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Comment by nine_k | Hacker News Reader

One similarly structured craft (thin and tall) reached the Moon a year ago, and also eventually toppled.

Maybe next missions will feature less tower-shaped designs and more crab-shaped designs, at least during the landing phase.

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Which gives me great amusement about the current human spaceflight plan to land upright Starship on the moon, and lower astronauts from the top of what is effectively a tower-like 13-story building (52.1m without landing legs, at 9m tube width) using some kind of elevator solution. To put things into perspective, this is roughly the same height as the Leaning Tower of Pisa, and with landing legs extended probably about the same width as well.

https://en.wikipedia.org/wiki/Starship_HLS#/media/File:HLS_S...

https://www.nasa.gov/image-article/nasa-astronauts-test-spac...

Sure, there's lots of details to consider, e.g. center of gravity, overall weight, maximum possible duration to hover and ability to accurately steer and pick your landing spot. But the inherent difficulty in "how do you not topple over" is definitely there, and it's clear the proposed Starship lander will have to outperform these IM landers significantly.

That said, if you want to scale out payload to the surface I guess you have to (which however eats into your center of gravity advantages from having lots of engines at the bottom, too).

At least they're likely to do unmanned test landings until they successfully land upright. But it seems nobody followed the design of the appollo lander, except the Blue ghost which landed successfully last week.

If they can control the angle of each leg with enough precision, that might be enough to compensate for (slightly) uneven terrain.

I understand that the recently successful Blue Ghost has sensors to detect suitability of the landing spot, and used it to re-position twice while landing. Starship would probably need something like that, too.

with enough energy(like starship would have), i suppose you could get out of an irrecoverable tipping over motion by just lighting the engines and trying again. Before you fall, obviously. "works in KSP"^TM

> how do you not topple over

Projectile grappling-hooks to embed into nearby ground then winch the line taught? Just have to make sure all are launched at the same time with force vectors that cancel out. Maybe even launch them before touchdown so it doesn't topple over during landing if one of the feet land on a random rock.

My vote is for a large BattleBots style flipper that they flop their rover around with until it falls in their preferred orientation.

Just don't land too close to where the house robots are...

Could you land a weeble? So it wobbles and does not fall down.

I saw this episode of For All Mankind! It didn't seem to end well

I wonder what height you can safely jump from onto the moons surface?

Probably around 12 meters (40 feet or so?). That would be like falling 2 m (6 feet) on earth, which isn’t very safe but pretty doable. Maybe 8 meters to make it more safe?

That’s based on impact speed.

Probably less than that. Consider your suit needs to survive without a tear.

Oh I guess the suit is going to prevent you doing a parcour roll!

Starship is simply due to the desire to have a Sci-Fi looking ship land on a planet. It’s not being done for practical reasons. It’s being done because it looks cool.

To learn more about the strategy for landing on the moon, listen to this audiobook. Extremely good.

The Man Who Knew the Way to the Moon

hey the leaning tower of pisa is still standing, clearly this precedent means that starship HLS will be stable

The craft that tipped over last year (Odysseus) was also made by Intuitive Machines (IM).

Firefly's Blue Ghost landed on the moon last week without tipping over, proving that a modern commercial company can do it.

Kind of embarrassing for IM which is 0 for 2. I'm sure there are all kinds of reasons/excuses for why IM's landers fell over and I'm sure their mission profiles are different from Firefly's, but from a high level perspective I'm sure senior leaders at NASA are reconsidering giving any new contracts to IM.

Yeah, was cool to see Blue Ghost be successful. And do the point about tall and thin, the Blue Ghost lander is much more squat than the Intuitive Machines landers

https://fireflyspace.com/blue-ghost/

> craft that tipped over last year (Odysseus) was also made by Intuitive Machines (IM)

Have they published a root-cause analysis?

Apparently last time their laser rangefinder was turned off groundside and thus wasn’t available during landing.

This time they remembered to turn it on, but it didn’t work very well.

That’s a proximate-cause analysis. If the root of their problem is a rangefinder, what happened that caused them to consistently miss with it?

