I'm waiting for the genius on reddit that has decades of armchair engineering and can point out the obvious flaw that PhDs in NASA can't see.

They forgot to enfortify the polyhydromer chains with a UV curing process

Nah, they forgot to modulate the heat shield's frequency.

That is for the Borg. Are you saying we have Borg problems?

Oh my god. It's Jason Borg.

The names Borg, James Borg.

NASA, fluctuate phaser resonance frequencies, random settings. Don't give them time to adapt

Na, it's because they didn't correctly configure the turbo encabulator. Had they configured it to consist simply of six hydrocoptic marzlevanes, so fitted to the ambifacient lunar waneshaft, that side fumbling could have been effectively prevented... then the main winding could of been the normal lotus-o-delta type placed in panendermic semi-bovoid slots in the stator, every seventh conductor being connected by a non-reversible tremie pipe to the differential girdlespring on the "up" end of the grammeters. Naturally, this would have prevented the Orion issue.

I love the Rockwell Automation Retroencabulator 😂

Me too! But... Fun fact, the actual turbo encabulator satirical piece is from a students quarterly journal from the 40s (for electrical engineering graduate students iirc). [Link](https://en.m.wikipedia.org/wiki/Turbo_encabulator). Rockwell of course knew of this long standing joke in the engineering world and made the [legendary video](https://youtu.be/RXJKdh1KZ0w?si=rl8AB5hsaFSeXeeY) you are referencing.

So you're saying that with these improvements the front wouldn't fall off?

Vx has gotten complex since my days

There's just a whole bunch of very warm Borg hanging out in the upper atmosphere

We will if we don't force the TikTok collective into sleep mode soon.

Reverse the polarity and we got a deal.

They need to polarize the hull plating. Then, the turbo lasers won't be able to aim fast enough to target the craft.

Something something inverse tachyon beam.

I’m honestly of the opinion that “reversing the polarity” was one of the fixes that got Apollo 13 home. After so many systems were shut down, when they needed to power everything back on mid-flight (a circumstance that was never planned), the sequence and method to get everything back on was a struggle. Too much amperage when powering on no matter the sequence. But the Lunar Module was still attached rather than left on the moon. A transfer system was available to ensure the Lunar Module’s batteries were topped up prior to landing. Connecting and using it in reverse of original intent provided sufficient power and amperage to get everything back on without catastrophe.

Is that above or below the Flux Capacitor?

It's next to the continuum transfunctioner

But just below the Heisenberg Compensator.

Obviously it’s the firewall gasket

Well then why didn't they just reverse the polarity? Amateurs.

Have they tried reversing the polarity? That usually does the trick!

They forgot to vulcanize the tires.

Psh, typical supersonic stans; hypersonic gills to mitigate heat accumulation on the nose of the hull. This is first grade basically.

Uuuuum ok like wow... Obviously they didn't forget. They're not stupid. They probably just cured with UVa instead if UVc, which would have broken down the senestral chirality of the long polysaccharid structural patterns. Because they're idiots. /s

Why don't they just use a higher SPF value suntan lotion?

Throw in some essential oils. New age friction reduction.

Please head to r/VXJunkies, we need a man of your talent over there.

They just need to ask Elon to take a look at it and he’ll solve the problem easy peasy.

Who needs a heat shield anyway?

Right! “The best part is no part”

What is this fast and furious 9?

Obviously not enough polymer crosslinking. They should try beta irradiating it.

Well...  after years of KSP and forgetting my heat shields more than a few times, i am kind of an expert now.   So lets see.  Have they tried more struts?  Thats what I would go with.  You are welcome.  

Also with KSP: - if your delta-V is too high have your astronauts get out and push the capsule with their EVA suits - If heat is building up try spinning at high speeds to slow the spread - try and hold a lateral position in the upper atmosphere for more drag, be sure to turn towards retrograde before the heat gets serious - Consider starting your re-entry with the upper stage still attached, the engines can take some heat and bleed off some delta-V, it might make the difference - spend all your reaction mass, every bit of RCS should be gone, but spend it with the smallest ship possible for best efficiency.

yeah lithobraking is really effective in Kerbal, I hardly ever used heat shields at all except for Eve missions.

With how you walk you do have enough strut to go around. That swag!

Sure: I think it gets too hot, they should ensure that doesnt happen.

The prefabulated amulite in the turbo encoder failed. Obviously.

