Well, the definition of 0ºC is based on the freezing point of water at one atmosphere of pressure, which isn't super relevant on the Moon. You could give it in K but that's not very relatable.
-280F, -173C, or 100K is not relatable to anyone except niche researchers. Maybe slap in the extra few people who happen to work with liquid helium and you are still talking about 0% of the population.
You would think either they could parameterise all units or a plausible browser extension could convert elephants to swimmingpools and King's thumbs to badly measured fractions of a diameter.
> 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.
Oh yeah, we've all Kerbaled it in like that at one point or another.
Scott Manley and I agree that altitude signal shouldn't matter if navigation is correct. Athena simply risked touchdown, and it didn't find a flat spot, it found a hole.
He's saying modern spacecraft can null out the horizontal velocity to land, but without an altimeter, you don't necessarily know when to do so, nor when to give the thrusters a little boost to avoid an obstacle you're about to hit, like a plateau.
I'm not sure what you find unclear. Navigation was fine - "Athena knew where it was relative to the surface of the Moon" - but without a working altimeter it was kinda fucked for actually touching down.
The top-heavy design didn't help things either. I'll be shocked if they don't go three-for-three on landing sideways given IM3 has the same tall design.
> At his press conference earlier today, Altemus defended the design, saying the spacecraft doesn’t have a high center of gravity because most of its cargo attaches to the base of the vehicle. He said there were no plans for a radical rethink of his company's design.
(We see this in returning F9 first stages, as well.)
Just wait for SpaceX to start trying to land starships on the moon. Also vertically. Also doomed to tip over whenever the surface is slightly out of spec.
Lol. SpaceX has landed on prepared surfaces, concrete pads on land or on large barges. They literally have a big X to mark the target. Let's see them land on some random beach. But that is still peanuts comparted to the moon's surface.
SpaceX has repeatedly and reliably landed vertical stacks. On any body. Out of the engineering problems inherent to HLS, sticking the landing isn’t material because for them, for that team, it isn't as novel a problem as e.g. in-orbit refuelling or getting Raptors to relight on the Moon.
Put another way, just because SpaceX has done it doesn't mean the same problem carries the same risk for a team like IM's.
Looking at this closely, it was working, however it was noisy. I speculate that they didn't correctly anticipate the moon dust problem. Laser rangefinders may not be a workable solution for future landings.
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.
Definitely not a dumb question. The first lander to land on the Moon (after many failures) is pretty amusing. [1] The Soviets a designed a lander that'd be launched right into the Moon but, just before impact would jettison the lander which itself was a highly reinforced ball that was then designed to simply pound into the Moon at 54kph, but survive the crash. The egg then unfurled and finally humanity had achieved a 'soft' landing on the Moon. Somehow it kind of makes one think of a really elaborate egg drop contest paired with a 'what happens if you jump right before the elevator crashes.'
Like another comment mentioned, complexity and size are big issues. Some more are power/mechanics (fluids, such as for hydraulics, and -280F aren't gonna play well together) and then there's the fact that there's not even a guarantee it'd work. Your legs could get damaged, you might end up in an orientation where none of the legs are appropriate, and so on. So you may be adding a whole bunch of complexity for stuff that might not even save you in the situation it was designed for!
Mass. Each kilogram costs what, millions? Hundreds of millions?
There's a small chance that navigation or landing fails in a way that would make those legs useful, and an even smaller chance that they'll save the mission.
Given tight budgets, this is almost certainly not a gamble worth taking
Because:
1. It cannot fail in this mode.
2. Testing is done by the user, test results are sent by telemetry and the fix will be done, when the bug can be reproduced on developer's computers.
Kinda explain why Neil Armstrong burned up all their fuel except for a few seconds scoping out the landing site in paranoia.
Instead of building all these expensive to launch big landers, why not get some pizza-box sized probes into earth orbit AND THEN do like a slo-mo golf shot arcing to where the moon will be for a super slow/soft landing?
Some will fail but if you launch 100 and get 20-30 working, there you go.
As technology progresses, get it down to a shoe-box sized probe and then in 10 years smartphone sized (in 100 years tic-tac sized).
Space applications of all sorts are screaming out for mass production approaches. With so much design work and verification the actual manufacturing cost tends to be trivial by comparison, the work readily adapted to concurrent manufacturing processes.
When I signed on to a Mars mission in 1999, the scientists told me that’s JPL’s approach: instead of extremely expensive, robust, redundant craft, they would begin to make leaner stuff and worry less when it failed...
Around the same time, Mission Control was replacing their bespoke hardware with COTS and trying to minimize the “glue” HW/SW for space systems.
You'll also see that expertise on a particular instrument package is leveraged over and over across multiple missions.
