Intuitive Machines’ lunar south pole landing attempt highlights challenges for Artemis

The Athena lander photographed on its side in a lunar crater. 

As any space watcher knows, landing on the moon is no easy feat. Of the 58 landings attempted since 1958, only 28 have been successful.

The latest attempt by Intuitive Machines of Texas might contain specific lessons for NASA’s ambitions to return humans to the moon under the Artemis program, as well as the future robotic landers that the agency has funded under its Commercial Lunar Payload Services, or CLPS, program. The company’s Athena lander tipped over inside a crater shortly after touching down on the moon in early March. It was the closest to the lunar south pole that any spacecraft has journeyed, but this orientation prevented Athena from charging its batteries, and the IM-2 mission concluded about 24 hours later.

It’s a vivid illustration of the stakes for the first crewed landing, Artemis III, which is also bound for the south pole in 2027, pending any adjustment from the Trump administration. NASA has yet to choose a specific landing site from its short list of nine locations, but the general plan is that a SpaceX Starship lander would ferry two astronauts from lunar orbit to the surface.

If the lander tips over, the astronauts would likely be “stuck in the vehicle,” says Dan Dumbacher, a professor of engineering practice in Purdue University’s School of Aeronautics and Astronautics and former CEO of AIAA. “There’s no way for them to get off the surface” unless you can “get the lander back upright,” he says. “I would think that’s rather difficult to do.”

Of particular concern to Dumbacher is Starship’s 50-meter height — nearly 10 times more than Athena, which was roughly as tall as a giraffe — which could make flight control more challenging. With a taller vehicle, there is a greater risk that the lander’s momentum will continue after landing and tip the craft over. Dumbacher notes that designing the lander to have a lower center of mass could reduce this concern.

For its part, Intuitive Machines says that Athena’s height did not contribute to the tipping. Rather, the company identified “three primary contributors,” two of which were related to the lunar south pole’s topography, President and CEO Steve Altemus said during a May 13 earnings call. The mountainous terrain and the low angle of sunlight created “long shadows and dim lighting conditions that challenged the precision capability of our landing system,” he said, which meant that Athena’s landing software “could not accurately account for how craters appear at lower altitudes with south pole lighting conditions as you approach the landing site.”

Those difficulties are the most relevant for Artemis III, says Jonathan McDowell, an astrophysicist with the Center for Astrophysics, Harvard & Smithsonian in Massachusetts who maintains a catalog of space activity. In contrast to the flat equatorial planes visited by the Apollo astronauts, Artemis crews will be landing in terrain covered in jagged rocks, craters and mountains.

“I do worry about its stability in landing in this sort of terrain,” he says, referring to Starship. “It’s hard to find a spot to set down without falling over, but it’s also hard because the radio signals bounce off the mountains, and so you get interference.”

Intuitive might have experienced a version of this, based on Altemus’ remarks: “In the final phase of descent, we saw signal noise and distortion that did not allow for accurate altitude readings.”

In an emailed response to questions, a NASA spokesperson said only that “the agency’s evaluation for a potential Artemis III landing site near the lunar south pole is ongoing.” SpaceX did not respond to a request for comment.

The current Artemis plan builds in an opportunity for mission designers to see how Starship might fare in a south pole landing before astronauts are put aboard. SpaceX’s $2.9 billion contract requires the company to land an unoccupied Starship on the moon before Artemis III. NASA and SpaceX have not yet announced a date for this demo, but the agency’s fiscal 2025 budget request said it was scheduled for 2026.

McDowell thinks that is a wise strategy but notes that it might make more sense for NASA to shift Artemis III and other early landings to regions of the moon that have smoother terrain. Then, a south pole landing could be attempted at a later stage. “It might be on the ambitious side to go straight there,” he says. “They might be better served doing a demonstration in some nice [flat] area.”

Even then, crews might face challenges. “Neil Armstrong still had to steer away from rocks,” says Mike Loucks, CEO of the Washington state company Space Exploration Engineering, which has been involved in several robotic moon landing attempts. He was referring to Armstrong taking manual control of the Eagle because the original trajectory would have set the lander down in the middle of a crater.

As for Intuitive Machines, Altemus said the company is taking the lessons from IM-2 and applying them to its next mission, which remains “on schedule” for an October launch to the Reiner Gamma site near the moon’s equator. Intuitive plans to more rigorously test this IM-3 lander and equip it with additional altimeters and lighting sensors, as well as an expanded onboard crater database. Under NASA’s CLPS program, Intuitive has been contracted for four landings and received a combined $359.4 million.

“Moving forward, we will succeed — land softly, land upright, land ready to operate,” said Altemus.