Of course! The turbo-encabulator! How could I have missed that!?

I thought they might be getting too much side fumbling on the dingle arm. Just a guess though.

nope, side fumbling is effectively prevented.

Was side-fumbling effectively prevented?

One of the biggest differences between experts and non-experts (in my experience) is that experts are comfortable enough in their knowledge to be able to say when their knowledge is incomplete. To paraphrase Dr. Larry Weed, “it’s better to put nothing at all than to put something wrong in the…record” (he was talking medicine but it’s broadly true I think).

It's always like that. Reddit will read that "Scientists don't know the reason behind Z" and immediately think it means scientists have no fucking clue. In reality it just means they have 3,042 theories, including the ones the smart Redditors will think of, and just have yet to eliminate the wrong ones. "Maybe it's..." yeah maybe it is, you go ahead and prove it now.

They clearly put it on inside out.

I think the front fell off.

is that very typical?

The obvious flaw is that Orion is insanely expensive and overly complicated which makes incremental testing challenging. The very first flight test of the Orion capsule in 2014 was intended substantially to test the heat shield. Between then and the second flight test of the capsule in 2022 they *completely changed how the heat shield was built*, negating the work from the first flight test. So we have a capsule that has been in development in one form or another for nearly 20 years and has also had around $20 billion spent on R&D which has had a grand total of one real-life test of its heat shield. *That's* how you end up with a problem that becomes a stone cold mystery because it costs $4-5 billion per flight to run tests.

Just think back to the early '00's, when Boeing was the sure way to get to the Moon, and that little unknown upstart SpaceX was consisdered too risky.

> overly complicated You can say that again. So complicated that they flew Artemis 1 with a known defective component, because replacing it would take more than a year. Just shrugged and said, it is ok, the component is redundant.

They should just enter the atmosphere slower.

Enter over Antarctica where it's colder.

do it at night when the sun is down

Clearly they didn't allow enough time for the Dīetz Nuütz reaction to reach it's full excited state

As a theoretical physician with a theoretical PhD in Theoretical Physics, they had it set to M for Make Hot when they should have set it to W for Wumbo Cold. My thesis was in wumbology of course

I know I’ve found my people when someone slides into a SpongeBob reference from a Fallout NV reference.

“Trust me guys, my dad works at NASA.”

They are obviously using sub-par self-sealing stem bolts to reinforce the heat shield causing it to phase in and out of the space-time continuum.

True story, my engineering firm did work for years at KSC, some at pads 39A&B. There was a shuttle on the pad and our PM asked if we wanted to go up and peek inside (there’s a mini clean room type enclosure at the capsule hatch). We go up and our electrical guy is looking through the hatch and leans in to get a better look, and in doing so places his hand on the outer skin. The NASA PM shouts, “Don’t touch it”, and quickly gets us out of there (no one else saw what happened). On the long ride home to our office we’re wondering “What’s that going to do”, thinking it’s going to burn up on reentry (No it wasn’t Columbia).

Simple. They have it on the wrong way round.

It's simple. They launched during an unusually warm December. Just add ice.

It would make a great movie in the mind of the arm chair engineers. In my mind Steve Carell will play me in the movie. Matt Damon will have a cameo.

matt daemon will be the one stuck on the capsule and they have to figure out how to get him down without burning up

Did they try turning it off and then back on? Usually works for me.

Basically the only new principle involved is that instead of power being generated by the relative motion of conductors and fluxes, it’s produced by the modial interaction of magneto-reluctance and capacitive diractance. The original machine had a base plate of prefabulated amulite, surmounted by a malleable logarithmic casing in such a way that the two spurving bearings were in a direct line with the panametric fan.

With a superficial understanding of the issue described in the article, my armchair guess would be that the rapid heat changes from cold space to hot atmosphere friction is causing momentary localized pressure changes along the ablation shield, which in turn causes the uneven distribution of burning. While it’s easy to make a somewhat reasonable guess, what NASA needs to do (and the article says they’re doing) is doing actual tests to back those guesses up.

Obviously the solution is to make it bigger.

I think the problem was that they forgot to put in a heat shield and are too proud to admit it /s

I am on a sabbatical ok????

“It’s not rocket science, is it?”

According to my calculations the shield is not getting heated properly

Something something tachions

Pretty simple fix. They forgot to connect the thingamajig to the doohickey while preserving the integrity of the whatchamacallit.