NASA still has amazing educational outreach and makes incredible software, even for mere mortals.
Combine that with leaving the long-range comms (and higher-powered equipment) in lunar orbit as the "master" for all the probes scattered on the surface, and maybe the problem becomes simpler by breaking it in two.
It's definitely possible to target a certain surface location on the moon from low Earth orbit and set off on a trajectory to get there with a single burn. However, as the craft(s) approach the moon and enter its sphere of influence, gravity will kick in and increase their relative velocity to the surface. Another burn (suicide burn if you're feeling lucky) would be needed for the soft touchdown.
The moon is also gravitationally very "lumpy", so some small corrections might be needed along the way as well.
If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering.
Robert Truax, the designer of the Sea Dragon, loved to promote the design paradigm of Big Dumb Boosters. Instead of many small, sophisticated rocket engines, what if we made one big robust one that can take a lickin' and keep on kickin'.
The idea was to relax the mass margins and to create big. dumb. boosters. It's the approach TRW explicitly followed for the Lunar Module engine,
> "There was an amusing but instructive side to this program. TRW farmed-out the fabrication of the engine and its supporting structure, less the injector that they fabricated themselves, to a "job-shop" commercial steel fabricator located near their facility . The contract price was $ 8000. Two TRW executives visited the facility to observe the fabrication process. They found only one individual working on the hardware, and when queried, he did not know nor care that he was building an aerospace rocket engine."
> " I had arrived late to witness the test, and only saw the firing. I was told by others who witnessed the entire test procedure that the engine was pulled out of outdoor storage where it lay unprotected against the elements. Before it was placed on the launch stand, the test crew dusted off the desert sand that had clung to it. This unplanned inlcusion [sic] of a bit of an environmental test also demonstrated hardware ruggedness of the kind no other liquid rocket eingine [sic] could approach."
The Surveyor program managed to make it "just work" 5 out of 7 times by adopting this approach. It had robust landing legs and RADAR. They would decelerate and then shut off the engine 11' above the surface. The wide, sturdy legs would then absorb that final impact of coming stand still from free fall.
These programs had a lot of capital behind them. Some components required precision engineering, but there's a very clear through line and embrace of the "we gotta make stuff that can take a lickin' & keeps kickin'" philosophy.
Modern engineering approaches seem to be the opposite of that. I think we've become so accustomed to living in a silicon driven world where our personal devices are engineered at microscopic level that we've forgotten how to do things the Apollo-era way.
For example, to the best of my knowledge, IM-2 doesn't use RADAR — they're using LIDAR and optical navigation instead. Perhaps it is to save on mass and power so that more payload reaches the surface. Perhaps optical navigation was declared to be "good enough." Perhaps it doesn't make sense from a minmaxing of capital perspective. But this philosophy may not be suited to an untamed frontier.
China adopted the Surveyor / Apollo-era philosophy. Their first successful lander, Chang'e 3, used the same hover & fall technique as Surveyor.
> The vehicle will hover at this altitude, moving horizontally under its own guidance to avoid obstacles, and then slowly descend to 4 m above the ground, at which point its engine will shut down for a free-fall onto the lunar surface. The landing site will be at Sinus Iridum, at a latitude of 44º.
It chose the terminal landing sites with the help of LIDAR and its cameras, but it relied on RADAR and a suite of sensors to have robust navigation.
The follow up missions up-ed the ante every time, but they seem to have consistently focused on the robustness of their craft over precision, MBA-spreadsheet-oriented minmax-ing.
> "I think we've become so accustomed to living in a silicon driven world where our personal devices are engineered at microscopic level that we've forgotten how to do things the Apollo-era way."
This is a really interesting point. I think a practical issue in modern times as well is that companies are being inspired by SpaceX while forgetting that it took SpaceX alot of work to get to the point of being able to do things like casually land a 20 story tower in the middle of the ocean on a barge, let alone the even more ridiculous 'stunts' they're doing with Starship.
Apollo was starting from the perspective of trying to do something where it was even debatable about whether it was possible. And so I think there was a lot more 'humility' in design, for lack of a better word.
You're criticizing the prioritization of cost, not the concept of trying to solve for constraints. Engineering is about constrained optimization to meet customer needs.[1] Learning this is a core part of the curriculum at my accredited engineering school.
> Engineering design is a process of making informed decisions to creatively devise products, systems, components, or processes to meet specified goals
based on engineering analysis and judgement. The process is often
characterized as complex, open-ended, iterative, and multidisciplinary.
Solutions incorporate natural sciences, mathematics, and engineering
science, using systematic and current best practices to satisfy defined
objectives within identified requirements, criteria and constraints.
> Constraints to be considered may include (but are not limited to): health and
safety, sustainability, environmental, ethical, security, economic, aesthetics
and human factors, feasibility and compliance with regulatory aspects, along
with universal design issues such as societal, cultural and diversification
facets.
