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Artemis II, Artemis III and beyond.

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Science|Artemis II, Artemis III and beyond.

https://www.nytimes.com/2022/12/11/science/artemis-ii-astronauts-moon.html

With the uncrewed Artemis I test mission back on Earth, NASA is pursuing plans to return astronauts first to the moon’s orbit, and then lunar surface.

The moon's surface fills the frame with numerous craters and other surface features visible.
A view of the moon’s surface captured by the Orion capsule on Dec. 5 during the Artemis I mission.Credit…NASA

Kenneth Chang

The uncrewed Artemis I test flight is over, but Artemis II — what will be the first with astronauts aboard — will not be until at least 2024.

In an interview this summer, Bill Nelson, the NASA administrator, vented about the gap between Artemis I and Artemis II. “I have been raising Cain,” he said. “If this first mission is successful and meets the goals and is safe for the astronauts, why can’t we get it quicker than two years?”

Mr. Nelson said that years ago, to save money, NASA decided to reuse some of the electronics equipment, known as avionics, from the Artemis I Orion capsule in the new Orion capsule for Artemis II. “It takes them two years to take the avionics out and redo them,” Mr. Nelson said, “which is very frustrating to me, but it is what it is.”

There will be four astronauts aboard Artemis II. Three will be from NASA, and one will be Canadian, part of the agreement spelling out the Canadian Space Agency’s participation in the Artemis program. NASA has not yet announced who will fly on the mission.

The trajectory of Artemis II will be fairly simple. After launch, the second stage of the Space Launch System will push Orion into an elliptical orbit that loops as far out as 1,800 miles above Earth, giving the astronauts time to see how Orion’s systems work.

Then, when Orion speeds around again, its engine will fire to send it toward the moon. For Artemis II, the Orion spacecraft will not enter orbit around the moon; it will instead use the moon’s gravity to sling back to Earth for a Pacific Ocean splashdown. The entire trip should take around 10 days.

The big event will be Artemis III, currently scheduled for no earlier than 2025.

During the Apollo moon landings in the 1960s and 1970s, the lunar lander was packed into the Saturn V rocket. The lander for Artemis III will be a version of a Starship rocket built by SpaceX. The lunar Starship will be launched separately. Additional Starships would then launch to refill the propellant tanks of the lunar Starship before it left Earth orbit.

At the moon, the Starship lander will enter what is known as a near-rectilinear halo orbit, or N.R.H.O.

Halo orbits are influenced by the gravities of two bodies — in this case, the Earth and the moon — which help to make the orbit highly stable, minimizing the amount of propellant needed to keep a spacecraft circling the moon. A spacecraft in this orbit also never passes behind the moon, where communications with Earth are cut off.

Once Starship is in orbit around the moon, the Space Launch System rocket will send four astronauts in an Orion capsule to the same near-rectilinear halo orbit. The Orion will dock with the Starship. Two of the astronauts will move to the Starship rocket, landing somewhere near the moon’s South Pole, while the other two astronauts will remain in orbit in Orion.

After about a week on the surface, the two moon-walking astronauts will blast off in Starship and rendezvous with Orion in orbit. Orion will then take the four astronauts back to Earth.

In August, NASA announced 13 potential landing sites near the moon’s south pole.

The astronauts aboard Artemis IV will head to Gateway, a space station-like outpost that NASA will build in the same near-rectilinear halo orbit used for Artemis III. That mission will use a Space Launch System rocket with an upgraded second stage, providing enough power to take along Gateway’s habitat module.

Originally, NASA planned for Artemis IV to focus on construction of Gateway. But this year, it decided that the mission would also include a trip to the lunar surface. Last month, NASA announced SpaceX would provide the lander for Artemis IV.

For Artemis V and later missions, the lunar lander will be docked at Gateway. Astronauts will arrive at the Gateway on Orion, then move to the lander for the journey to the lunar surface.

NASA is now considering bids for a different company to provide the lander for Artemis V.

Among the companies that may be bidding to build a competing lander are Blue Origin, the rocket company started by Jeff Bezos, the founder of Amazon.

NASA would then run a competition for future lunar landers similar to how it hired companies to take cargo and astronauts to the International Space Station.

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