The Athena spacecraft was not exactly flying blind as it approached the lunar surface one week ago. The software on board did a credible job of recognizing nearby craters, even with elongated shadows over the terrain. However, the lander’s altimeter had failed.
So while Athena knew where it was relative to the surface of the Moon, the lander did not know how far it was above the surface.
An important detail, that. As a result, the privately built spacecraft struck the lunar surface on a plateau, toppled over, and began to skid across the surface. As it did so, the lander rotated at least once or twice before coming to a stop in a small, shadowed crater.
“The landing was kind of like sliding into second base,” Steve Altemus, chief executive officer of Intuitive Machines, which built the lander, said in an interview Thursday.
Cold and lonely
It has been a busy and tiring week for the chief of a company that seeks to help lead the development of a lunar economy. Expectations were high for this, the company’s second lunar landing attempt after its Odysseus vehicle became the first private spacecraft to ever make a soft landing on the Moon, last year, before toppling over.
In some ways, this mission was even more disappointing. Because Athena skidded across the lunar surface, it dredged up regolith. When it came to a stop, some of this material was blown up into the solar panels—already in a sub-optimal location on its side. The spacecraft’s power reserves, therefore, were limited. Almost immediately, the team at Intuitive Machines knew their spacecraft was dying.
“We knew we had slid into a slightly shadowed crater, and the temperature was very cold,” Altemus said. “The solar arrays had regolith on them, and they weren’t charging, the ones pointing up, enough to give us sufficient power to power the heaters to keep it warm enough to survive.”
NASA expected Athena to have a reasonable chance of success. Although it landed on its side, Odysseus was generally counted as a win because it accomplished most of its tasks. Accordingly, NASA loaded a number of instruments onto the lander. Most notable among these was the PRIME-1 experiment, an ice drill to sample and analyze any ice that lies below the surface.
A dark day, but not the end
“After landing, mission controllers were able to accelerate several program and payload milestones, including NASA’s PRIME-1 suite, before the lander’s batteries depleted,” the company’s statement said. However, this likely means that the company was able to contact the instrument but not perform any meaningful scientific activities.
NASA has accepted that these commercial lunar missions are high-risk, high-reward. (Firefly’s successful landing last weekend offers an example of high rewards). It is paying the companies, on average, $100 million or less per flight. This is a fraction of what NASA would pay through a traditional procurement program. The hope is that, after surviving initial failures, companies like Intuitive Machines will learn from their mistakes and open a low-cost, reliable pathway to the lunar surface.
Even so, this failure has to be painful for NASA and Intuitive Machines. The space agency lost out on some valuable science, and Intuitive Machines has taken a step backward with this mission rather than moving forward as it had hoped to do.
Fortunately, this is unlikely to be the end for the company. NASA has committed to a third and fourth mission on Intuitive Machines’ lander, the next of which could come during the first quarter of 2026. NASA has also contracted with the company to build a small network of satellites around the Moon for communications and positioning services. So although the company’s fortunes look dark today, they are not permanently shadowed like the craters on the Moon that NASA hopes to soon explore.
Inside a small control room, during the middle of the day on Thursday local time in Texas, about a dozen white-knuckled engineers at a space startup named Intuitive Machines started to get worried. Their spacecraft, a lander named Athena, was beginning its final descent down to the lunar surface.
A little more than a year had passed since the company’s first attempt to land on the Moon with a similarly built vehicle, Odysseus. Due to problems with that spacecraft’s laser rangefinder, it skidded into the Moon’s surface and toppled over.
So engineers at Intuitive Machines had checked, and re-checked the laser-based altimeters on Athena. When the lander got down within about 30 km of the lunar surface, they tested the rangefinders again. Worryingly, there was some noise in the readings as the laser bounced off the Moon. However, the engineers had reason to believe that, maybe, the readings would improve as the spacecraft got nearer to the surface.
“Our hope was that the signal to noise would improve as we got closer to the Moon,” said Tim Crain, chief technology officer for Intuitive Machines, speaking to reporters afterward.