It's not an MBA philosophy but is intrinsic to the profession. Apollo didn't go up because of vibes, it went up because engineers knew the goals going in and to figured out how much fuel was needed to go to the moon. It also went up because the United States was willing to spend over a quarter of a trillion dollars (adjusted for inflation) on getting there,[2] and ignored the arguments that it was a giant waste of money while there were social problems at home.[3]
This comment isn't directed at you jjmarr, I appreciate your take, but I think it's important to point out that,
> constrained optimization to meet customer needs
is MBA-capture in action.
For most of its existence as a formal field, engineering wasn't about making geegaws that "meet customer needs." It was about building stuff that matters. Houses that didn't collapse. Roads and machines that made it possible to traverse vast distances. Toys that delighted us. Aquaducts that delivered clean water. Drainage that helped remove muck. Plumbing that cleaned our cities. Threshers that helped us harvest crops. Lights that vanquished the dark.
The story of engineering is the story of creating technology that helps alleviate want.
You can say that there was a "customer" for each, which is great and all, but that's not why we did it. We did it so that we could move out of the caves and not be in filth and muck all the time.
We did it because it felt good. And we did it because it was the right thing to do.
I don't understand what you are objecting to. Is it just the phrasing that's bothering you? Because from my point of view, "houses that don't collapse" and "machines that can travel vast distances" are all formulations of customer needs. And dealing with contraints is pretty much engineering 101, every project is at the very least constrained on two of these axes: cost, construction time or material availability.
I was watching this documentary Happy People, about people who live in the Siberian Taiga (by Werner Herzog, would highly recommend). A man is talking about making a new set of skis, and it shows the incredibly long and careful process of selecting the perfect trees, chopping them down in the right way, treating the wood and so on. He mentions how mass manufactured skis are light and cheap and will work fine for a while, but when one breaks and you're in the Siberian wilderness you can't just go to the store for a replacement. That really stuck with me.
1960s US is hardly Siberia and I don't think any NASA engineers had their heads on the chopping block if their designs failed. But engineering philosophy was still rooted in survival; the primary goal was to make something that wouldn't kill you because it fails.
You hear stories about artisans in the old days refusing work because they don't believe what they're being asked to make is safe or reliable enough for the person asking for it. Maybe it's romanticized and idealized, maybe it's just them covering their ass so they don't get blamed. But that philosophy of personal responsibility not just for making things according to the constraints, but for the outcome too, is something that served society well for a long time before slowly disappearing over the past century or so.
It hasn't left without reason. As the things being made became less key to survival and more key to thrival, as the world became more interconnected and safe, it didn't make as much sense. Just think of how many crazy, inventive concepts we use every day wouldn't have been made if they could only be made to work reliably! Our entire modern existence is based off things that don't work reliably. It's a blessing and a curse.
But when we're exploring the final frontier we need frontier thinking and frontier technology; things that, from the ground up, are built to work first with all other constraints secondary. Unfortunately spaceflight endeavors today must invariably build off the 'good enough, when it breaks just make a new one' foundation that permeates modern design at every level. Even if you want to make something nowadays with the sole purpose of working, as long as you're using any technological advancements made in the past 50 years chances are you're using something that wasn't made with that goal in mind.
I think you are presenting a romanticized fictional narrative, especially when it comes to aerospace.
When engineers were working on Apollo and lunar landers, they were working on a set of customer requirements a mile long. Roving tinkerers didn't build the moon rockets. Engineers spent countless hours in design reviews with the customer, in this case, NASA.
Roman engineers didn't build aqueducts and colosseums on a lark, or some sense of poetic destiny.
> If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering.
I wonder how much of that is because of public attitudes to government spend. Like if a SpaceX rocket blows up, they're taking innovative, risk-taking approaches to rocket development. If a NASA rocket blows up they're wasting tax payer funding.
Similarly the pressure on NASA to have fewer programs for cost saving is similar. If NASA has two rocket programs, one of which is at a "good enough" level for launching satellites economically into space and one of them is a "safety conscious" rocket for manned launches at a higher per-mission cost, then people look at this and think why is NASA duplicating work and spending. So now they get only one program, so then even launching a GPS satellite is the expensive, human-safe rocket.
> China adopted the Surveyor / Apollo-era philosophy. Their first successful lander, Chang'e 3, used the same hover & fall technique as Surveyor.
Dropping the last 4 metres isn't a sign of having a ruggedized, over-speced "takes a lickin' and keeps on kicking' approach". In lunar gravity, you could drop a raw egg from that height and not perturb the chick inside.
Instead the aim is to avoid throwing up too much moon dust with retro rockets.
