August 19, 2022

— NASA has identified 13 regions located near the lunar south pole where astronauts may next land on the moon, possibly as soon as 2025.

The space agency on Friday (Aug. 19) revealed the general areas that a team of scientists and engineers determined could meet the requirements for the planned Artemis III mission, including seeking out water ice in the permanently shadowed craters of the lunar south pole. Each of the regions contain multiple potential sites where SpaceX's Starship human landing system (HLS) — NASA's chosen lunar lander for the Artemis III mission — could safely touch down with the first humans to explore the lunar surface since the last Apollo mission more than 50 years ago.

"Knowing that Apollo 17 would be the last Apollo mission to the moon, astronaut Eugene Cernan reflected on his expectation that time he stated, 'The theme of our mission is that this isn't the end. We've just begun to crawl ... We're just now hoping that we can learn to begin to walk and press onto the future," Jacob Bleacher, chief exploration scientist at NASA Headquarters, said Friday in a call with reporters. "Well, sir, we accept the challenge."

"Skylab, shuttle, the International Space Station — they have all taught us how to survive and thrive in low Earth orbit, meaning we're now ready to take that walk," said Bleacher. "Discussing the regions where our Artemis III mission can land is our exciting first step on that path."

The Artemis III mission, targeted for 2025, will see two astronauts explore the lunar south pole for six to seven days before rejoining their two crewmates aboard an Orion spacecraft to return to Earth. Before then, Artemis I will test Orion and its rocket, the Space Launch System (SLS), on an uncrewed trip around the moon as soon as later this month. Artemis II in 2024 will fly four astronauts into lunar orbit.

An uncrewed test landing by SpaceX's Starship HLS is also planned before the Artemis III mission begins.

Artemis III landing region candidates. Click to view and enlarge video in new window. (NASA)

Each of the chosen landing regions for Artemis III is located within six degrees of latitude of the lunar south pole and, collectively, contain diverse geologic features. Together, the regions provide options for all potential Artemis III launch window opportunities. The specific landing sites will be tightly coupled to the timing of the mission, so identifying multiple regions ensures flexibility to launch throughout the year.

The regions were also evaluated for their ability to support a safe landing, using criteria that included terrain slope, ease of communications with Earth and lighting conditions.

"The Apollo missions took full advantage of the lighting conditions near the equator, knowing that they would have the equivalent of 14 continuous Earth days of light, once per month, so they could land in those locations and know that they would have a stretch of 9 to 10 days of light," Bleacher said. "Any of these locations [at the south pole] is not in light all the time ... so we have to model and understand exactly when they do enter into light and for how long."

"It's the one of the the conditions we're looking at," he said. "We would need [a site] to be in light for Artemis III throughout the duration of the mission, between six and seven days long. We need that stretch of sunlight."

The analysis team weighed other landing criteria with specific Artemis III science objectives, including the goal to land close enough to a permanently shadowed area to allow the crew to conduct a moonwalk while limiting any disturbances to the area when landing. This will allow astronauts to collect samples and conduct scientific analysis in an uncompromised area, yielding important information about the depth, distribution and composition of water ice confirmed to be at the moon's south pole.

"It's a long way away from the Apollo sites," said Sarah Noble, Artemis lunar science lead for NASA's planetary science division. "You think about Apollo, all six Apollo landing sites were in sort of the central part of the near side [of the moon]. Now we're going someplace completely different with ancient geologic terrain."

"Some of the coldest places in the solar system exist there and those cold traps are places where we believe that water and other volatiles get trapped. It is so cold there that molecules bouncing around the moon bounce into one of these cold traps and can't get back out again," said Noble. 'So we are very excited, not only [for water] as a resource, but also from a science perspective to understand what is present in the in these places."

The Artemis III regions include the rim of Amundsen crater; the northeastern and western rims of Nobile crater; the Leibnitz Beta plateau; the rim of Faustini crater; an elevated region between Shackleton crater and Slater crater; the Malapert Massif; two locations along a high standing ridge that connects Shackleton and the de Gerlache craters; the rim of Haworth crater; two locations along the rim of de Gerlache crater, itself; and a massif between the de Gerlache crater and the Kocher craters.

NASA plans to discuss the 13 regions with the broader science and engineering communities to solicit more input about the merits of each area. The feedback from these meetings and workshops will inform specific site selections in the future, and NASA may identify additional regions for consideration. The agency will also continue to work with SpaceX to confirm Starship's landing capabilities and assess the options accordingly.

NASA plans to select sites within the desired regions after identifying the Artemis III mission's target launch dates, which will then dictate transfer trajectories and the conditions on the lunar surface.