The official live feed suddenly froze, no new frames or audio for a few minutes until someone said "We are not waiting for new footage, SN11 is not coming down". I'm amazed by how quickly SN11 came together after SN10: how many rockets does SpaceX have in store?
I was a fan of the “Rapidly Scheduled Non-Ascent” jokes a few weeks ago when Starship’s computers aborted a launch seconds before it would’ve started up.
> Looks like engine 2 had issues on ascent & didn’t reach operating chamber pressure during landing burn, but, in theory, it wasn’t needed.
> Something significant happened shortly after landing burn start. Should know what it was once we can examine the bits later today.
Q: After cleanup, will you roll out SN15? Perhaps BN1 too?
> SN15 rolls to launch pad in a few days. It has hundreds of design improvements across structures, avionics/software & engine.
> Hopefully, one of those improvements covers this problem. If not, then retrofit will add a few more days.
For posterity, here's a link to the full 16 minute official SpaceX launch stream (obviously quickly wrapped up after the failure): https://youtu.be/gjCSJIAKEPM?t=86
>"SN15 rolls to launch pad in a few days. It has hundreds of design improvements across structures, avionics/software & engine."
Yeah at this point everything before SN15 was already completely obsolete, which is why they didn't even bother finishing a few serials before it, and SpaceX only has so much actual physical room to store completed rockets there right now. They may have been getting into "launch it or scrap it" territory and just really wanted to move on, which would explain why this one seemed a touch rushed. Maybe they figured they might as well see if they could get some useful data out of it, and to some extent even launching under foggy and suboptimal conditions was itself a new thing to try. The advantage of a hardware rich cheap dev program, that entire launch probably cost a few million at most.
SN15 is going to be more interesting, the first really major revision towards "finished" status in a while. They're clearly confident they're making progress since they've begun pathfinding for the booster.
> Unless the Raptor engines they flew were also old and obsolete.
They were, SN15+ will use pre-production Raptors instead of prototype ones. A few of the newer engines have already been spotted, they are much cleaner in design and their mounts are rotated compared to the earlier engines (making them incompatible with the rockets that have flown so far)
As well as what others pointed out about these too being prototypes:
>Raptor engines are still expensive.
They stated a while ago the cost of a Raptor was already under $1 million and that they're aiming for <$250k each with 2.0. That'd mean those three cost, at most and prototype status aside, a few million. That's just really not expensive in rocketry, or big machine early development in general. Even ignoring all other investment they can get, they're probably making at least $10-20m+ net income per commercial launch of the F9 at this point. So every single launch could cover multiple Starship tests. It's really wild how frugal it is compared to what everyone has become used to in rocketry, and in turn the kinds of things they can try.
Edit: just for context at the polar opposite end of the scale, "NASA will pay $146 million for each SLS rocket engine" (they need four per launch, and they're all thrown away each time).
Falcon 9 is doing great, but Starlink appears to be eating through all their earnings and well into their cash reserves.
Elon Musk has said "SpaceX needs to pass through a deep chasm of negative cash flow over the next year or so to make Starlink financially viable. Every new satellite constellation in history has gone bankrupt. We hope to be the first that does not." (https://twitter.com/elonmusk/status/1359024384200101888?)lan...
At this point their R&D spending on Starship and Starlink means they're running off constantly raising capital from investors (same as many other startups). When Starlink is generating decent income they're going to be an extremely profitable company, but they're not there yet.
SpaceX will not go bankrupt or have trouble raising money in the near future. Their ace in the hole is doing an IPO. With the current craze people would throw incredible amount of money at them. Talk to investors and everyone is bullish on SpaceX because they have a good moat, strong revenues and growth potential.
To clarify, I wasn't saying they were fully self-funding, just giving some additional context to "not that expensive". Given that they have hordes of investors willing to throw money at them (and for decent reason for once), they'd be foolish to significantly slow bootstrapping through the more capex heavy part of the roadmap rather then doing multiple programs at once, particularly when said programs have real synergy. But if for some odd reason they had to go it alone, it's so cheap and F9 beats others so thoroughly that they probably actually could at this point, which is a wild thing to write about super heavy rocket R&D. It'd make everything take many years longer though, and they'd have to prioritize differently.
I should also mention there is the Artemis HLS down-select coming up in a few weeks where the Lunar Starship should net SpaceX another $2 billion of funding (assuming they're selected).