It didn’t. The noise remained. And so, to some extent, Athena went down to the Moon blind. The spacecraft’s propulsion system, based on liquid oxygen and methane, and designed in-house, worked beautifully. But in the final moments, the spacecraft did not quite know where it was relative to the surface.
Probably lying on its side
Beyond that, Crain and the rest of the company, including its chief executive Steve Altemus, could not precisely say what happened. After Athena landed, the engineers in mission control could talk to the spacecraft, and they were able to generate some power from its solar arrays. But precisely where it was, or how it lay on the ground, they could not say a few hours later.
Based on a reading from an inertial measurement unit inside the vehicle, most likely Athena is lying on its side. This is the same fate Odysseus met last year, when it skidded into the Moon, broke a leg, and toppled over.
Because the space agency now has some expectation that Intuitive Machines will be fully successful with its second landing attempt, it has put some valuable experiments on board. Principal among them is the PRIME-1 experiment, which has an ice drill to sample any ice that lies below the surface. Drill, baby, drill.
The Athena lander also is carrying a NASA-funded “hopper” that will fire small hydrazine rockets to bounce around the Moon and explore lunar craters near the South Pole. It might even fly into a lava tube. If this happens it will be insanely cool.
Because this is a commercial program, NASA has encouraged the delivery companies to find additional, private payloads. Athena has some nifty ones, including a small rover from Lunar Outpost, a data center from Lonestar Data Holdings, and a 4G cellular network from Nokia. So there’s a lot riding on Athena‘s success.
So will it be a success?
“Of course, everybody’s wondering, are we gonna land upright?” Tim Crain, Intuitive Machines’ chief technology officer, told Ars. “So, I can tell you our laser test plan is much more comprehensive than those last time.”
During the first landing about a year ago, Odysseus‘ laser-based system for measuring altitude failed during the descent. Because Odysseus did not have access to altitude data, the spacecraft touched down faster, and on a 12-degree slope, which exceeded the 10-degree limit. As a result, the lander skidded across the surface, and one of its six legs broke, causing it to fall over.
Crain said about 10 major changes were made to the spacecraft and its software for the second mission. On top of that, about 30 smaller things, such as more efficient file management, were updated on the new vehicle.
In theory, everything should work this time. Intuitive Machines has the benefit of all of its learnings from the last time, and nearly everything worked right during this first attempt. But the acid test comes on Thursday.
The company and NASA will provide live coverage of the attempt beginning at 11: 30 am ET (16: 30 UTC) on NASA+, with landing set for just about one hour later. The Moon may be a harsh mistress, but hopefully not too harsh.
Enlarge/ The second Intuitive Machines lander is prepared for hot-fire testing this week.
Intuitive Machines
One of the miracles of the Apollo Moon landings is that they were televised, live, for all the world to see. This transparency diffused doubts about whether the lunar landings really happened and were watched by billions of people.
However, as remarkable a technical achievement as it was to broadcast from the Moon in 1969, the video was grainy and black and white. As NASA contemplates a return to the Moon as part of the Artemis program, it wants much higher resolution video and communications with its astronauts on the lunar surface.
To that end, NASA announced this week that it had awarded a contract to Houston-based Intuitive Machines for “lunar relay services.” Essentially this means Intuitive Machines will be responsible for building a small constellation of satellites around the Moon that will beam data back to Earth from the lunar surface.
“One of the requirements is a 4K data link,” said Steve Altemus, co-founder and chief executive of Intuitive Machines, in an interview. “That kind of high fidelity data only comes from a data relay with a larger antenna than can be delivered to the surface of the Moon.”
About the plan
This is part of NASA’s plan to build a more robust “Near Space Network” for communications within 1 million miles of Earth (the Moon is about 240,000 miles from Earth). Intuitive Machines’ contract is worth as much as $4.82 billion over the next decade, depending on the level of communication services that NASA chooses to purchase.
The space agency is also expected to award a ground-based component of this network for large dishes to receive signals from near space, taking some of this burden off the Deep Space Network. Altemus said Intuitive Machines has also bid on this ground component contract.
