Anonymous sources: Starship will need a major rebuild after two consecutive failures
Starship just before loss of signal on March 6, 2025
According to information at this tweet from anonymous sources, parts of Starship will likely require a major redesign due to the spacecraft’s break-up shortly after stage separation on its last two test flights.
These are the key take-aways, most of which focus on the redesign of the first version of Starship (V1) to create the V2 that flew unsuccessfully on those flights:
- Hot separation also aggravates the situation in the compartment.
- Not related to the flames from the Super Heavy during the booster turn.
- This is a fundamental miscalculation in the design of the Starship V2 and the engine section.
- The fuel lines, wiring for the engines and the power unit will be urgently redone.
- The fate of S35 and S36 is still unclear. Either revision or scrap.
- For the next ships, some processes may be paused in production until a decision on the design is made.
- The team was rushed with fixes for S34, hence the nervous start. There was no need to rush.
- The fixes will take much longer than 4-6 weeks.
- Comprehensive ground testing with long-term fire tests is needed. [emphasis mine]
It must be emphasized that this information comes from leaks from anonymous sources, and could be significantly incorrect. It does however fit the circumstances, and suggests that the next test flight will not occur in April but will be delayed for an unknown period beyond.
I think the tweet however is much too pessimistic. If the problems are all within the fuel lines, engine wiring, and the power unit, they are well localized. Moreover, the design of these components on version 1 of Starship apparently worked reasonably well, which gives them a good basis for that redesign. Nonetheless, if these facts are correct, my guess is the next test flight won’t occur before June.
The one saving grace is that FAA red tape is clearly no longer an additional obstacle. It is very clear now that with the change from Biden to Trump it is letting SpaceX lead all investigations, and immediately accepting its conclusions and fixes, rather than sitting on those conclusions as it retyped them for weeks or months in its own report.
Hat tip to reader Richard M.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Starship just before loss of signal on March 6, 2025
According to information at this tweet from anonymous sources, parts of Starship will likely require a major redesign due to the spacecraft’s break-up shortly after stage separation on its last two test flights.
These are the key take-aways, most of which focus on the redesign of the first version of Starship (V1) to create the V2 that flew unsuccessfully on those flights:
- Hot separation also aggravates the situation in the compartment.
- Not related to the flames from the Super Heavy during the booster turn.
- This is a fundamental miscalculation in the design of the Starship V2 and the engine section.
- The fuel lines, wiring for the engines and the power unit will be urgently redone.
- The fate of S35 and S36 is still unclear. Either revision or scrap.
- For the next ships, some processes may be paused in production until a decision on the design is made.
- The team was rushed with fixes for S34, hence the nervous start. There was no need to rush.
- The fixes will take much longer than 4-6 weeks.
- Comprehensive ground testing with long-term fire tests is needed. [emphasis mine]
It must be emphasized that this information comes from leaks from anonymous sources, and could be significantly incorrect. It does however fit the circumstances, and suggests that the next test flight will not occur in April but will be delayed for an unknown period beyond.
I think the tweet however is much too pessimistic. If the problems are all within the fuel lines, engine wiring, and the power unit, they are well localized. Moreover, the design of these components on version 1 of Starship apparently worked reasonably well, which gives them a good basis for that redesign. Nonetheless, if these facts are correct, my guess is the next test flight won’t occur before June.
The one saving grace is that FAA red tape is clearly no longer an additional obstacle. It is very clear now that with the change from Biden to Trump it is letting SpaceX lead all investigations, and immediately accepting its conclusions and fixes, rather than sitting on those conclusions as it retyped them for weeks or months in its own report.
Hat tip to reader Richard M.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
“- The team was rushed with fixes for S34, hence the nervous start.”
What “nervous start” is being referenced?
Oh wow, I wasn’t expecting this!
I assume that anything I read about SpaceX these days is negatively amped-up by the media we have, whose job seems to be to distress the Americanpublic, and give hope to our enemies!
Eric Berger has a new story up today at Ars Technica that touches on this rumor, but aims for a broader analysis:
https://arstechnica.com/space/2025/03/after-years-of-acceleration-has-spacex-finally-reached-its-speed-limit/
Berger makes clear that he thinks that if anything might be to blame, it’s the SpaceX org culture (as in, “too much of a good thing”) than anything Elon Musk is doing, even as it’s pretty clear that Eric doesn’t dig what Elon is up to in certain political spheres. And he also makes clear up front that at the same time these struggles are happening, SpaceX’s Falcon 9 operations have reached an “unprecedented” cadence, on which most of the Western world now relies for its space needs — a staggering achievement.