It's funny that everyone thinks PE is the only source of capital from SpaceX. SpaceX gets most of their income from the government including generous subsidies like those for Starlink.
In fact, SpaceX would not exist without the governmental effort to create a private space industry which has pumped a LOT of money into SpaceX and competitors.
But the conversation is always around investors and not about those who actually made this possible, the American tax payer.
SpaceX does sell a solid chunk of their launches to US government departments, but those departments save on those launches quite a bit - so American taxpayer benefits there.
It's true that SpaceX was helped by NASA after they got their first successful launches of Falcon-1, that help was important and allowed skipping Falcon-5. However that's the regular way American taxpayers - represented by those government departments - operate: they grow markets of new products and services, and then both benefit from new offerings and receive tax from them, while public has more chances for personal enrichment.
In some sense, yes, it's American taxpayer who makes all that - including favorable legal environment - possible; on the other hand, investors are the standard way, the means how that is done. It's odd to see taxpayers and investors as completely opposing entities.
I wonder quite why something like a PT6 costs so much. The development costs are surely paid off by now, and it’s produced in fairly high volume, but it remains expensive. Maybe SpaceX should get into aircraft engines?
Some manufacturers have a monopoly in a certain class of engine thanks to type certification. The certification and liability that comes with it are prohibitively expensive for new comers.
The PT-6 is an example of this; in North America, it stands alone, undisputed king of it's class. What's ridiculous is that turbine engines are simple. More simple than piston engines, and everyone and their dog can build a piston engine.
Too little ascertained facts to share, too big a risk of someone saying something they shouldn't have - like a trade secret, or something covered by exports regulations?
Pretty cool that they already have a buildout until SN20. Interesting. So they’re just pumping it out for data and then a revision comes in C units later with improvements. Very cool. They’re expecting to crash quite a few then. Haha.
It's pretty clear to me that SpaceX has no comprehensive model of how their craft works, or a clear testing methodology; they're just throwing stuff at the wall to see what sticks. They're going to be finding unfortunate surprises in the "Starship" until the day it is taken out of service. It reminds me of how the Space Shuttle was designed. Hope is not a strategy.
SpaceX has a "test as you fly" philosophy. It's the same approach that built the Soviet Union's excellent rockets (including the Soyuz).
Unlike the Soviet Union, SpaceX can afford to fund their version of the "N1" moon rocket: at around $1 million per Raptor engine (and 3 Raptors per Starship hop test) the R&D program is still relatively affordable, even with the failures.
This philosophy is in stark contrast to the SLS (Space Launch System) which after decades of development has only just done a static fire. Also SpaceX's philosophy around the Starship test program is focused on building a factory that can manufacture thousands of Starships vehicles a year.
But I agree on the spectrum between "analysis paralysis" and "reckless" SpaceX is arguably a bit too far towards reckless at the moment.
I hope apparently wasteful R&D program yields better results soon. They need to start testing rapid reuse for Starship to be able to meet its cost goals.
Yeah, Komarov's story was a really bad example of rushing things. Looks like it helped to bring space industry leaders to senses. USSR was infamous for trying to make "victories" by the time of next anniversary of October Revolution, or party gathering, but spaceflights since then weren't rushed with half-baked tech and a human onboard.
Well, obliviously they do have a comprehensive model since they are able to:
1. start the most advanced rocket engines (full-flow staged combustion cycle engines [1])
2. ascend to 10km gradually shutting down (and throttling) engines to keep relatively constant speed while methane and oxygen are depleting
3. switch from vertical ascent to horizontal descent flight profile, and from 10km "fall" (or rather fall/glide) into the 30 meters target of the landing pad
4. reach soft landing (almost accomplished by the SN10)
BTW Roughly only the first two of those items are in the "normal" checklist of any other rocket company for an orbital rocket.
SpaceX is following somewhat Soviet rocket development approach with many testing, which is not a bad thing by itself. It is just different to what we are used with NASA/ULA/et al. SpaceX is also very open with their testing, you can literally see the rocket from 50 meters away, and its launch (from 8km) freely. We obviously have an observational bias here, while not knowing how many failures others have.
start the most advanced rocket engines (full-flow staged combustion cycle engines [1])
Well, not. During SN9 flight, one engine could not be re-lit, so SN9 crash-landed. During SN10 flight, the two engines that were needed for landing were lit, but there was an imbalance in the fuel mixture, one engine burned noticeable more yellow than the other, and now this. You'd think they'd analyze telemetry data from flights and on-ground testing and improve their design, but visibly they don't.