The Houston company, with its IM-1 mission, made a largely successful landing on the Moon in February. A second lunar landing mission, IM-2, is scheduled to take place in late December or January, a few months from now. Funded largely by NASA, the IM-2 mission will carry a small drill to the South Pole of the Moon to search for water ice in Shackleton Crater.
Then, approximately 15 months from now, the company is planning to launch another lander, IM-3. This mission is likely to carry the first data-relay satellite—each is intended to be about 500 kg, Altemus said, but the final design of the vehicles is still being finalized—to lunar orbit. Assuming this first satellite works well, the two following IM missions will each carry two relay satellites, making for a constellation of five spacecraft orbiting the Moon.
Two of the satellites will go into polar orbits and serve NASA’s Artemis needs at the South Pole, Altemus said. Two more are likely to go into halo orbits, and a fifth satellite will be placed into an equatorial orbit. This will provide full coverage of the Moon not just for communications, but also for position, navigation, and timing.
Intuitive Machines rising
A former deputy director of Johnson Space Center, Altemus founded Intuitive Machines in 2013 along with an investor, Kam Ghaffarian, and an aerospace engineer named Tim Crain. It hasn’t always been easy. Development of Intuitive Machines’ Nova C lander took years longer than anticipated; there were setbacks such as a propellant tank failure, and money was at times tight.
In part to address these financial difficulties, the company went public in 2023, at the tail end of the mania in which space companies were becoming publicly traded via special purpose acquisition companies, or SPACs. Many space companies that went public this way have struggled mightily, and Intuitive Machines has also faced similar pressures.
“It’s been a challenge,” Altemus said. “We went public in 2023, and navigating that was the story of last year, as well as getting to the launch pad.”
But then good things started happening. Despite some technical troubles, including the failure of its altimeter, the company’s first lander managed a soft touchdown on the Moon on its side. Even with this untinended orientation, the Intuitive Machines-1 mission still managed to complete the vast majority of its science objectives. In August, the company won its fourth task order from NASA—essentially a lunar delivery mission—under the Commercial Lunar Payload Services program.
And then the company won the massive data relay contract this week.
“This has really been a transformational year for us,” Altemus said. “The vision for the company is finally coming together.”
Enlarge / A photo of Odysseus the moment before it gently toppled over.
Intuitive Machines
After six days and the public release of new images, engineers have finally pieced together the moments before, during, and after the Odysseus lander touched down on the Moon.
During a news conference on Wednesday, the chief executive of Intuitive Machines, Steve Altemus, described what his company has learned about what happened last Thursday evening as Odysseus made its powered descent down to the Moon.
From their control room in Houston, the mission operators watched with fraying nerves, as their range finders had failed. A last-minute effort to use altitude data from a NASA payload on board failed because the flight computer on board Odysseus could not ingest it in time. So the lander was, in essence, coming down to the Moon without any real-time altimetry data.
The last communication the operators received appeared to show that Odysseus had touched down on the Moon and was upright. But then, to their horror, all telemetry from the spacecraft ceased. The data on the flight controllers’ consoles in Houston froze. They feared the worst.
Skidding down to the Moon
About 10 minutes later, the lander sent a weak signal back. In that initial trickle of data, based on the lander’s inertial measurement unit, it appeared that Odysseus was partly on its side. But there were confusing signals.
On Wednesday, Altemus explained what the team has since pieced together. Because of the lack of altimetry data, Odysseus thought it was about 100 meters higher above the lunar surface than it actually was, so as it touched down it was traveling about three times faster than intended, about 3 meters per second. It was also moving laterally, with respect to the ground, at about 1 meter per second.
“We hit harder than expected and skidded along the way,” Altemus explained.
As it impacted and skidded, the spacecraft’s main engine was still firing. Then, just as the spacecraft touched down more firmly, there was a spike in the engine’s combustion chamber. This is consistent with the bell-shaped engine nozzle coming into contact with the lunar surface.