I am kind of wondering, though, how much time Elon has spent down at Starbase over the last week.
Not sure Elon’s physical presence at Starbase is required to address roadblocks. I know he likes to be the blockage-clearer, but with the comms and processes he no doubt has, I am sure he need not be on site to do so.
Remember that SpaceX has the best people in the industry, and I’m sure they know when to hold for a superior’s input, or go ahead on their best judgement.
And I’m also sure people like COO Gwynne Shotwell and VP Vehicle Engineering Mark Juncosa know how to make sure that culture keeps working smoothly.
It is more likely in my opinion that the problem lies in too few top-notch engineers being available and lack of bandwidth to integrate them into a ramping-up development and production process.
Hello from France
Nice article from Eric Berger. Well i would not be surprised that the hard work done by the people working at SpaceX , hasn’t been without injuries.
I read an article saying that Reuters has investigating working conditions at Space X, and since 2014, there have been 600 accidents, and 1 death , previously unreported.
https://next.ink/700/des-centaines-daccidents-travail-a-spacex-depuis-2014/.
The link is in french, but i think you can translate it in english.
Like it has been said, doing 150 launched a year, with the pressure for some important missions,like for aviation, you have to make your job correctly, if you do a mistake, you can’t go back once the rocket is launched, it’s a Go or No Go.
I also know that the Starship are prototypes, they are testing several combinaisons of tiles, equipments, etc…
That could lead to a fail..
Of course, like Mr Robert Zimmermann uses to write, i will say ” Hat tip to Space X people”, because they do alot of hard work, that probably drives some of them to burnout ( I’m an aircraft maintenance mechanic, and i know the pressure to finish a maintenance check in time for delivery to the customer), but for rockets production, i think there are heavier risks, like manipulating oversize and heavy weight equipments, as producing or stocking liquid hydrogen and kerozen, that requires specific qualified technicians and safety rules.
Thank you for reading me.
Keep going writing space related articles, i love that.
Well, when I want to know what is really going on in the American aerospace industry, I always rely on Reuters. /S
Ps. Knew a lady who fancied herself a top-notch PR type who always pronounced Reuters like “Rooters”.
To avoid embarrassing her, I finally made up the story that a German friend of mine had told me it is actually “Royters” – it is a German family name. She laughed at me.
The next day she wasn’t laughing, or speaking to me any more! Oh, well.
Hello Herve,
Workplace safety is important, and no company, however successful, should be above the law. But I think there’s a lot of context missing from the Reuters story that needs to be unpacked, because some of it is frankly disingenuous.
There was an unusually good treatment in this regard over at the SpaceXLounge subreddit last year:
https://www.reddit.com/r/SpaceXLounge/comments/17zdeiq/how_dangerous_is_it_really_to_work_at_spacex/
Not sure Elon’s physical presence at Starbase is required to address roadblocks.
I might not have made clear what I was getting at.
It’s not so much that I am expecting him to clear roadblocks (something he has admittedly done at SpaceX during past crises), but that Starship is by far the most important development to SpaceX’s future, and it appears to have a significant hitch in its design. I’d like to think that the owner/CEO/CTO would want to at least be fully informed of what’s happening, and in the past, it *is* the sort of thing that would have had Elon camped out and sleeping on the floor until he at least fully understood what was happening.
And maybe he has been. I don’t track his movements, however, so I have no idea where he’s been the last several days.
It doesn’t surprise me that the hot ring for “Hot Separation” is number one on the list, the failures began when they added it to starship fixing one problem, but causing another. It’s apparent that heat/ vibration/ compression of a semi contained explosion is too much for the engines to take.
Hot separation was thought to be necessary to prevent fuel sloshing, a sledgehammer affect at engine cut off, followed by “ignition” driving the fuel down hard.
There are three or more corrections that can prevent this. They’ve tried the hot ring, now they need to try something else.
Baffles in the tanks will prevent sloshing as they do on tanker cars on freeways. A ratcheting baffle plate in the tanks will keep the fuel incapsuled to prevent movement with a release mechanism for refueling.
And/or oversized positioning jets above tanks, (below cargo hold) that provide thrust during separation, before main engines engage, eliminating the need for a hot ring.