And they are on notice already from the FAA for routinely blowing stuff up near a populated area.
The key parts of SN11 were manufactured before SN9 was launched, obviously it can't incorporate design feedback from that.
SN15 (the next launch) has a tweaked design of engines, but once again they are going to have multiple launches with these specific engines even if data from the first launch suggests some improvements. In fact, they had originally planned to do even more testing with this design (SN12,SN13,SN14 which had a bunch of work already done).
F-1 development included creating a particular debugging technique for rocket engines - bombs were put into chamber and exploded to create instabilities, so engine dampening capabilities were tested.
I wonder if while making Raptors some interesting techniques were created. For F-1 the result was so good the production engines routinely dampened instabilities, so Saturn-V didn't have this kind of problem in flight. Raptors seem to be less developed - of course, they have much higher chamber pressure and efficiency...
They're having no trouble starting the engines on the ground, for launch, like any normal rocket company.
They're having some trouble restarting them on landing, because getting the fuel to flow properly with that dramatic flip in the air is a bit of a challenge, which nobody else has ever attempted.
Yeah, I'm sure they're ignoring telemetry data. They probably just go outside with a few polaroid cameras and capture pics.
I can't tell if you're trolling, or if you're serious? SpaceX does an incredible job of instrumenting their rockets. They do plenty of "on ground testing" of Raptor, but some things can only be tested during flight.
It also rained down toxic debris over a 10 km radius of pristine land. The EPA needs to get involved. It's clear SpaceX doesn't know what they're doing.
The rocket was supposed to be able to blow up like this, that’s why the flight termination system is installed. Also SpaceX has to get certified for launching from Boca Chica which means that all the government agencies that could get involved have already given their permission for this sort of event occurring.
Onboard the fuel is methane (evaporates) and lox(just oxygen). What toxic debris do you imagine rained down?
Who knows better than spacex what they're doing? The EPA?
About the only thing that is really messy is the Tesla battery raining down lithium chunks and whatever else it's made out of. Of course there is some burning plastic and wire that's not great. But it's not really that much stuff.
RUD was <1km, likely around 100-250m (speculation) from the flash in stream. Debris probably at most a 1km radius around, and this is land they bought and will clean up (obviously).
Wow, I wonder how much damage there will be to the launch complex - some of those chunks of debris are enormous. Hard to imagine that nothing important was hit by falling parts.
What is interesting is that, if you watch the views of the engines during ascension, there are flames around the base of the engine(s) (only one? somewhat hard to tell) starting at T+00:14 and continuing off and on until around the first engine cutoff time (T+02:10).
Tim Dodd (Everyday Astronaut) and his group of friends had gotten permission to put a bunch of camera equipment right near the landing zone. They were psyched to have up-close footage of SN11 landing, or at least trying. They setup apparently $20,000 worth of cameras down there.
The last images those cameras broadcast were of large pieces of debris falling out of the foggy sky, smashing into the ground around the camera, splashing up dirt, and then everything went dead. I feel bad for the guy, but the look on his face as he realizes what's happening is priceless. I donated $5 just for that.
Just to clarify, his immediate comment that "they blew it out of the sky" is (at best) pure speculation.
If you want to watch third-party livestreams, I usually recommend the NASASpaceFlight streams [1] that have more fact-based narration. They also had debris hitting their camera, but it seems to have survived.
Are those tanks around the landing site full of anything volatile? Seems odd to me to plan on landing a highly experimental rocket next to equipment like that. I am assuming the whole landing site is miles away from people.
Conversely, I find it odd that these experimental ships have failed that many times without having neded to autodestruct a single one. The mechanism must be there, but seems like it has not been used.
One question I have that is tangentially related is why salaries and total comp is so bad at SpaceX? I'm a staff engineer at FANG with some highly relevant skills and would love to work at SpaceX, but the comp friends that worked their told me about was a dealbreaker at 2/3 of what I currently make. Asking because SpaceX employees might be reading this and could share some insight here. Is it possible to get comparable comp?
You could probably also get 2x what you're making now in finance. Why do people work for FAANG companies when they could make so much more in finance? A mix of culture, technology, perks, and prestige. Why would someone work for SpaceX for 2/3 the salary? Because they're putting rockets in orbit.