The lack of credible comments strikes me as someone socking the answer: they’ve committed to a stacked format that is inherently unstable. If they can’t get an answer out before the next budget is passed, their contracts should be cancelled.

I'm sure they're accounting for dust, but using a laser in an environment that kicks up a ton of dust just doesn't seem like a great idea.

> Firefly's Blue Ghost landed on the moon last week without tipping over

> from a high level perspective I'm sure senior leaders at NASA are reconsidering giving any new contracts to IM.

Truth is, all contractors rely on NASA data about Moon surface, and this data is not 100% reliable.

But some people trust NASA and others much more cautious and include bigger possible error margins in their models.

I mean, FF could just include much larger design margins, with less payload, so next time FF will optimize design and could also tip over.

But good news, IM next time could make larger margins and will also achieve 100% success.

> I'm sure senior leaders at NASA are reconsidering giving any new contracts to IM.

at NASA, and DOGE, when they catch wind of it

bagholders on reddit trying to understand the 50% drop have not been open to anything rational that explains the 50% drop

so far I've gotten "You are blinded by dumb hate." for pointing out that $LUNR's unintuitive machines getting contracts from Nasa are their only business plan, as if this is a partisan thing

Shit, NASA does space stuff, it fails sometimes! Do we want to only fund things we know to be 100% easy to do? And don't fucking tell me, "we already landed on the moon once, how hard can it be?" because this shit is really fucking hard and takes lots of cash and a lot of what apppears to be "waste" or "failure" on a first order approximation, but in reality is actually "learned knowledge".

I can't believe people think they're going to "make america great again" by cutting funding for all the stuff that makes America an economic, cultural, and academic powerhouse.

Worse, it’s richest country on earth complaining about being too poor and having to enact austerity measures — implemented by the richest person on the planet who’s personal pay is much, much higher than any of the savings he’s found so far.

I’ve seen many occasions in my career when some manager had flown across the country with a business class ticket, stayed in a fancy hotel, rented a luxury car, and turned up to an all-hands-on-deck meeting to announce in a grave tone that the minimum wage workers are just going to have to make some sacrifices.

This is almost precisely what’s going on with DOGE except you can substitute private jet and secret service motorcade. And instead of minimum wage, it’s… less than minimum wage.

The richest are complaining about being too poor to help the needy, and fixing the issue by cutting every program that helps those under the poverty line.

Well, basically, that sums it all up.

This doesn't seem a fair analogy. Elon Musk is not being paid by the government, as I understand.

The reason the manager flying around spending money to attend a downsizing meeting is gross is that the manager is spending company money (that could go to prevent downsizing).

To complete the analogy, you would need to be implying that Elon's personal money should be paid to fund federal services.

> you would need to be implying that Elon's personal money should be paid to fund federal services.

I am. These payments are called taxes.

Taxes he's successfully evaded paying using the the same tricks as every other billionaire, such as taking out loans against his shares that will be repaid after his death by his estate, which has negligible tax rates compared to the kind of income taxes paid by mere mortals.

All joking aside, if Elon -- just him, no other billionaire -- had simply paid the same marginal tax rates as any random upper-middle-class citizen, it would be 10x the amount DOGE had cut so far from the federal budget.

>Elon Musk is not being paid by the government, as I understand.

https://www.inc.com/bruce-crumley/why-elon-musks-faa-contrac...

https://www.nytimes.com/2025/02/11/us/politics/elon-musk-com...

https://www.washingtonpost.com/business/2025/03/01/elon-musk...

https://www.banking.senate.gov/newsroom/minority/as-elon-mus...

https://apnews.com/article/house-democrats-musk-doge-oversig...

I totally agree with the space is hard, it fails sometimes. I been in the space industry on both the super rigorous high cost, high mission assurance side of things and the low cost commercial launch 10 and hopefully most of them work side of things. The lunar lander is an ambitious first project and two failures in a row is real rough, but definitely happens the space industry in new ventures. I'm sure there are great engineers there and what they are doing is tough.

But...specifically on funding for Intuitive Machines I don't understand how NASA also gave then an IDIQ contract for up to $4.8 billion for lunar communications and PNT services [0] based on the experience of one lunar lander that didn't actually work.

