Intuitive Machines confirms Athena fell over at landing; ends mission
Intuitive Machines today officially ended its Athena lunar lander mission after it released a picture taken from the top of the lander showing clearly that it had fallen over on its side after landing.
That picture, cropped, reduced, and brightened to post here, is to the right. You can clearly see two of the landing legs in the air, with the horizon in the background.
“With the direction of the sun, the orientation of the solar panels, and extreme cold temperatures in the crater, Intuitive Machines does not expect Athena to recharge,” the company stated. “The mission has concluded and teams are continuing to assess the data collected throughout the mission.”
This is the second Intuitive Machines lunar lander to tip over. More and more it does appear that the tall design of this lander is fundamentally flawed. The artist rendering to the right illustrates this. Most unmanned lunar landers are much wider than they are tall. Intuitive Machines’ Nova design has the lander’s height matching the spread of its legs. It creates a center of gravity high enough that the lander will tip over too easily if conditions are not perfect.
The company denies this, saying the center of gravity is much lower than this graphic makes it appear, but the proof is in the pudding. Their design has tried to land on the Moon twice, and both times the lander tipped over.
It is not clear what the company can do to fix this. Expanding its diameter to lower its height is a major redesign. It also might make the lander too wide to fit inside most rocket fairings. A better solution might be to redesign the legs, making their spread wider, and even increasing their number.
Fortunately, NASA’s shift to capitalism in space has produced a number of different companies building lunar landers. Firefly’s Blue Ghost is clearly a success. In June Ispace will make its second attempt to soft land its private lander design on the Moon. And Astrobotic has a contract to try again after it had a fuel line leak after launch last year that prevented it from even attempting a landing.
And of course, Intuitive Machines is still in the game. It has a contract for one more landing mission, plus a mission to put two data relay satellites in lunar orbit.
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Intuitive Machines today officially ended its Athena lunar lander mission after it released a picture taken from the top of the lander showing clearly that it had fallen over on its side after landing.
That picture, cropped, reduced, and brightened to post here, is to the right. You can clearly see two of the landing legs in the air, with the horizon in the background.
“With the direction of the sun, the orientation of the solar panels, and extreme cold temperatures in the crater, Intuitive Machines does not expect Athena to recharge,” the company stated. “The mission has concluded and teams are continuing to assess the data collected throughout the mission.”
This is the second Intuitive Machines lunar lander to tip over. More and more it does appear that the tall design of this lander is fundamentally flawed. The artist rendering to the right illustrates this. Most unmanned lunar landers are much wider than they are tall. Intuitive Machines’ Nova design has the lander’s height matching the spread of its legs. It creates a center of gravity high enough that the lander will tip over too easily if conditions are not perfect.
The company denies this, saying the center of gravity is much lower than this graphic makes it appear, but the proof is in the pudding. Their design has tried to land on the Moon twice, and both times the lander tipped over.
It is not clear what the company can do to fix this. Expanding its diameter to lower its height is a major redesign. It also might make the lander too wide to fit inside most rocket fairings. A better solution might be to redesign the legs, making their spread wider, and even increasing their number.
Fortunately, NASA’s shift to capitalism in space has produced a number of different companies building lunar landers. Firefly’s Blue Ghost is clearly a success. In June Ispace will make its second attempt to soft land its private lander design on the Moon. And Astrobotic has a contract to try again after it had a fuel line leak after launch last year that prevented it from even attempting a landing.
And of course, Intuitive Machines is still in the game. It has a contract for one more landing mission, plus a mission to put two data relay satellites in lunar orbit.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
The criticism of IM is mounting on this front, and it *is* worth noting that Intuitive Machines’ explanation of their low center of gravity on Nova-C is not an argument ender, because the tall design’s risk is not completely obviated by a low CoM. Phil Metzger made this point rather well earlier today on X:
https://x.com/DrPhiltill/status/1898037345011552664
In any event, it is clear that this is not the only problem that seemed to be at work on Athena. The laser altimeter actually functioned this time, but in an unexpectedly “noisy” way, for starters, and the lander had no alternative altitude instrumentation to fall back on. And the landing approach software seems like it might be suspect as well. After two consecutive failures (we can argue about the degree or characterization of those failures) that both resulted in tip-overs, IM has some hard soul-searching to do now, and not just to appease their shareholders. I think they are learning, but the learning is coming at a steep price. As someone wiser than me has said about aerospace programs, “Experience is hard won in complex technical endeavors.” IM has used up a lot of runway to gather its experience — and a not insignificant amount of NASA funds and instrumentation effort. They appear to have the funds to do a third landing, but I think they can’t easily afford a third tip-over.