The other factor is that I don't think SpaceX see software as a differentiator. They have talented software engineers, sure, but a lot will be a very different type of software engineering to the typical FAANG sort, lots more real-time and embedded software. I believe their main piece of non-real-time/embedded software is their inventory/work management application which is all on the Microsoft stack. My gut feeling, could be wrong, is that your average .NET dev makes less than your average dev at a FAANG company. The market may just not need the higher salaries.
I would imagine it’s because you are working with rockets and satellites that actually go into space. Personally I’d gladly make the trade off with 2/3 less comp compared to FANG in order to work with Falcon 9, Starlink, and Starship. And considering how many capable engineers SpaceX has I think there are more top tier engineers willing to make that trade off.
Same reason Tesla talks a big game but has skipped their 401(k) match for three straight years. If they can get the people they need for less $$$, they will.
Not sure why you're being downvoted, but yes, comp is very low at SpaceX for given level of experience.
I know a number of people working in engineering in SpaceX (as in, designing the rockets or modules), and most of them are making between 50k and 90k, despite having PhDs or years of experience in aerospace engineering. To put the salary in perspective, a few of these people took a pay cut when they left JPL to work for SpaceX.
They work at SpaceX because they find the work exciting and rewarding, but if you're in it for the money you'll have to work at one of their competitors.
That methane would have been released to atmosphere had SpaceX not purchased it. Methane is a byproduct of oil extraction in many places, and two years ago the law in the US stipulating that the methane must be recovered was rescinded. I don't know why the EPA did that, methane is a potent greenhouse gas.
So what is actually happening, these Starships are burning the methane into CO2, which is a far less potent greenhouse gas than is methane.
>A rocket doesn't have eyes, and they get all the data through telemetry anyway.
Well sure, but people still have eyes. You would want to visually see what's happening with your rocket test wouldn't you? It just makes no sense why they didn't scrub for a few hours. Especially given the abundance of caution SpaceX has always shown with that.
I also noticed (and this could be entirely unrelated) that during the ascent one of the engines was burning a bit richer than the rest. Notice that the flame is quite a bit more orange during ascent: https://youtu.be/bDL-ZMRHYrE?t=8208 It becomes a bit more noticeable once they get higher in the atmosphere and the cones expand.
Given the onset of SN15-20, I wonder if SN11 is considered obsolete and was deliberately launched under adverse (yet FAA-approved) conditions. Better to launch and see what happens (fog, rapid turnaround, etc) than just dismantle it in a boring manner.
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[ 5.5 ms ] story [ 197 ms ] threadhttps://twitter.com/_brendan_lewis/status/137556748395276288...
The next big milestones are SN15 launch (major upgrades in that version onward) and the booster launch (hasn't been tried yet).
They are hoping to get the 2 stage to orbit this summer, so probably after at least 4 more tests.
That link is the best coverage of the next flights SN15, SN16, SN17 and BN1, BN2, BN3. The aspirational schedule has been confirmed by Elon
> At least the crater is in the right place!
> Looks like engine 2 had issues on ascent & didn’t reach operating chamber pressure during landing burn, but, in theory, it wasn’t needed.
> Something significant happened shortly after landing burn start. Should know what it was once we can examine the bits later today.
Q: After cleanup, will you roll out SN15? Perhaps BN1 too?
> SN15 rolls to launch pad in a few days. It has hundreds of design improvements across structures, avionics/software & engine.
> Hopefully, one of those improvements covers this problem. If not, then retrofit will add a few more days.
For posterity, here's a link to the full 16 minute official SpaceX launch stream (obviously quickly wrapped up after the failure): https://youtu.be/gjCSJIAKEPM?t=86
Yeah at this point everything before SN15 was already completely obsolete, which is why they didn't even bother finishing a few serials before it, and SpaceX only has so much actual physical room to store completed rockets there right now. They may have been getting into "launch it or scrap it" territory and just really wanted to move on, which would explain why this one seemed a touch rushed. Maybe they figured they might as well see if they could get some useful data out of it, and to some extent even launching under foggy and suboptimal conditions was itself a new thing to try. The advantage of a hardware rich cheap dev program, that entire launch probably cost a few million at most.
SN15 is going to be more interesting, the first really major revision towards "finished" status in a while. They're clearly confident they're making progress since they've begun pathfinding for the booster.
Unless the Raptor engines they flew were also old and obsolete.