It is perhaps worth pausing a moment here to consider that this spacecraft, launched a week earlier, had just made an autonomous landing without knowing precisely where it was. But now it found itself on the Moon. Upon impact, one or more of the landing legs snapped as it came down hard. Then, at that very moment, with the engine still burning, an onboard camera snapped an image of the scene. Intuitive Machines published this photo on Wednesday. It’s spectacular.
“We sat upright, with the engine firing for a period of time,” Altemus said. “Then as it wound down, the vehicle just gently tipped over.”
Based on the gravity of the Moon, Intuitive Machines and NASA calculated that it took about two seconds to tip over. The lander fell on its side, with a helium tank or radio shelf contacting the Moon. This protrusion, combined with the 12-degree slope of the terrain, means that Odysseus is now gently leaning on the lunar surface at about a 30-degree angle. On Tuesday, the spacecraft returned an image that verified these conclusions.
“We have that photo now to confirm that’s the orientation,” Altemus said.
Sleepy time
As Intuitive Machines has better understood the situation and the status of its vehicle, it has been able to download a torrent of data. NASA has gotten valuable information from all six of its payloads on board, said a project scientist for the space agency, Sue Lederer. As of Wednesday, NASA had been able to download about 50MB of data. The baseline for success was a single bit of data.
But time is running out as the Sun dips toward the horizon. Odysseus will run out of power as soon as Wednesday evening, entering the long lunar night. In about three weeks, as sunlight starts to hit the spacecraft’s solar panels again, Intuitive Machines will try to wake up the spacecraft. The odds are fairly long. The chemistry of its lithium-ion batteries doesn’t like cold, and temperatures will plummet to minus-280° Fahrenheit (minus-173° Celsius) in a few days. That may wreck the batteries or crack the electronics in the flight computer.
Yet hope remains eternal for a spacecraft its operators have taken to affectionately calling Odie. It has defied the odds so far. “He’s a scrappy little dude,” Lederer said. “I have confidence in Odie at this point.”
Enlarge/ Odysseus passes over the near side of the Moon following lunar orbit insertion on February 21.
Intuitive Machines
For the first time in more than half a century, a US-built spacecraft has made a soft landing on the Moon.
There was high drama and plenty of intrigue on Thursday evening as Intuitive Machines attempted to land its Odysseus spacecraft in a small crater not all that far from the south pole of the Moon. About 20 minutes after touchdown, NASA declared success, but some questions remained about the health of the lander and its orientation. Why? Because while Odysseus was phoning home, its signal was weak.
But after what the spacecraft and its developer, Houston-based Intuitive Machines, went through earlier on Thursday, it was a miracle that Odysseus made it at all.
Losing your way
The landing attempt was delayed by about two hours after mission controllers had to send a hastily cobbled together, last-minute software patch up to the lander while it was still in orbit around the Moon. Patching your spacecraft’s software shortly before it makes its most critical move is just about the last thing a vehicle operator wants to do. But Intuitive Machines was desperate.
Earlier on Thursday, the company realized that its navigation lasers and cameras were not operational. These rangefinders are essential for two functions during landing: terrain-relative navigation and hazard-relative navigation. These two modes help the flight computer on Odysseus to determine precisely where it is during descent—by snapping lots of images and comparing them to known Moon topography—and to identify hazards below, such as boulders, in order to find a safe landing site.
Without these rangefinders, Odysseus was going to faceplant into the Moon. Fortunately, this mission carried a bunch of science payloads. As part of its commercial lunar program, NASA is paying about $118 million for the delivery of six scientific payloads to the lunar surface.
One of these payloads just happened to be the Navigation Doppler Lidar experiment, a 15-kg package that contains three small cameras. With this NDL payload, NASA sought to test out technologies that might be used to improve navigation systems in future landing attempts on the Moon.
The only chance Odysseus had was if it could somehow tap into two of the NDL experiment’s three cameras and use one for terrain-relative navigation and the other for hazard-relative navigation. So, some software was hastily written and shipped up to the lander. This was some true MacGyver stuff. But would it work?