[0] https://spacenews.com/nasa-selects-intuitive-machines-for-lu...

They shouldn't just cancel, but with the same kind of failure twice in a row it seems they should require correcting the tipping-over issue before trying a third time.

Once upon a time a bunch of nerds failed 3 times in a row while launching small rockets from an atoll. Some 20 years later they are now 13k+ nerds, they're launching every other day, land their boosters and are slowly becoming an ISP with a rocket launching side business.

Space is hard. There's nothing "embarrassing" in controlled landing on the freakin Moon with a shoestring budget, even if the landers fell over. Reddit's r/technology is leaking in this thread.

> Once upon a time a bunch of nerds failed 3 times in a row while launching small rockets from an atoll

Once upon a time most planes crashed. Then the state of the art advanced.

If IM can’t publish a convincing root-cause analysis for why their landers keep tipping over while their competitors’ don’t, they shouldn’t get new contracts and existing ones should be revisited.

I thought the same, but ...

1) private companies landing on the moon is a brand new thing in a very difficult technology. If we want to encourage it, maybe we should minimize risk.

2) what were their mission goals? Maybe it was just to stick the landing, test landing gear, etc. (There is a bunch of equipment on there for other things, so they must have had some other plans.)

3) what is the difference between a private company and NASA doing it? That is, why is it so hard to do what NASA did over 50 years ago, without things falling over, etc.? Is it budget? Time for testing and retesting (investors want returns)? Talent? Is NASA witholding its secret ingredients like a self-centered chef? (At least some national space agencies also have had problems, like JAXA, but I'm not sure how widespread that is.)

Edit: I would make it competitive, though. That's the point of private business - it can fail and disappear. Compete for the next contract.

We are definitely closer to the biplanes era of landing on the moon than we are to the Concorde era, as far as technological readiness goes. The pace of moon landers created has been much slower than the pace of airplanes built was in the early days.

Yup. The most fun fact about early aviation I heard that highlights how fast and loose everything was is that General Henry Harley Arnold in charge of the US Army Air Force during World War II learned to fly from the Wright brothers.

Not sure who you are quoting here, I never said "embarrassing". I'm sure that those "nerds" made adjustments based on the failures. That's all I was asking for.

They should ask the moon for a refund, or at least a "thank you".

I don’t make comments based on what I want to happen

An entire federal agency was deleted and thousands of non profits and other organizations were using the funding source as their only client and are also deleted now

Just because this one is publicly traded we should expect a different outcome?

I love prediction markets because now there is another outlet for perceiving politics than just debating. I take your money in a zero sum game if my worldview is more accurate, love that. I would almost say it rewards having a contrarian view of the world, but there are some psychology studies that show even ideologues like you will make accurate predictions if there is a payout of basically any amount. So I doubt it’s actually a contrarian view given that you have the same information.

> One similarly structured craft (thin and tall) reached the Moon a year ago, and also eventually toppled.

Presumably it's that shape to fit in the fairing of a Falcon 9?

No, that's not why.

I found dimensions and a picture of IM-1 here:

https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id...

The IM-1 lander was 1.57 meters wide and 4m tall, but based on the picture I think the width doesn't include the legs.

The Blue Ghost lander also launched on an F9; it's 2m high and 3.5m wide, and it landed without falling over. (dimensions from https://en.wikipedia.org/wiki/Blue_Ghost_Mission_1)

The F9 payload envelope dimensions can be found on page 79 of:

https://www.spacex.com/media/falcon-users-guide-2021-09.pdf

Dimensions shown appear to be <inches> [ <millimeters> ] - the bulk of the space is a cylinder with a radius of "180.020 [ 4572.5011 ]" which I read as just over 4.5 meters in diameter; the cylindrical part is just over 6.6 meters high (and then you get into the conical section at the nose).

The space inside the fairing is bigger than this but there is empty space between it and the payload to ensure they don't come into contact due to vibrations, etc., during launch.

So IM-1 could well have been wider and shorter and still fit on the F9.

Absolutely no substitute for research and the facts. Thanks for the research.