They were, SN15+ will use pre-production Raptors instead of prototype ones. A few of the newer engines have already been spotted, they are much cleaner in design and their mounts are rotated compared to the earlier engines (making them incompatible with the rockets that have flown so far)
>Raptor engines are still expensive.
They stated a while ago the cost of a Raptor was already under $1 million and that they're aiming for <$250k each with 2.0. That'd mean those three cost, at most and prototype status aside, a few million. That's just really not expensive in rocketry, or big machine early development in general. Even ignoring all other investment they can get, they're probably making at least $10-20m+ net income per commercial launch of the F9 at this point. So every single launch could cover multiple Starship tests. It's really wild how frugal it is compared to what everyone has become used to in rocketry, and in turn the kinds of things they can try.
Edit: just for context at the polar opposite end of the scale, "NASA will pay $146 million for each SLS rocket engine" (they need four per launch, and they're all thrown away each time).
https://arstechnica.com/science/2020/05/nasa-will-pay-a-stag...
Elon Musk has said "SpaceX needs to pass through a deep chasm of negative cash flow over the next year or so to make Starlink financially viable. Every new satellite constellation in history has gone bankrupt. We hope to be the first that does not." (https://twitter.com/elonmusk/status/1359024384200101888?)lan...
At this point their R&D spending on Starship and Starlink means they're running off constantly raising capital from investors (same as many other startups). When Starlink is generating decent income they're going to be an extremely profitable company, but they're not there yet.
For those unfamiliar, here's a great overview of the Artemis HLS landing systems: https://youtu.be/WSg5UfFM7NY?t=47
A private company developing a Super Heavy Lift Mars/Moon rocket and streaming the monthly tests online. Very exciting times.
In fact, SpaceX would not exist without the governmental effort to create a private space industry which has pumped a LOT of money into SpaceX and competitors.
But the conversation is always around investors and not about those who actually made this possible, the American tax payer.
It's true that SpaceX was helped by NASA after they got their first successful launches of Falcon-1, that help was important and allowed skipping Falcon-5. However that's the regular way American taxpayers - represented by those government departments - operate: they grow markets of new products and services, and then both benefit from new offerings and receive tax from them, while public has more chances for personal enrichment.
In some sense, yes, it's American taxpayer who makes all that - including favorable legal environment - possible; on the other hand, investors are the standard way, the means how that is done. It's odd to see taxpayers and investors as completely opposing entities.
That said, SpaceX has made a habit of defying my expectations in the past.
The PT-6 is an example of this; in North America, it stands alone, undisputed king of it's class. What's ridiculous is that turbine engines are simple. More simple than piston engines, and everyone and their dog can build a piston engine.
why not talk about the failure's possible causes for 3 hours? would be more interesting than not
Unlike the Soviet Union, SpaceX can afford to fund their version of the "N1" moon rocket: at around $1 million per Raptor engine (and 3 Raptors per Starship hop test) the R&D program is still relatively affordable, even with the failures.
This philosophy is in stark contrast to the SLS (Space Launch System) which after decades of development has only just done a static fire. Also SpaceX's philosophy around the Starship test program is focused on building a factory that can manufacture thousands of Starships vehicles a year.
But I agree on the spectrum between "analysis paralysis" and "reckless" SpaceX is arguably a bit too far towards reckless at the moment.
I hope apparently wasteful R&D program yields better results soon. They need to start testing rapid reuse for Starship to be able to meet its cost goals.
1. start the most advanced rocket engines (full-flow staged combustion cycle engines [1])
2. ascend to 10km gradually shutting down (and throttling) engines to keep relatively constant speed while methane and oxygen are depleting
3. switch from vertical ascent to horizontal descent flight profile, and from 10km "fall" (or rather fall/glide) into the 30 meters target of the landing pad
4. reach soft landing (almost accomplished by the SN10)
BTW Roughly only the first two of those items are in the "normal" checklist of any other rocket company for an orbital rocket.
SpaceX is following somewhat Soviet rocket development approach with many testing, which is not a bad thing by itself. It is just different to what we are used with NASA/ULA/et al. SpaceX is also very open with their testing, you can literally see the rocket from 50 meters away, and its launch (from 8km) freely. We obviously have an observational bias here, while not knowing how many failures others have.
[1] https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-f...