Luna 9 (1966) really did need to withstand a bit of a bump, but it was 22km/h, comparable with a fast running pace or a car in first gear, not a high speed impact.
This reads like a “comment” version of Destin’s speech to a NASA group a few years ago [0]. The loss of institutional knowledge and fundamentals philosophical differences seem like they’ll need to be overcome.
The talk was to the American Astronautical Society, not specifically a NASA group. But Destin talked as though he imagined everyone in the audience worked at NASA. It actually bothered me a bit - if I had been at that talk I would have been a bit pissed off, because he was basically using it as a channel to talk to people who probably weren't actually even there.
> Perhaps it is to save on mass and power so that more payload reaches the surface.
It doesn't matter how much mass was saved and how much more payload that allowed to reach the surface if the landing isn't successful. Successful landing is mandatory for anything else to matter. The obviousness of this baffles me that it is taken so haphazardly.
I believe that the thing you are missing is Intuitive Machines aims at landing a lot of spacecrafts, not just one. They hope to have a limited number of failures to land which will teach them how to do it reliably. We might doubt will this work or not, but if we accept the plan then it becomes a rational decision to increase the engineering complexity and risks of failure by saving on mass, because in the long run less missions will allow to land more payload.
Though, of course, I wonder how many landings they are planning to do, and how many of them they need to do to compensate for each failure to land.
Again, if you can't stick the landing, you might as well not have any payload on it. So if you're worried about cost, keep testing until you can stick the landing with dummy mass. Once that works, send the real payload. Otherwise, you're just wasting payload.
The mindset difference seems to be that if there's no human on board, so no problemo wasting a lander if something goes wrong. That's just a bad attitude (as well as yaw and roll). If you designed everything with "baby on board" hanging in the window, you'd probably not cut so many corners so sharply. Otherwise, why not just light your cigars with hundred dollar bills. How would you feel if you were on the team building the payload, but the lander guys keep fucking up so you just wasted however much time you spent because "meh, we're just testing". In sports, there's a saying "practice like you play because you play like you practice".
Who said it was easy? I'm saying they are not giving it enough respect because of the attitude of "it's only a test". That's bad. It's still expensive to get to that point. They have become complacent/lazy with the luxury of being able to iterate. Rather than spending money on engineering testing, they just build "real things" that don't work and improve the failed things. Never mind that if procedure 10 failed, you never get to test procedure 11+. So your next launch fails at procedure 11. It's just a bad attitude.
At what point do you just fire your entire "Land on Moon" software team, and hire a couple young Neil Armstrong wanna-be's, who can hand-land your spacecraft remotely? (In spite of the moon-earth-moon signal lag.)
I mean, because it's in the dark I'd expect it to reach equilibrium with space background thermal radiation which is around 3K. Yet its 100K. Where does that heat comes from? It radiates from earth? Conduct through the floor coming from the inner of the moon itself? (Is there some kind of geothermal gradient on the moon BTW?)
I refuse to believe anyone knows how cold -280F is.
When you have such extreme temperatures you think in Kelvin or at least Celsius.
Wow. Cosmic resonance man...
Here's the hole it fell into:
https://www.lroc.asu.edu/images/1408
Related. Others?
Athena spacecraft declared dead after toppling over on moon - https://news.ycombinator.com/item?id=43292471 - March 2025 (340 comments)
The Moon Lander Athena's Fate on the Lunar Surface Is Uncertain - https://news.ycombinator.com/item?id=43283136 - March 2025 (1 comment)
I know I'm a snob... but I can't read science news using the imperial system.
Everyone knows feet and British stones is the way to measure things in space. Just ask any scientician:
https://m.youtube.com/watch?v=nRnt3TE-V-Y
Well, the definition of 0ºC is based on the freezing point of water at one atmosphere of pressure, which isn't super relevant on the Moon. You could give it in K but that's not very relatable.
-280F, -173C, or 100K is not relatable to anyone except niche researchers. Maybe slap in the extra few people who happen to work with liquid helium and you are still talking about 0% of the population.
You would think either they could parameterise all units or a plausible browser extension could convert elephants to swimmingpools and King's thumbs to badly measured fractions of a diameter.
> 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.
Oh yeah, we've all Kerbaled it in like that at one point or another.
Still unclear what happened. Did they not anticipate a big moon hole or did navigation fail when the rangefinder failed?
Scott Manley has a great video explaining what he thinks happened. https://youtu.be/ISZTTEtHcTg?si=0LZFyiCysBiFZrMz
Scott Manley and I agree that altitude signal shouldn't matter if navigation is correct. Athena simply risked touchdown, and it didn't find a flat spot, it found a hole.
https://youtu.be/ISZTTEtHcTg&t=1158
Can you quote the bit you think is relevant here?