(I believe in the design concepts, landing thrusters for moon and mars are located on the upper portion of the starship to prevent dust and rock blow back that would damage the craft and should be implemented in the new design “now” to prevent future failures)
Remember the crater created during the first launch? It destroyed the launch pad, throwing concrete everywhere, knocking out a few of the engines. Could you imagine what starship would do to the surface of the moon or Mars? No wonder the blowback is knocking out the motors…
They know what to do, the solution will be implemented.
“Could you imagine what starship would do to the surface of the moon or Mars?”
We don’t know much about what SpaceX is designing for the Mars configuration of Starship. But the lunar version (HLS) is supposed to have small thrusters mounted in a ring high up on the fuselage, both for final landing and takeoff — precisely to address the concern about dangerous regolith plumes.
Fair odds that they probably do something similar on Mars.
I am not prepared to bet that the fix will take a long time or a major redesign. Ship 35 is being ground tested for normal progression to flight.
I do like the idea of ullage thrusters for the booster to eliminate the hot staging idea. Will the thrusters mass more than the hot staging ring?
For years–the narrative is that Old Space is full of sleep o’nights and NewSpace more unconventional.
Yet Elon himself disproved this by going for an in-line design—where the parallel staging of ALS/NLS would have been free of the issues now plaguing.
I have in the past suggested that a smaller ship should have been used to get the wrinkles out of the methalox systems. I have also suggested (along with many other) that an expendable second stage would have been able to enter service much faster and cheaper with lower development risk. That being said, I don’t need to pile on.
Go back to Ship Block 1 piping arrangements with Block 2 Leeward swept fins.
Implement a “Go ahead and stop thrusting ” philosophy – Keep the jettisonable hot staging ring but only briefly pulse low throttled second stage engines to get separation, then jettison the hot staging ring and land the booster.
Use this variant to prove out payload deployment and heatshield technology.
Maybe use the same variant to conduct an orbital demonstration.
I know handwaving can get easy in situations like this, but give SpaceX some credit. They understand the problem, but the fixes aren’t easy. Lots of folks calling for ground testing, but that only goes so far. You have to fly, and fly they will.
Keep in mind both failures occurred at high-G loading in a vacuum. Tough to replicate on the ground. And hot staging works, and also helps with improved payload to orbit.
Others are “concerned” about the blowups, and yet, other than the minor inconvenience to air travel, no real impacts have been felt. No one is hurt, and the debris is at the bottom of the ocean.
Sit back and appreciate the fruits of their hard work. Big rockets are tough, but once you get a handle on them, they are simply amazing. After all, 3-for-3 on booster catch attempts already. Who’d have put money on THAT bet?
“Starship will need a major rebuild after two consecutive failures”
Almost like it’s a test vehicle
https://t.ly/YTEwm
Two comments: First, from my academic days oh so long ago I remember the challenges of Designing for Vibration (ME352 if memory serves) which are decidedly non-trivial.. So the fact that a new plumbing architecture (among I’m sure many other changes) may have triggered a catastrophic harmonic of some kind isn’t really too surprising..
Secondly system harmonics are extremely sensitive to the mass and configuration of the components and overall assembly as well as the frequency and characteristics of the forcing vibration. As Raptor V3 is considerably lighter and simpler than V2, requires considerably less shipside mass as well, and has reconfigured the component parts extensively, I would not be surprised if SpaceX continues apace with minimal changes from the current Starship V2 design and first attempts a test using Raptor V3s instead.
This is the ultimate goal anyway, so I expect the shipside design of Starship V2 is probably optimized for Raptor 3 with just a minimum of legacy compatibility added for Raptor V2 support. And even though Raptor 3s aren’t in high volume production yet we know that is now ramping and the ship only needs 6 per flight.
So switching ASAP may fix this harmonic issue all by itself and give them an extra 6 tom’s or so of mass to orbit margin.. And it just occurred to me that the mass delta will change the re-entry dynamics a fair bit too, so all the more reason to get on with it sooner rather than later.
For what it’s worth.
No need for pessimism. Lots of things have been proven. Booster works well. I’m sure the failure to light during boost back will be solved but in the meanwhile redundancy has been shown. Maybe on flight 7 the engine worked for final braking burn because the whole bottom of the booster was toasty warm.
Stage Zero works well with ongoing improvements.
Booster catch is better than 3 for 3. Would have been 4 for 4 if the antenna on the tower hadn’t been damaged and I think each time since flight 2 it has been placed where it ought to be on landing.
As for the ship, it has got to planned trajectory in V1, Raptor relight has worked on orbit. Re-entry is survivable and flip and soft landing seems pretty reliable. Astounding progress when you think about it.