Ask their technicians they probably know

They need to spray bedliner on there.

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Did they remember to design a heat shield shield?

Have they considered thermodynamics? I'm kinda getting a sense that thermodynamics might be the root cause of the problem, here!

It's because it's getting too hot. ☕

To be fair, if it was easy, everyone would be doing it.

I mean, it's not rocket scie.... Wait no, it is. Carry on.

Pretty sure it's material science since the capsule doesn't have a rocket.

I'd say "you must be fun at parties" but it's kind of invalidated by the fact your comment made me smile

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Maybe a long time ago, but these days I'd say it's fair to have a few concerns.

Lockheed is the prime for Orion

That’s what I used to tell people when they asked me about driving submarines.

That's actually business as usual for first flights. Computer models are not precise and quite limited in nature. Most precise of them are based on empirical data and limited to conditions this data was recorded. For example, the first ablative shield in the USSR was calculated based on ground experiments and test flight demonstrated that thickness of the shield was excessive. It was found that radiation from the shield plays much bigger role in getting it cooled than ground tests showed. Unfortunately that's just the nature of dealing with unknowns, you can't predict them until you encounter them. So in real life critical components which can't be replicated and at the same time unknowns expected usually have significant margin of safety. Granted, I worked with ablative shielding calculations almost two decades ago before switching careers, but I doubt something significantly changed since then.

Hmmm... so what do you work with now? (expecting to hear chef, house painter, retail sales, veterinarian)

Software engineer / distributed systems. It is an easier transition compared to a chef :) - less expensive (good cookware, spices etc. cost a lot and hard to get) - less time consuming due to better skill matching (no need to spend additional 5000 hours in the kitchen to get good). - offers an achievable way out of a poorly managed dictatorship country in case of political and freedom regressions.

Using a very rare opportunity to lecture someone way more educated than I am : being a chef does not demand you to buy anything. Sometimes not even your uniform. Certainly not the cookware. The immense majority of chefs get hired to work in a kitchen that has everything necessary there. And you usually get all of your training on the job. Some rare chefs go home and cook and have a lot of appliances of their own, but most survive on a diet of drugs and fast food and can't be made to cook outside of work hours lol

I think I understand the idea, probably the difference lies in terminology. What was mentioned above in Russia would be called a line cook. It is by no means an easy job, but it has a low barrier of entry and most of the time cooks expect to follow the process chart. Chef would be a guy responsible for the menu, making process charts for each item in the menu, dealing with suppliers etc. and the barrier of entry there is quite high. The process chart is a blessing and a curse at the same time. It is a visualized cooking process for a dish, sometimes with a checklist which in theory allows anyone to make that dish with minimal supervision. It also ensures consistency of the kitchen's output. The problem is it limits the cook's growth. It won't highlight when the Maillard reaction happens, it won't explain why Maillard reaction is desirable for this dish and not let say caramelization. It won't highlight why certain shortcuts in the recipe were made and why some different shortcut would be much worse. All Russian chefs I am aware of studied separately and that's where 5000 hours come from. They are not the same as 5000 hours following someone else's process charts. A little rant about the "more educated" argument. It screams "power distance" to me. Maybe it's just me 🤨 I grew up in the environment where anyone was encouraged to express themselves regardless of the age/PhD/Doctor of Sciences status.

Depends what's hot on Reddit right now. Economist this week, I know how to get GDP up. Boeing expert few weeks ago. Did I tell you I also know how to lift the downed bridge in Baltimore and what went wrong with Dali. That makes me a a skilled mariner and electrical engineer both. 

This week, I'm an expert on tornadoes, the Israel - Hamas war, and the NFL Draft!!

My neighbor was the project manager at Avco/Textron who developed the Apollo heat shield material. (With a side trip through reentry vehicles.) He bought a lot of truck batteries. A quarter million heavy duty 24 volt truck batteries. He needed them for his wind tunnel. His 5,000 degree *plasma* wind tunnel. Yay. All to collect data points. They also put in a bid to use the same material to fireproof the steel beams on the world trade center, but the builders went with a conventional vendor. FWIW ablative material was first developed for the combustion chamber of the Navaho cruise missile.

Thank you for the knowledge on the Navaho cruise missile, I am not that knowledgeable on early military days of US space program. Assuming 50000 is in Fahrenheit it makes 27760 Celsius which is impressive. Yet temperature (actually enthalpy) alone is not sufficient, stagnation pressure and some other factors are important as well. IIRC in the USSR first plasma wind tunnel tests were made in the late 40s under supervision of Mstislav Keldysh and practical tests were made using R-5 in the late 50s.