He's saying modern spacecraft can null out the horizontal velocity to land, but without an altimeter, you don't necessarily know when to do so, nor when to give the thrusters a little boost to avoid an obstacle you're about to hit, like a plateau.
I'm not sure what you find unclear. Navigation was fine - "Athena knew where it was relative to the surface of the Moon" - but without a working altimeter it was kinda fucked for actually touching down.
Hard landing, skid, tip.
The top-heavy design didn't help things either. I'll be shocked if they don't go three-for-three on landing sideways given IM3 has the same tall design.
The company claims it's not as top-heavy as you'd think from pics:
https://www.theregister.com/2025/03/07/intuitive_machines_la...
> At his press conference earlier today, Altemus defended the design, saying the spacecraft doesn’t have a high center of gravity because most of its cargo attaches to the base of the vehicle. He said there were no plans for a radical rethink of his company's design.
(We see this in returning F9 first stages, as well.)
Why do people keep thinking this thing is top heavy just because its taller than wide?
The heavy bits are at the bottom.
> Why do people keep thinking this thing is top heavy just because its taller than wide?
Because it keeps falling over?
The landing leg broke. How does that show you its top heavy?
>> The top-heavy design didn't help things either
Just wait for SpaceX to start trying to land starships on the moon. Also vertically. Also doomed to tip over whenever the surface is slightly out of spec.
https://www.spacex.com/humanspaceflight/moon/
> Just wait for SpaceX to start trying to land starships on the moon. Also vertically
SpaceX has done it. To date, other nation-states have tried and failed to replicate their achievements in this domain.
IM’s design is wrongly optimised and probably requires a rethink. That the CEO won’t contemplate this isn’t a great sign for the company.
Lol. SpaceX has landed on prepared surfaces, concrete pads on land or on large barges. They literally have a big X to mark the target. Let's see them land on some random beach. But that is still peanuts comparted to the moon's surface.
SpaceX has done it.
SpaceX has landed Starship on the moon?!
SpaceX has repeatedly and reliably landed vertical stacks. On any body. Out of the engineering problems inherent to HLS, sticking the landing isn’t material because for them, for that team, it isn't as novel a problem as e.g. in-orbit refuelling or getting Raptors to relight on the Moon.
Put another way, just because SpaceX has done it doesn't mean the same problem carries the same risk for a team like IM's.
If navigation was fine, why was touchdown on a plateau?
Because "where am I" and "how high am I over that position" are very different things.
Visual demonstration of being at the wrong altitude in the right spot: https://www.f-16.net/f-16-news-article968.html
Was there no functioning laser or radar altimeter for the final descent phase?
"However, the lander's altimeter had failed."
Looking at this closely, it was working, however it was noisy. I speculate that they didn't correctly anticipate the moon dust problem. Laser rangefinders may not be a workable solution for future landings.
https://arstechnica.com/space/2025/03/intuitive-machines-sec...https://www.space.com/nasa-moon-landing-dust-concerns.html
https://en.wikipedia.org/wiki/Lunar_horizon_glow
Noise at 30km altitude probably points more towards a sensor issue than dust.
-173°C.
100K
This actually puts it into perspective, knowing it's closer to absolute zero than room temperature.
It’s roughly a third of room temperature.
Which is hard to grok since a third of something warm doesn't seem to be extremely cold.
Exactly, the Kelvin unit makes it easy to see that. I can't believe they used fucking Fahrenheit in the title.
"You know how hot you feel when you're running a fever? Well, it was nearly three times that cold!"
https://en.wikipedia.org/wiki/IM-2
Dumb question, but why can't it have a few simple telescopic sticks which extend to flip it over if it lands upside down.
Seems it's the second time they fail in this mode.
Definitely not a dumb question. The first lander to land on the Moon (after many failures) is pretty amusing. [1] The Soviets a designed a lander that'd be launched right into the Moon but, just before impact would jettison the lander which itself was a highly reinforced ball that was then designed to simply pound into the Moon at 54kph, but survive the crash. The egg then unfurled and finally humanity had achieved a 'soft' landing on the Moon. Somehow it kind of makes one think of a really elaborate egg drop contest paired with a 'what happens if you jump right before the elevator crashes.'
Like another comment mentioned, complexity and size are big issues. Some more are power/mechanics (fluids, such as for hydraulics, and -280F aren't gonna play well together) and then there's the fact that there's not even a guarantee it'd work. Your legs could get damaged, you might end up in an orientation where none of the legs are appropriate, and so on. So you may be adding a whole bunch of complexity for stuff that might not even save you in the situation it was designed for!
[1] - https://en.wikipedia.org/wiki/Luna_9
Moe parts, more complexity, more weight.