“The company denies this, saying the center of gravity is much lower than this graphic makes it appear, but the proof is in the pudding.”
The proof is actually in the green cheese.
(Um . . . Sorry . . .)
Why don‘t they simply copy the Surveyor design? That vehicle was a complete success, and even “hopped” once to prove that the surface was solid. None of the Surveyors ever tipped over on landing!
“None of the Surveyors ever tipped over on landing!”
An excuse to tell a favorite story: as a young boy went to a talk by an astronaut and his NASA PR handler- this is the days before Apollo. Audience member asks what is greatest danger moon landing crews will face, and PR guy jumps in and gives some forgettable PR-speak answer that sort of irritated the astronaut!
Now this was before any Surveyors had landed, but during the time when they should have but were suffering delays. And remember their job was to determine the surface characteristics for astronauts’ safety, so they were holding up the show!
So the astronaut chips in: “Actually the danger we really worry about is that we’ll get hit by one of those Surveyors finally landing!” Audience roared, but PR guy was NOT amused!
I bet the craft shuts it engines down to early and bounces.
It could be programed to shut down at contact but the rigilith kick up could be throwing off the landing sensors. It could think its down when its not.
I am sure they thought of it but bad sensor placement could throw things off.
“The company denies this, saying the center of gravity is much lower than this graphic makes it appear, but the proof is in the pudding.”
Here might be a possible reason—sometimes the simplest reasons are the best, after all.
When they weighed the lander—perhaps they did so when it was full.
The CG was lower then—but they forgot that burns would deplete the fuel.
That’s my guess.
To answer David M. Cook:
“Why don‘t they simply copy the Surveyor design?”
Because that is an admission that the steely-eyed old-spacers knew more than the new-space brats.
For a craft to just fall over seems so amateurish. It should never have happened. Even a one-year-old child learns from his mistakes after a few bad falls and begins to run with confidence.
Depleted fuel tanks near the thruster on the bottom of the craft, as Jeff Wright suggests, would be a horrifying mistake if it was overlooked… Engineering by “wishing” something won’t happen. Without the precautions to prevent the “what if” scenario like uneven ground, rock under landing pad, or the example that pzatchok gave of dust/Rock grains covering the sensors giving false readings!
Replacing pads with spikes (like tripods have) would stick the landing, especially if applied from telescoping legs from 10 feet up before the regolith is stirred up. The ladder could settle vertically under physical control. Simple without adding weight.
Onboard gyroscopes could be very useful to not only land vertically, but keeping the craft vertical until leading legs can adjust… if the legs are adjustable? I don’t know if it had that capability. (A reasonable precaution on the uneven ground, used throughout the heavy equipment industry.)
Perhaps revisiting “ancient technology” that was performed on Mars? Remember the lander that lowered the rover to the surface? That prevented the dust that would damage both systems. Proving thrusters mounted at the top of the craft functioned extremely well.
Or the lander that was deployed inside an inflatable ball? It just rolled to it’s flat spot. (that would seem a desirable choice for the “Shackleton Crater water sampling and analysis mission” to reach/roll to the bottom to do the best science)
My own analysis, from an amateur science hobbyist, is the “thrust from the bottom of a top-heavy probe” did not take into account the diversion/redirection of thrust from the surface.
When you as an adult take a step, the balancing mechanism of the top heavy apparatus automatically keeps you vertical as you thrust forward… until you step on “ice” which gives you a sideways thrust factor that once in motion is hard to counterbalance… in this situation, think staying vertical with one thruster on your foot. You’re doing fine as you lower yourself to the ground and then suddenly it pushes sideways. (Play with the nozzle on a garden hose to feel the effect as it comes close to the surface of an object) That’s why Jetpacks that people play with have thrusters at the top of the center of mass.
If they persist with this design, I would suggest putting hoops around the circumference, so it can roll to a better Position should it fall over. (after all, they perfected this landing style) Motorized bicycle wheels for when it tips over so they can re-position Solar panels to follow the sun or find a better location by being mobile, I can’t help but think of a wheelchair. A simple design for stability! What’s the alternative? A useless multimillion dollar paperweight laying on its side.
David M. Cook asked: “Why don‘t they simply copy the Surveyor design?”
Perhaps Surveyor did not carry as much payload as the NASA customer now wants taken to the Moon.
________________
Ray Van Dune,
That got me laughing. Looks like that one doesn’t get old.
It’s worth remembering that the Surveyors did not have a 1.000 batting average: Two of the seven were failures, crashing into the Moon.
I remembered who the Surveyor-wisecracking astronaut was: the late Karl Henize, a scientist-astronaut who made it to space in the Shuttle Challenger (fortunately not on the fatal flight).