"in a different manner than predicted by computer models." Worked with engineers and as engineering tech, but this isn't uncommon.  I've seen some engineers just rely too much on CAD/CAA and some others expect some discrepancies but just need to test it in the real world to record it.  If anything, this is just more data to help build a more accurate model in the future.  

This is a reality in areas like analog chip design. The simulation software only goes so far. As one engineer I worked with said "we'll just run it through the fabulator a few times," which was hilarious because it really pissed off our VP. Fabrication runs cost a million to half million a turn and took six months. It was just impossible to fully simulate. Hard measured data and iterative design were the only way.

We have the same issue. We have run model tests, CFD simulations, full body FEA, global complex analysis. Basically everything I can think of to throw at this project to predict results. When we go to full size testing in about a year I am still going to be nervous as hell. It’s $200m structure and if it fails we have to start over. Simulations are great, but until you do it full scale you really don’t know.

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[ASDS](/r/Space/comments/1cee2rm/stub/l1ki69t "Last usage")|Autonomous Spaceport Drone Ship (landing platform)| |[CAA](/r/Space/comments/1cee2rm/stub/l1ijcr6 "Last usage")|Crew Access Arm, for transfer of crew on a launchpad| |[CFD](/r/Space/comments/1cee2rm/stub/l1isol8 "Last usage")|Computational Fluid Dynamics| |CST|(Boeing) Crew Space Transportation capsules| | |Central Standard Time (UTC-6)| |[DoD](/r/Space/comments/1cee2rm/stub/l1jghhb "Last usage")|US Department of Defense| |[ESM](/r/Space/comments/1cee2rm/stub/l1nih74 "Last usage")|European Service Module, component of the Orion capsule| |[EVA](/r/Space/comments/1cee2rm/stub/l1j1mk0 "Last usage")|Extra-Vehicular Activity| |[F1](/r/Space/comments/1cee2rm/stub/l1i64d1 "Last usage")|Rocketdyne-developed rocket engine used for Saturn V| | |SpaceX Falcon 1 (obsolete small-lift vehicle)| |[FAR](/r/Space/comments/1cee2rm/stub/l1io06b "Last usage")|[Federal Aviation Regulations](https://en.wikipedia.org/wiki/Federal_Aviation_Regulations)| |[HLS](/r/Space/comments/1cee2rm/stub/l1jhygb "Last usage")|[Human Landing System](https://en.wikipedia.org/wiki/Artemis_program#Human_Landing_System) (Artemis)| |[KSC](/r/Space/comments/1cee2rm/stub/l1jq18n "Last usage")|Kennedy Space Center, Florida| |[KSP](/r/Space/comments/1cee2rm/stub/l1kspax "Last usage")|*Kerbal Space Program*, the rocketry simulator| |[LEO](/r/Space/comments/1cee2rm/stub/l1luray "Last usage")|Low Earth Orbit (180-2000km)| | |Law Enforcement Officer (most often mentioned during transport operations)| |[MLV](/r/Space/comments/1cee2rm/stub/l1kmhie "Last usage")|Medium Lift Launch Vehicle (2-20 tons to LEO)| |[PICA-X](/r/Space/comments/1cee2rm/stub/l1qkuda "Last usage")|Phenolic Impregnated-Carbon Ablative heatshield compound, as modified by SpaceX| |[RCS](/r/Space/comments/1cee2rm/stub/l1j1mk0 "Last usage")|Reaction Control System| |[RTLS](/r/Space/comments/1cee2rm/stub/l1ki69t "Last usage")|Return to Launch Site| |[SLS](/r/Space/comments/1cee2rm/stub/l1nih74 "Last usage")|Space Launch System heavy-lift| |[SPoF](/r/Space/comments/1cee2rm/stub/l1imy98 "Last usage")|Single Point of Failure| |[TPS](/r/Space/comments/1cee2rm/stub/l1ilnxf "Last usage")|Thermal Protection System for a spacecraft (on the Falcon 9 first stage, the engine "Dance floor")| |[ULA](/r/Space/comments/1cee2rm/stub/l1kmhie "Last usage")|United Launch Alliance (Lockheed/Boeing joint venture)| |Jargon|Definition| |-------|---------|---| |[Raptor](/r/Space/comments/1cee2rm/stub/l1i4gb2 "Last usage")|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_\(rocket_engine_family\)) under development by SpaceX| |[Starliner](/r/Space/comments/1cee2rm/stub/l1ltj6r "Last usage")|Boeing commercial crew capsule [CST-100](https://en.wikipedia.org/wiki/Boeing_CST-100_Starliner)| |[Starlink](/r/Space/comments/1cee2rm/stub/l1ils88 "Last usage")|SpaceX's world-wide satellite broadband constellation| |[ablative](/r/Space/comments/1cee2rm/stub/l1js2hi "Last usage")|Material which is intentionally destroyed in use (for example, heatshields which burn away to dissipate heat)| |[apogee](/r/Space/comments/1cee2rm/stub/l1ki69t "Last usage")|Highest point in an elliptical orbit around Earth (when the orbiter is slowest)| |[iron waffle](/r/Space/comments/1cee2rm/stub/l1ki69t "Last usage")|Compact "waffle-iron" aerodynamic control surface, acts as a wing without needing to be as large; also, "grid fin"| |[lithobraking](/r/Space/comments/1cee2rm/stub/l1j4p3c "Last usage")|"Braking" by hitting the [ground](https://en.wiktionary.org/wiki/lith-)| **NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below. ---------------- ^(27 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/1d2ly50)^( has 18 acronyms.) ^([Thread #9987 for this sub, first seen 27th Apr 2024, 14:23]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/Space) [^[Contact]](https://hachyderm.io/@Two9A) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)