Raptor seems amazing for a full flow staged combustion engine which configuration has never flown before, let alone with methalox.
No point in a smaller ship to iron out methalox as that doesn’t seem to be the problem and the smaller ship was V1 which worked fine.
Parallel staging has its own issues like ice impacts on heat shield of upper stage.
Elon isn’t interested in expendables.
It seems as though every time SpaceX stubs its toe a coterie of ill-wishers emerges from beneath their residential rocks and tries to make it out to be cancer or an aneurysm or some such catastrophe. Being perennially wrong never seems to faze them. Having predicted the last 137 of zero collapses for SpaceX, these types will unhesitatingly predict number 138 given the least provocation.
“Starship will need a major rebuild after two consecutive failures”
This is a situation where we will see what the caliber of leadership is at SpaceX.
I am NOT discounting any of the achievements of SpaceX to date. They have been spectacular AND unprecedented.
However, SpaceX now has its “headline” product having two spectacular failures in full view of the public (in the press and the sky). This brings pressure.
This is the time for true leadership. Leadership that values truth – true data and engineering opinions based on the data and engineering principles. Nothing is sacred – only the truth.
This is the time for leaders to insulate the design team from the pressure and charge them: “Get this correct – not necessarily fast – but definitely correct.”
This is where leadership asks: “What do we need to have to get this correct? ”
This does not mean they get a vacation. (I don’t think SpaceX knows what that is.) Time is still important – but not of the essence. A path to a solid design is the key.
Leadership will emphasize correct, not fast.
I expect that the next launch will be sooner than most expect, for the simple reason that vibration characteristics are different in static fire (spacecraft physically locked down) than in flight (spacecraft can vibrate freely). I hope that for flight 8, they planted accelerometers all over then engine compartment and “attic” to capture data on vibration and resonance. They need data to know what to fix, and they need to fly to get that data.
To MDN,
I want to pick your brain about the following article:
“New theory on dense gases and liquids could aid carbon capture.”
Despite it being a green article–there may be some insights in terms of propellant handling.
“For the past 50 years, experts in the field have claimed that developing a collision theory for liquids is impossible.”
That seems no longer the case.
Another seemingly unrelated article:
“Novel technique manipulates water waves to precisely control floating objects.”
We know harmonics impinge upon rocket bodies–might that be reversed with a fluidics based noise cancelling tech?
Old automatic transmissions look like fluidics microchips on the inside–might inert Tesla valve deals dampen some of this out?
Lastly… would it have been better if the Raptor locations were laid out in Sunflower type spirals?
I have heard some say you want to avoid vortices–I have read about vortex combustion.
Not sure what to think.
From the linked tweet (thank you, Richard M):
– Problems with the rupture of methane lines in the oxygen tank only appear as the tank empties.
– When filled, liquid oxygen dampens the oscillations of the distributed lines, when the tank is empty, they increase.
When it comes to vibration, everything is a spring.
That was one of my early lessons when I started working in aerospace. During sine sweep vibration testing, the guy running the shaker table sometimes would bring out a strobe light that was shifted by a small amount from the instantaneous frequency, and as the shake table went from low frequency vibrations to high frequency, the strobe light showed how the test item was deforming during the vibration. I am still impressed at how much a circuit board can flex without breaking.
I have been wondering whether Starship’s failure was related to the mass of the propellant tanks. During vibration, everything is a spring — everything solid, anyway. The natural frequency depends upon the mass(es) attached to the “spring.” As the mass changes, as the propellants are drained to the engines, the natural frequency changes. Both failures happened around the same propellant level in the tanks. This may not be coincidence.
Since the system must pass through this same mass at some time during the burn, then a possible solution is to change the spring constant of whatever is vibrating so much. Can they do this with the materials available? I don’t know.
The way it is phrased in the quote (above) from the tweet gives the general idea, but that is not the actual mechanism of vibration. The propellant is most of the mass in the system, where the mass and the spring value determine the natural frequency. The propellant may contribute some dampening, which would reduce the amplitude at the natural frequency, but it is the mass and the spring value that determine the natural frequency of a system. As the propellant tanks drain, their natural frequencies change. The propellant lines, however, remain filled, so their natural frequencies remain fairly constant.
