finished its work and we are already more than 150 kilometers above sea level, therefore in space.

Two minutes after the main stage release, the Orion ship deploys its solar panels. It will have already been stripped of its protective panels as well as the rescue tower, this essential device for ejecting the vessel and its occupants in the event that the rocket catches fire on the launch pad or while crossing theatmosphereatmosphere.

It was not until much later, 54 minutes after the start of the launch, that the propulsion of the second stage, the ICPS, supplied by the United launch Alliance (ULA). The ICPS is used a first time to gain altitude and a second time half an hour later to inject the Orion spacecraft into a transfer orbit towards the Moon. Once its mission is complete, the ICPS is dropped. We then take the opportunity to eject a dozen CubeSatsCubeSats who are secondary passengers on this flight.

Around the Moon

This is not the Orion’s first demonstration flight. It has already made a first flight in 2014, as part of the program ConstellationConstellation, precursor of the Artemis program. This flight will allow him to test once again the manned module, manufactured by Lockheed Martin, as well as the service module provided by the European Space Agency (ESAESA). The trajectory that Orion will achieve during the Artemis I mission is equivalent to that of the mission ApolloApollo 8.

It will take a little over three days to reach the Moon. To fit into orbit, Orion will pass nearly 100 kilometers from the surface and will use the gravitygravity lunar to increase its speedspeed. With the help of a few corrections, the spacecraft will then go into a retrograde orbit around the Moon at an altitude of almost 70,000 km. Indeed, the spacecraft will revolve around the Moon in the opposite direction to its revolution around the Earth. It will remain there for several days in orbit.

NASA will take the opportunity to recover data, test the various communication and navigation systems of the ship. To communicate with Orion, NASA will use the Deep Space Networkantenna array used to interact with interplanetary probes.

The ship will house an experiment (Mare) whose purpose is to measure the level of radiation to which the occupants of the ship could be exposed. Around the Moon, we are almost no longer protected by the earth’s magnetic fieldearth’s magnetic field which deflects the particles ejected by the SunSun. Aboard the ship, three mannequins will be covered in sensors, and one of them will wear an experimental vest that is supposed to block out some of the radiation.

Return to Earth and continuation of the program

To leave lunar orbit and return to Earth, Orion will once again pass nearly 100 kilometers in altitude to accelerate, not only using lunar gravity to do so but also using the main engine of the service module. It will then place itself in a transfer orbit in the direction of our Planet. The trip should last a little over three days.

It is after a three-week journey covering more than 1.3 million kilometers that the Orion spacecraft will return to Earth. Before entering the Earth’s atmosphere, the habitable module will separate from the service module. The latter is not protected, it will burn in the atmosphere during its fall while the habitable module will pass through it, protected by its thermal shield. It will end its descent under parachuteparachute. It is supposed to land in the Pacific Ocean off California. The Artemis I mission will then be complete.

We will have to be patient for the rest, depending on the results of this first mission. Artemis II should not take place before 2023, or even 2024. It will be the first mission of the program with astronauts on board but they will not land on the Moon. They will just go around it in “dress rehearsal” mode, as was the case with Apollo 10. It is the Artemis III mission that will return astronauts to the surface of our natural satellite, including the first lunar walk of a woman from history.

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