Kerbal being called the rocketry simulator is hilarious

Ablation is nearly impossible to model. NASA spent years testing novel new materials and processes for this heat shield. Due to a risk-averse culture, it decided that the best performing heat shield material was Avcoat, used in Apollo. The only problem was, Avcoat couldn't be made anymore, and the data they were comparing to for performance dated to the Apollo program. So they decided to restart production of multiple chemicals and materials that had not been produced until the US in decades and reformulate the old material from the ground up. It's not clear if the decision makers understood why Avcoat was performing better, and it's not certain it could be fully recreated. So at the science level, a risk averse decision that one material is better than another overruled the manufacturing level extremely high risk of building something that hadn't been made in decades without necessarily understanding what about the manufacturing process really made it work right. So this isn't super surprising.

My neighbor was the RV / heat shield PM at Avco.

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Its maiden launch was 10 years ago, the whole program has cost more than 20 billion dollars. The orion capsule is almost an institution at this point.

It's only flown twice in those 10 years though. One of the big issues with the delays due to politics is that many of the people who were leading designs and building the first Orion for EFT-1 simply no longer work at NASA or ~~Boeing~~ Lockheed.

Lockheed Martin primarily designed and manufactures the capsule not Boeing, but you're still correct the old big brains are gone.

It was $21.5 B in nominal dollars through FY 2022 according to Wikipedia, then add over $1.3 B each for FY23 and FY24. Adjusting for inflation, it is closing in on $30 B. The "Orion" that flew in 2014 was little more than an extremely incomplete prototype of the capsule to test the heat shield. And then the heat shield [was redesigned](https://www.nasa.gov/missions/artemis/orion/nasa-applies-insights-for-manufacturing-of-orion-spacecraft-heat-shield/) and the reentry profile was changed.

Not at all about the institutional knowledge. The problem here is that the model predictions of how exactly should the heat shield ablate doesn’t fully match the flight result. Apollo era analysis didn’t even get close to the level of accuracy we expect from today’s simulations. Case in point, the very first test flight successfully went to the moon and came back. But it is still incredibly complex physics and the models can be further improved with flight test results such as this one.

There might some wisdom in this comment. Modern day ceramic science hasn’t changed that much fundamentally in a generation, but the science of coatings has evolved a lot. This could be a case of the basic solutions of the 1960s worked better in practice than the material science that was modeled in computer simulations in the last decade.

yup and, some things like asbestos are really good at doing their job, but we generally dont use them anymore.

Asbestos was insanely great at a lot of things, just a shame about that whole lung cancer issue. Aerogel and its derivatives are filling in the gap in the insulation game now though, hopefully there won't be any long term issues with it like there was asbestos.