Henize passed away in 1993 during a Mount Everest expedition while testing NASA equipment.
BTW, I do not wish to be understood as being critical of the Surveyor program. It was a success! It accomplished its mission, which was characterizing lunar regolith at key sites sufficiently to assure NASA that it could safely land an Apollo LM on the surface. And given what a steep learning curve NASA and JPL had had with just getting missions to the Moon (as in, just crashing them into the moon!) on the Ranger program, the success of getting 5 landings there in 1966-67 is really astounding. The Surveyor engineering team really earned their salaries.
But it is important to understand its context and its design. NASA spent what amounts to over $4 billion in current dollars, making Surveyor basically a flagship science program. It wasn’t required to carry much at all of any science instrumentation, just a simple camera and, later, an alpha scatter instrument. It was designed to descend to almost 4 meters off the surface using hypergolic verniers, and then just drop the final 4 meters onto the surface. So, a pretty rough landing, and it would have been rough on any instrumentation on board. They probably also had some luck in not dropping on any boulders.
It’s true that Surveyor had a very robust profile to minimize chances of tipping. Why did IM opt for a taller lander (however low its CoM)? Well, it’s supposed to operate at the pole, where the Sun remains low on the horizon, so they wanted to maximize exposure on the solar array. There were multiple ways to address that, but they chose to increase the height of the main body.
All that said, the leg design may need reworking, even aside from the issues with the laser altimeter and the landing software. Scott Manley believes that an image from the Yaoki rover on board suggests one of the legs snapped (again!). These legs also, unlike Surveyor and the LM, do not have crushable leg struts. IM got a lot more things right this time around, but I think there is little dispute that they have some serious homework ahead on all of these issues related to Nova C’s landing profile. I hope they can figure it out before they run out of runway.
Scott’s tweet on this: https://x.com/DJSnM/status/1898751088784007576
Final thought: The CLPS program isn’t batting as well as we might like. But the good news is that NASA seems to now have what looks like one vendor with a reliable lander — Firefly. Blue Ghost has a payload mass limitation of only 150kg, but if NASA has a payload that it really needs to put on the lunar surface in that mass range, it’s got a lander that it can feel confident about delivering it. That’s not nothing.
By the way, as of Thursday, eight of the 10 payloads on board Blue Ghost – the EDS, LuGRE, SCALPSS, LPV, LISTER, NGLR, RAC, and RadPC – have already met their mission objectives. The payloads still have additional opportunities to gather data over the next 10 days. This mission is definitely an unqualified success already.
https://www.nasaspaceflight.com/2025/03/blue-ghost-im-2-landings/
I hesitate to point out the obvious, because I could be wrong… The picture tells the story fairly well, they “landed in a hole!” Two legs and half the craft in sunlight with what appears as disturbed dirt at the rim of the hole.
Even if the lander was flat/saucer shaped, It would’ve had trouble with this one, similar to the recent landing on a boulder.
Unhindered dissent instrumentation must be improved for successful future attempts. Or design landers fool proof for any terrains.
It looks like a leg did break in some fashion.
This would mean that either it was assembled incorrectly or it landed hard.
My guess it could use some type of hydraulic dampening system on the legs. You can’t just add springs because they would, well, just spring the thing back up and possibly throw it sideways.
Plus each leg could be adjusted to level the craft after landing.
You can not just add gas shocks like we do on earth. The gas would expand in space and make the shock solid. But a non expanding fluid would work fine. Maybe mineral oil.
That’s why I all but live at physdotorg
Lubricants and such are awful in vacuum.
At the risk of sounding like a nut—language and narrative may play a part.
When something is called a “spacecraft,” it is front loaded with perhaps more respect than it deserves…as the word implies sophistication and durability it may not have.
When I look at some of these crazy landers—do you know what I see?
A crazy vending machine…and we all know how much trouble they are.
No—they don’t dispense chips or cola…but if you think of it at least as an appliance—it becomes less of a “black box” and can be seen as more wonky—more deserving of attention—more approachable.
That last…is what is important.
As a kid, I thought tech became more indestructible as it advanced. Apollo suits had some lining in case of micrometeoroids—to to me—that made in tougher than plate armor.
The purpose of having schoolkids build bridges out of spaghetti rods.. to keep eggs from breaking—is really to break kids from relying on the strength of a building material—instead, they must rely on design.
If you think of human made items as wads of bubble gum—and not the adamantine steel of the Krell—you have the proper perspective.
Of course it helps if you’re a jinx like me where stuff breaks if I just look at it.
https://www.lroc.asu.edu/images/1408
IM-2 Athena Seen Obliquely
No, you likely can’t see the vehicle unless you download the 300MB image and zoom in on the white square by X4. Not sure why they did that.