Mass. Each kilogram costs what, millions? Hundreds of millions?
There's a small chance that navigation or landing fails in a way that would make those legs useful, and an even smaller chance that they'll save the mission.
Given tight budgets, this is almost certainly not a gamble worth taking
NASA paid $65M for the launch. It's about 2,000 kilos.
$32k/kilo or so.
battlebots did it first!
Because: 1. It cannot fail in this mode. 2. Testing is done by the user, test results are sent by telemetry and the fix will be done, when the bug can be reproduced on developer's computers.
/s
How about a parachute to keep it the right way up?
Not enough of an atmosphere.
Kinda explain why Neil Armstrong burned up all their fuel except for a few seconds scoping out the landing site in paranoia.
Instead of building all these expensive to launch big landers, why not get some pizza-box sized probes into earth orbit AND THEN do like a slo-mo golf shot arcing to where the moon will be for a super slow/soft landing?
Some will fail but if you launch 100 and get 20-30 working, there you go.
As technology progresses, get it down to a shoe-box sized probe and then in 10 years smartphone sized (in 100 years tic-tac sized).
Space applications of all sorts are screaming out for mass production approaches. With so much design work and verification the actual manufacturing cost tends to be trivial by comparison, the work readily adapted to concurrent manufacturing processes.
When I signed on to a Mars mission in 1999, the scientists told me that’s JPL’s approach: instead of extremely expensive, robust, redundant craft, they would begin to make leaner stuff and worry less when it failed...
Around the same time, Mission Control was replacing their bespoke hardware with COTS and trying to minimize the “glue” HW/SW for space systems.
You'll also see that expertise on a particular instrument package is leveraged over and over across multiple missions.
NASA still has amazing educational outreach and makes incredible software, even for mere mortals.
Combine that with leaving the long-range comms (and higher-powered equipment) in lunar orbit as the "master" for all the probes scattered on the surface, and maybe the problem becomes simpler by breaking it in two.
It's definitely possible to target a certain surface location on the moon from low Earth orbit and set off on a trajectory to get there with a single burn. However, as the craft(s) approach the moon and enter its sphere of influence, gravity will kick in and increase their relative velocity to the surface. Another burn (suicide burn if you're feeling lucky) would be needed for the soft touchdown.
The moon is also gravitationally very "lumpy", so some small corrections might be needed along the way as well.
If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering.
Robert Truax, the designer of the Sea Dragon, loved to promote the design paradigm of Big Dumb Boosters. Instead of many small, sophisticated rocket engines, what if we made one big robust one that can take a lickin' and keep on kickin'.
The idea was to relax the mass margins and to create big. dumb. boosters. It's the approach TRW explicitly followed for the Lunar Module engine,
The Surveyor program managed to make it "just work" 5 out of 7 times by adopting this approach. It had robust landing legs and RADAR. They would decelerate and then shut off the engine 11' above the surface. The wide, sturdy legs would then absorb that final impact of coming stand still from free fall.These programs had a lot of capital behind them. Some components required precision engineering, but there's a very clear through line and embrace of the "we gotta make stuff that can take a lickin' & keeps kickin'" philosophy.
Modern engineering approaches seem to be the opposite of that. I think we've become so accustomed to living in a silicon driven world where our personal devices are engineered at microscopic level that we've forgotten how to do things the Apollo-era way.
For example, to the best of my knowledge, IM-2 doesn't use RADAR — they're using LIDAR and optical navigation instead. Perhaps it is to save on mass and power so that more payload reaches the surface. Perhaps optical navigation was declared to be "good enough." Perhaps it doesn't make sense from a minmaxing of capital perspective. But this philosophy may not be suited to an untamed frontier.
China adopted the Surveyor / Apollo-era philosophy. Their first successful lander, Chang'e 3, used the same hover & fall technique as Surveyor.
It chose the terminal landing sites with the help of LIDAR and its cameras, but it relied on RADAR and a suite of sensors to have robust navigation.The follow up missions up-ed the ante every time, but they seem to have consistently focused on the robustness of their craft over precision, MBA-spreadsheet-oriented minmax-ing.
> "I think we've become so accustomed to living in a silicon driven world where our personal devices are engineered at microscopic level that we've forgotten how to do things the Apollo-era way."
This is a really interesting point. I think a practical issue in modern times as well is that companies are being inspired by SpaceX while forgetting that it took SpaceX alot of work to get to the point of being able to do things like casually land a 20 story tower in the middle of the ocean on a barge, let alone the even more ridiculous 'stunts' they're doing with Starship.
Apollo was starting from the perspective of trying to do something where it was even debatable about whether it was possible. And so I think there was a lot more 'humility' in design, for lack of a better word.