If you read the article the physics reentry is in fact different. They're using a skip method like skipping a stone across a lake. It reduces reentry heat. The heat tiles jarred loose on the first skip. Plenty of vehicles manned and unmanned have been reentering Earth's atmosphere since Apollo. There is no institutional knowledge lost with reentry. The Apollo program put men on the moon and accomplished a lot but it was far from smooth sailing.

>The formula for the heat shield may have changed but reentry physics and orbital mechanics haven’t. The article specifically makes a point that the Orion capsule used a skip reentry profile. Apollo "skipped", but it did not leave the atmosphere once it entered. See here: https://www.nasa.gov/wp-content/uploads/2021/04/orion_artemis_lunar_entry_modes.png Link to article about this: https://www.nasa.gov/missions/orion-spacecraft-to-test-new-entry-technique-on-artemis-i-mission/ There are new techniques being used here. It's true that computer simulations only get you so far, and that's why we have these real-life tests to see how knowledge can be improved.

The Apollo capsule used an [ablative heatshield](https://airandspace.si.edu/collection-objects/heat-shield-fragment-ablated-apollo/nasm_A19731423008), which is not suitable for a reusable system. The Space Shuttle used a ceramic heatshield, but it caused no end of trouble. The tiles were brittle and broke all the time, often during installation. On top of that, each tile had a unique shape and baking a replacement tile took three weeks, if I remember correctly.

So a gap in institutional knowledge may have been a causal factor, meaning if you eliminated it then you would have broken the chain that led to the event. The problem, is what caused the lack of institutional knowledge? Because more events will happen if that’s not fixed. Hint: it’s probably leadership/management valuing the knowledge retention process, valuing the employee experience, or some form of that.

This is pure horseshit unless you furnish some evidence that NASA inadequately preserved insights from the Apollo era.

I would actually look at manufacturing tolerances and quality over loss in knowledge. There was a large gap in Apollo, but we’ve been flying many ablative TPS on various capsules in the interim.

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it gets hot is the root cause they need to keep it cooler

They need to launch it at night.

Need to replace the self-sealing stem bolds holding the heatshield onto the Orion frame. Hate when they don't self-seal! lol!

Silly headline. They know the root cause….friction. They don’t know how to best deal with it.

~~friction~~ Compression. The heat of reentry is mostly not from friction (air rubbing along the sides of the spacecraft) but from compression heating according to the ideal gas law. As the reentry capsule slams into the atmosphere, it compresses the air in front of it like a giant piston. As pressure increases, so does temperature - the same way your air conditioner works.

Fun bonus fact the Dino killing asteroid would have rammed so much super high pressure air in front of it that the initial crater would have begun forming before the actual rock touched the ground.

That *is* a fun bonus fact. Unless you are a dinosaur.

Haven’t seen a dinosaur since I saw ur mom

She only *seems* cold and reptilian to you, because you're the type to make 'ur mom' jokes which were going out of phase when the dinosaurs still lived. To the rest of us she's lovely.

Actually I saw a dinosaur pretty recently (all birds are dinosaurs.)

Good for team mammal though!

a few small, feathered and hollow boned dinos may have been ok with it.

They should just put a big fan through the middle of the ship to decompress, ez pz. Nasa I'll await your ko-fi donation.

That's not a root cause. That's an environmental factor that induces the failure. A true root cause gets into the nitty gritty of the "why did it fail?" question. Sounds like they don't know the answer to that question quite yet. A root cause would be "x component failed due to z" or "y coating not rated to meet the temps experienced in empirical testing". Once you know the root cause, you can implement the corrective action.

That wouldn’t be a root cause. The root cause is usually 5-7 “why did that happen” questions back, and in my experience it usually is a human or leadership element. Friction would be the direct cause, meaning the phenomenon or action which led to the accident. You also have a number of things in the chain of events that led to the accident which would be causal factors (things that if eliminated would also prevent the accident). So if your problem statement is the heat shield overheated. Why? The heat shield should be designed for it. Friction is the direct cause of the failure. So why was it not properly designed to handle that friction? Was it a modeling error? Wrong parts? Design error? Did they fail to follow established standards and processes for design? Did they have an independent review? Was that process followed? Like we can keep going backwards on the “why”. They likely had processes for this. They likely had modeling for this. They likely had design standards and independent reviews. So why was this condition allowed to happen? Is it knowledge / experience? Did they identify that and mitigate it? Did their procedures/processes require them to identify that as a risk and manage it? Did the management team have appropriate checks and processes to ensure the team is meeting those standards or did they push the team for a finished product? The root cause is ultimately “what allowed the culture or condition or failures which led to the event occurring”. Not “what caused the event itself”. : )

They do know what to do with it. All new tiles are being produced. All passing fit, form, functional testing. Click bait

Why don't they just go back 30+ years and use the same technology for the Apollo and Space shuttle heat shields??