Well, not. During SN9 flight, one engine could not be re-lit, so SN9 crash-landed. During SN10 flight, the two engines that were needed for landing were lit, but there was an imbalance in the fuel mixture, one engine burned noticeable more yellow than the other, and now this. You'd think they'd analyze telemetry data from flights and on-ground testing and improve their design, but visibly they don't.
And they are on notice already from the FAA for routinely blowing stuff up near a populated area.
The lessons from SN9 and SN10 are probably incorporated SN20 or even later version. (Or corresponding versions of Raptor engines.)
SN15 (the next launch) has a tweaked design of engines, but once again they are going to have multiple launches with these specific engines even if data from the first launch suggests some improvements. In fact, they had originally planned to do even more testing with this design (SN12,SN13,SN14 which had a bunch of work already done).
I wonder if while making Raptors some interesting techniques were created. For F-1 the result was so good the production engines routinely dampened instabilities, so Saturn-V didn't have this kind of problem in flight. Raptors seem to be less developed - of course, they have much higher chamber pressure and efficiency...
They're having some trouble restarting them on landing, because getting the fuel to flow properly with that dramatic flip in the air is a bit of a challenge, which nobody else has ever attempted.
I can't tell if you're trolling, or if you're serious? SpaceX does an incredible job of instrumenting their rockets. They do plenty of "on ground testing" of Raptor, but some things can only be tested during flight.
FAA gives launch approval knowing full well what can, and does, go wrong. It’s FAA’s job to deny on the slightest justification of risk notice.
Edit: Guess it can https://twitter.com/thesheetztweetz/status/13769101481160826...
Do you have a citation for the toxicity or the range of the debris?
I haven't seen reporting on either of those facts, so I'd love to learn more.
[0] https://twitter.com/spacepadreisle/status/137689832067794124...
In this video you can hear engines start then an immediate explosion https://mobile.twitter.com/TheFavoritist/status/137689513012...
Possible the burn started late right above the ground. But I reckon we would have seen a larger explosion on the cameras in that case.
https://youtu.be/4qS5Vhz8VJo
The last images those cameras broadcast were of large pieces of debris falling out of the foggy sky, smashing into the ground around the camera, splashing up dirt, and then everything went dead. I feel bad for the guy, but the look on his face as he realizes what's happening is priceless. I donated $5 just for that.
Edit: Here's the moment - https://www.youtube.com/watch?v=myVvmb2dF9U&t=2h19m32s
If you want to watch third-party livestreams, I usually recommend the NASASpaceFlight streams [1] that have more fact-based narration. They also had debris hitting their camera, but it seems to have survived.
[1] https://www.youtube.com/channel/UCSUu1lih2RifWkKtDOJdsBA/vid...
The other factor is that I don't think SpaceX see software as a differentiator. They have talented software engineers, sure, but a lot will be a very different type of software engineering to the typical FAANG sort, lots more real-time and embedded software. I believe their main piece of non-real-time/embedded software is their inventory/work management application which is all on the Microsoft stack. My gut feeling, could be wrong, is that your average .NET dev makes less than your average dev at a FAANG company. The market may just not need the higher salaries.
I know a number of people working in engineering in SpaceX (as in, designing the rockets or modules), and most of them are making between 50k and 90k, despite having PhDs or years of experience in aerospace engineering. To put the salary in perspective, a few of these people took a pay cut when they left JPL to work for SpaceX.
They work at SpaceX because they find the work exciting and rewarding, but if you're in it for the money you'll have to work at one of their competitors.
So what is actually happening, these Starships are burning the methane into CO2, which is a far less potent greenhouse gas than is methane.
Well sure, but people still have eyes. You would want to visually see what's happening with your rocket test wouldn't you? It just makes no sense why they didn't scrub for a few hours. Especially given the abundance of caution SpaceX has always shown with that.
Not really? You'd just see it explode, not much information to be gained from that.
> It just makes no sense why they didn't scrub for a few hours for it to clear out
Winds (which are much more dangerous for a rocket than fog) were forecasted to pick up later in the day.
SpaceX treats customer payloads with an abundance of caution, internal tests... not so much.
I also noticed (and this could be entirely unrelated) that during the ascent one of the engines was burning a bit richer than the rest. Notice that the flame is quite a bit more orange during ascent: https://youtu.be/bDL-ZMRHYrE?t=8208 It becomes a bit more noticeable once they get higher in the atmosphere and the cones expand.
Even with all that fog.