Natural frequency means that a small vibration that happens at that frequency is enhanced to a larger amplitude for the parts that have that natural frequency. Not to be confused with the dynamic pressure “Q” at launch, the amplitude of the natural frequency vibration is related to a vibration “Q” factor, which relates the damping of the system (including the natural damping of whatever is behaving as the spring) and the increase of the vibration amplitude. High Q means low damping and higher final amplitude than that of the vibration source, and low Q means higher damping and low final amplitude. The parts of the system are stretched and stressed, possibly to the breaking point. This is most likely to happen to whatever is acting as the spring or whatever is holding the spring in place or holding the mass to the spring.
From the quote (above), it seems to me that the methane line has a mass (the methane within the line) and spring value (the propellant line itself) combined as a system with a natural frequency in the range of a natural frequency in the Starship rocket. It sounds like the oxygen in its tank (the tank that the methane line goes through) acts like the oil in a dashpot, and the Q is low until the oxygen level becomes too low, then it does not dampen the methane line system enough and the Q increases and the vibration amplitude increases until the propellant line (the spring) — or its mount — fails.
Again, a solution could be to change the spring value of the propellant line so that the natural frequency is not reached. This is how I sought to avoid bad natural frequencies. A high spring value kept the worst natural frequencies higher than the expected vibration of the satellite. Materials selection could also have an effect on the damping of whatever part of my instrument was acting as a spring, and maybe this could also help with Starship. In my case, PC boards tend to have high enough damping to avoid the breaking point.
Would a change of materials to increase damping in the propellant line help with SpaceX’s problem? I don’t know. They need materials that are strong enough under cryogenic conditions.
_____________________
Ray Van Dune wrote: “It is more likely in my opinion that the problem lies in too few top-notch engineers being available and lack of bandwidth to integrate them into a ramping-up development and production process.”
I’m not so sure. I don’t think it is a culture problem, because similar corporate cultures have worked before. I don’t think it is an overwhelmed workforce problem, because SpaceX seems to be well partitioned. I don’t think that the employees are too pressured to launch on time, or better phrased, to launch at a high cadence. I don’t think that it is related to hot staging, although the current design may not be gentle on Starship. I don’t think that a smaller development upper stage would have found this problem, but an expendable ship of this size would have, but then the fix would still take just as long. This is not the first time that Starship has had two spectacular failures in a row, in full view of the public. I do think that fixing this problem in three months (by June, as Robert thinks may happen) is a rapid development solution. Few other projects have been this ramped up for this rate of production in the middle of the development stage.
It may be a problem of lack of imagination, which is a limit humans tend to have, despite our immense imaginations. But I think it is most likely a problem with a lack of good simulation software.
I’m not current on simulation and design software, but I wonder just how well the currently available design packages treat the damping characteristics of the cryogenic oxygen within its propellant tank on the propellant lines passing though the tank. Do the models emulate reality well enough for SpaceX to have found the problem through modeling, or is this one of the factors that just are not yet ready for prime time and are among the reasons that there is just nothing like actual test flights?
Rockets are difficult, as Chuck said, and this one is trying to do a lot of things differently than have been done before, such as getting rid of the months of refurbishment that the reusable Shuttle needed. I agree with MDN; in addition, my vibration professor did not believe in random vibration, but that is what we tested most when I was designing space instruments and building and testing satellites. Diane Wilson is right about the importance of flight testing, but I have performed modal testing with suspended test units (tap them with an instrumented hammer) that were intended to simulate reasonable vibration characteristics in flight. However, this kind of testing is limited, as it would be difficult to perform on Starship at the various propellant levels in the tanks. Is a Starship strong enough to be suspended with propellants in the tanks?
Although SpaceX expects a certain amount of failure, at this point they expect much smaller failures, not loss-of-vehicle failures. They thought that they had already learned and applied their lessons to get to orbit, but it seems that the result of their recent design modifications is similar to their philosophy of removing as many parts as possible and adding back parts that turn out to be necessary after all. As Musk said, if you aren’t adding back some parts, you haven’t removed enough of them. Here, they seem to have done something similar with their version-2 Starship. They made too many changes, and one of them bit them in the butt. Was it the vacuum jacketing? Was it separating out the vacuum-engine feed lines, and they should recombine them all together again?
It might sound cheaper to test bullet type Starships…but that might hide things.
With a single downcomer–and the nose “fins” directly opposite each–Starship seemed well behaved for the most part.
The forward control surfaces were moved closer to the dorsal surface–and closer to each other.
Might that give some sharp peaks of vibration that can propagate back to the engines?
In terms of heat shields—perhaps this could help:
https://phys.org/news/2025-03-nature-ceramic-fiber-aerogels-advance.html