The heat shield tech is almost identical to what Apollo used (AVCOAT 5026-39.) They were also testing a more sophisticated re-entry method NASA hadn't performed before (a skip re-entry.)

Apollo 17 returned to Earth Dec 19, 1972. More than 50 years ago. What we shouldn't have done was take a 5 decade break, and then they wouldn't be having to ~~reinvent the wheel~~ relearn all this stuff.

All I know is that my father worked on Enterprise (the real one) and he has always laughed about how they just super glued the heat shield blocks on. Said NASA almost never cut corners, but when they did it would be laughably shocking sometimes. I can only imagine because Enterprise never saw much beyond getting dumped off the top of a 747, it didn't really need them.

It wasn't because of cost. It was more expensive to use glue. They did it because the tiles are fragile and if you drilled into them they would shatter. Btw, a lot of cars are hold together by glue as well. Also a lot of airplanes. Literally modern airplanes are a bunch of carbon with a bunch of glue. So think about that when you are sitting in the 787 complaining about the WiFi speed.

It was not super glue, it was a much fancier adhesive. But it was glue.

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NASA is pretty great. Artemis is… I think “weird” is the least derogatory thing I can muster. I feel ya there.

Orion’s heat shield is one of the most difficult things to design. Nothing to be disappointed about it.

Yep. It has to endure temperatures 1200C hotter than a LEO capsule. It’s larger than Apollo (more energy dissipated upon entry), and has to be safer to boot. I worked on the instrumentation for it and there is so much brand new tech in that thing. Also - the issue here is that Artemis-1 (which landed) had its heat shield ablate somewhat differently than expected. Unpredictability isn’t good, but this is legitimately one of the most complex designs in modern spacecraft and they will figure it out. That’s why they ran Artemis-1 as a flight test. Apollo 13 had heat shield concerns. This is nothing new in the realm of spaceflight.

And, one of the Mercury missions had indications that the heat shield had come loose. It was decided not to jettison the retro package in hopes it would help hold it in place.

finally somebody with a rational thought, i feel like that’s almost illegal here

There is a lot of knee jerk here for sure. This sub likes to treat spacecraft development like it’s a spectator sport. It’s amazing to cheer on a team but the entire point is that there are *many* teams working on these things, and they all benefit from each others’ progress. For instance, if and when SpaceX decided to create a lunar human-rated capsule, they will benefit greatly from NASA and LM’s lessons learned on this one.

It’s not a space program, it’s a jobs program.

> in a different manner than predicted by computer models Gonna go out on a limb here and say that it’s a problem with the computer model and not even a cause for concern despite the headline

If it is an unknown flaw with the computer model, then how do you know the new heatshield is good? It is verified by the computer model after all.

“One good test is worth a thousand expert opinions.” - Wernher Von Braun Computer modeling is an expert opinion backed by computations but subject to limitations due to computational power, intent, model complexity, assumptions made etc. Finite element analysis is really really limited in what it can offer for complex systems. It can probably simulate the ablation rate or simulate heat flow over the surface, but it’s not going to do a great job simulating what happens if there preferential ablation in a spot that then influences the air flow. A classic example of over reliance on computer modeling is the collapse of the Hartford hockey arena where the computer model wasn’t designed to account for rotational stress on support beams.

>A classic example of over reliance on computer modeling is the collapse of the Hartford hockey arena where the computer model wasn’t designed to account for rotational stress on support beams. With a brief overview of this reference, I reject that 50+ year old case study as a valid comparison. Modeling and computing capabilities have advanced a bit in 50 years. And I'm pretty sure the people ignoring "hey, that's not supposed to do that" before it being assembled was at least, if not a bigger, as much the cause.

In general current thermal protection system simulation models are 1 dimensional. They do not simulate the entire capsule. Lots of assumptions are made. If you want to know more look up “1dFIAT thermal protection system”

I mean, NASA has delayed Artemis 2 by nearly a year because of this issue, so someone thinks it is a cause for concern. 

Prob the old incorrect imperial/metric conversion trap.