You're criticizing the prioritization of cost, not the concept of trying to solve for constraints. Engineering is about constrained optimization to meet customer needs.[1] Learning this is a core part of the curriculum at my accredited engineering school.
> Engineering design is a process of making informed decisions to creatively devise products, systems, components, or processes to meet specified goals based on engineering analysis and judgement. The process is often characterized as complex, open-ended, iterative, and multidisciplinary. Solutions incorporate natural sciences, mathematics, and engineering science, using systematic and current best practices to satisfy defined objectives within identified requirements, criteria and constraints.
> Constraints to be considered may include (but are not limited to): health and safety, sustainability, environmental, ethical, security, economic, aesthetics and human factors, feasibility and compliance with regulatory aspects, along with universal design issues such as societal, cultural and diversification facets.
It's not an MBA philosophy but is intrinsic to the profession. Apollo didn't go up because of vibes, it went up because engineers knew the goals going in and to figured out how much fuel was needed to go to the moon. It also went up because the United States was willing to spend over a quarter of a trillion dollars (adjusted for inflation) on getting there,[2] and ignored the arguments that it was a giant waste of money while there were social problems at home.[3]
[1]https://egad.engineering.queensu.ca/wp-content/uploads/2023/...
[2] https://www.planetary.org/space-policy/cost-of-apollo
[3] https://en.wikipedia.org/wiki/Whitey_on_the_Moon
This comment isn't directed at you jjmarr, I appreciate your take, but I think it's important to point out that,
is MBA-capture in action.For most of its existence as a formal field, engineering wasn't about making geegaws that "meet customer needs." It was about building stuff that matters. Houses that didn't collapse. Roads and machines that made it possible to traverse vast distances. Toys that delighted us. Aquaducts that delivered clean water. Drainage that helped remove muck. Plumbing that cleaned our cities. Threshers that helped us harvest crops. Lights that vanquished the dark.
The story of engineering is the story of creating technology that helps alleviate want.
You can say that there was a "customer" for each, which is great and all, but that's not why we did it. We did it so that we could move out of the caves and not be in filth and muck all the time.
We did it because it felt good. And we did it because it was the right thing to do.
I don't understand what you are objecting to. Is it just the phrasing that's bothering you? Because from my point of view, "houses that don't collapse" and "machines that can travel vast distances" are all formulations of customer needs. And dealing with contraints is pretty much engineering 101, every project is at the very least constrained on two of these axes: cost, construction time or material availability.
> stuff that matters
Matters to whom?
Answer: that's the definition of a customer in an engineering project
Matters how / why?
Answer: those are the requirements / user stories.
Helping people by doing engineering feels good and is the right thing to do, but formalizing this process a bit does not detract from it.
I was watching this documentary Happy People, about people who live in the Siberian Taiga (by Werner Herzog, would highly recommend). A man is talking about making a new set of skis, and it shows the incredibly long and careful process of selecting the perfect trees, chopping them down in the right way, treating the wood and so on. He mentions how mass manufactured skis are light and cheap and will work fine for a while, but when one breaks and you're in the Siberian wilderness you can't just go to the store for a replacement. That really stuck with me.
1960s US is hardly Siberia and I don't think any NASA engineers had their heads on the chopping block if their designs failed. But engineering philosophy was still rooted in survival; the primary goal was to make something that wouldn't kill you because it fails.
You hear stories about artisans in the old days refusing work because they don't believe what they're being asked to make is safe or reliable enough for the person asking for it. Maybe it's romanticized and idealized, maybe it's just them covering their ass so they don't get blamed. But that philosophy of personal responsibility not just for making things according to the constraints, but for the outcome too, is something that served society well for a long time before slowly disappearing over the past century or so.
It hasn't left without reason. As the things being made became less key to survival and more key to thrival, as the world became more interconnected and safe, it didn't make as much sense. Just think of how many crazy, inventive concepts we use every day wouldn't have been made if they could only be made to work reliably! Our entire modern existence is based off things that don't work reliably. It's a blessing and a curse.
But when we're exploring the final frontier we need frontier thinking and frontier technology; things that, from the ground up, are built to work first with all other constraints secondary. Unfortunately spaceflight endeavors today must invariably build off the 'good enough, when it breaks just make a new one' foundation that permeates modern design at every level. Even if you want to make something nowadays with the sole purpose of working, as long as you're using any technological advancements made in the past 50 years chances are you're using something that wasn't made with that goal in mind.
I think you are presenting a romanticized fictional narrative, especially when it comes to aerospace.
When engineers were working on Apollo and lunar landers, they were working on a set of customer requirements a mile long. Roving tinkerers didn't build the moon rockets. Engineers spent countless hours in design reviews with the customer, in this case, NASA.
Roman engineers didn't build aqueducts and colosseums on a lark, or some sense of poetic destiny.