Correction: (too late to edit): cylinder with a diameter of "180.020 [ 4572.5011 ]"

You can fit a crab sideways in the Falcon 9.

The guys designing this never played kerbal space program or something. My first mun lander looked like theirs and of course it fell over after landing. If something doesn’t work in KSP, it probably deserves a looking at in the real world.

That should be an official NASA spec. Must not fall over on kerball.

Anyone playing KSP learns that. So the question then is, what did their tall and skinny design optimize for?

Minimal launch cross sectional area. Tall and skinny. ( Please check previous documentation )

I was completely off.

“This profound opportunity to make history isn’t solely built on technology – it’s established through the relentless dedication of our people, who have turned the Company’s words about a reliable cadence of lunar missions into action.”

Looks like the company is in alignment with NASA. I am actually impressed.

I would now look for a failure in one of the leg compressors.

Minimal launch cross-section is equally achievable for an oblong landing craft that is designed to fall on a predetermined side, with landing gear deployed to support it in the horizontal configuration.

Imagine a truck with a jet engine that lands on the rear end, then falls onto its wheels, because it's designed to operate when positioned horizontally.

https://www.intuitivemachines.com/post/intuitive-machines-im...

Look at the lander. Pray tell, if you want it shorter, where is everything supposed to go?

That doesn't look space constrained to me. The core looks like it would almost fit on it's side without modification, "just" move a few things around so it's flat and wide instead of tall and thin.

Here's exactly that:

https://x.com/SERobinsonJr/status/1879361461002371351

Nova-C (Intuitive Machine's platform) is 3x2x2 meters, and fits in a Falcon 9. Blue Ghost is 2x3x3 meters, and fits in the same fairing.

Here's a comparison (note that the Blue Ghost platform is currently the only one to succeed at it's intended mission, though IM1 did technically land safely but sideways):

https://i.ytimg.com/vi/PVz5912B1iQ/maxresdefault.jpg

It could be two landers, one stacked on top of the other for takeoff, but separate for landing

EDIT: or a horizontal lander, packed on it's side for takeoff.

I'm sure it's more complicated than that, but landing something this tall seems quite complicated too in the first place.

This is really thinking outside the box. Please read digital Apollo. It's that good.

go bigger this could be a pancake stack that separates into a swarm of puck like units according to some sequence

You’d be paying the extra mass cost of landing gears for each pancake - something has to absorb the impact of landing or they’ll just break apart. These landers already operate at the margin.

You do not need as many landing gears. No meat bags to protect, but you would need separate propulsion units, less the fuel for return trip. Landing gear is light weight. What was the landing gear ratio in other NASA unmanned probes? How did the asteroid interception land?

This is probe #2 from the company - NASA did not get there until Apollo 11 they are not the same... Computers are almost a billion times faster.

This is off the hook out side the box. If you landed functional units and the had some mechanism to connect them back up, you could reduce the force of landing... Oh wait.. this is exactly the plan for colonisation.

Seriously read digital apollo

This! Don’t base your designs on 1950’s sci-fi movies with big glistening rockets standing 50’ tall touching down on angled fins.

maybe make it like a hamster ball.

edit: just realized my own stupidity, a ball would be very hard to land..

That worked OK for some Mars rovers.

https://en.wikipedia.org/wiki/Mars_Exploration_Rover#Airbags

See also the section "uprighting", further down the page - they used a tetrahedral shell with a sensor so it knew which side was down and could lever itself upright.

A mars lander was like that but air bags

three actually

that ball would bounce for a long time and roll for a while until stopping, and unfolding into tetrahedral hemisegments, each in its desired orientation.

I mean, eventually everything is crab right?

Crabs cook well, but do not fly well,not drop in the vacuum of space well. But by no means dismiss this idea. It is interesting, I just do not know how right now. Their exoskelton legs. If the craft rotated like a cat,and landed like one with a dozen crab legs...where is Adam Savage when you need him?

Mandatory xkcd 2314.

not 'similarly structured' but the immediate sibling craft - the same design from the same company.

not "eventually toppled" but broke a leg and landed on its side right away.

Definitely the next mission will be the same craft - they have 2 more in the works.

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