The constrained optimization part is good, though.
> If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering.
I wonder how much of that is because of public attitudes to government spend. Like if a SpaceX rocket blows up, they're taking innovative, risk-taking approaches to rocket development. If a NASA rocket blows up they're wasting tax payer funding.
Similarly the pressure on NASA to have fewer programs for cost saving is similar. If NASA has two rocket programs, one of which is at a "good enough" level for launching satellites economically into space and one of them is a "safety conscious" rocket for manned launches at a higher per-mission cost, then people look at this and think why is NASA duplicating work and spending. So now they get only one program, so then even launching a GPS satellite is the expensive, human-safe rocket.
> China adopted the Surveyor / Apollo-era philosophy. Their first successful lander, Chang'e 3, used the same hover & fall technique as Surveyor.
Dropping the last 4 metres isn't a sign of having a ruggedized, over-speced "takes a lickin' and keeps on kicking' approach". In lunar gravity, you could drop a raw egg from that height and not perturb the chick inside.
Instead the aim is to avoid throwing up too much moon dust with retro rockets.
Luna 9 (1966) really did need to withstand a bit of a bump, but it was 22km/h, comparable with a fast running pace or a car in first gear, not a high speed impact.
This reads like a “comment” version of Destin’s speech to a NASA group a few years ago [0]. The loss of institutional knowledge and fundamentals philosophical differences seem like they’ll need to be overcome.
[0] https://youtu.be/OoJsPvmFixU?si=EUxpp6C9vRAYD3kA
The talk was to the American Astronautical Society, not specifically a NASA group. But Destin talked as though he imagined everyone in the audience worked at NASA. It actually bothered me a bit - if I had been at that talk I would have been a bit pissed off, because he was basically using it as a channel to talk to people who probably weren't actually even there.
Just youtubers doing youtube things, I guess.
What an absolutely phenomenal speech and video. Just a sort of +1 highly recommended thing. That video was crazy insightful.
> Perhaps it is to save on mass and power so that more payload reaches the surface.
It doesn't matter how much mass was saved and how much more payload that allowed to reach the surface if the landing isn't successful. Successful landing is mandatory for anything else to matter. The obviousness of this baffles me that it is taken so haphazardly.
I believe that the thing you are missing is Intuitive Machines aims at landing a lot of spacecrafts, not just one. They hope to have a limited number of failures to land which will teach them how to do it reliably. We might doubt will this work or not, but if we accept the plan then it becomes a rational decision to increase the engineering complexity and risks of failure by saving on mass, because in the long run less missions will allow to land more payload.
Though, of course, I wonder how many landings they are planning to do, and how many of them they need to do to compensate for each failure to land.
Again, if you can't stick the landing, you might as well not have any payload on it. So if you're worried about cost, keep testing until you can stick the landing with dummy mass. Once that works, send the real payload. Otherwise, you're just wasting payload.
The mindset difference seems to be that if there's no human on board, so no problemo wasting a lander if something goes wrong. That's just a bad attitude (as well as yaw and roll). If you designed everything with "baby on board" hanging in the window, you'd probably not cut so many corners so sharply. Otherwise, why not just light your cigars with hundred dollar bills. How would you feel if you were on the team building the payload, but the lander guys keep fucking up so you just wasted however much time you spent because "meh, we're just testing". In sports, there's a saying "practice like you play because you play like you practice".
Okay but successfully landing an inanimate carbon rod is easy, but why?
Who said it was easy? I'm saying they are not giving it enough respect because of the attitude of "it's only a test". That's bad. It's still expensive to get to that point. They have become complacent/lazy with the luxury of being able to iterate. Rather than spending money on engineering testing, they just build "real things" that don't work and improve the failed things. Never mind that if procedure 10 failed, you never get to test procedure 11+. So your next launch fails at procedure 11. It's just a bad attitude.
To a point. Landing a solid brick of aluminum isn't much good, unless the entire goal of the exercise is to get a successful landing of something.
>It chose the terminal landing sites with the help of LIDAR and its cameras, but it relied on RADAR and a suite of sensors to have robust navigation.
I think this is the smoking gun. RADAR is usually successful, while LIDAR has a poor record.
At what point do you just fire your entire "Land on Moon" software team, and hire a couple young Neil Armstrong wanna-be's, who can hand-land your spacecraft remotely? (In spite of the moon-earth-moon signal lag.)
Can someone ELI5 why it's at that temperature?
I mean, because it's in the dark I'd expect it to reach equilibrium with space background thermal radiation which is around 3K. Yet its 100K. Where does that heat comes from? It radiates from earth? Conduct through the floor coming from the inner of the moon itself? (Is there some kind of geothermal gradient on the moon BTW?)