News Changes to the SpaceX BFR rocket.
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GLS
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Delay
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2200 UTC
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Links to the official live broadcast (again, SpaceX does not use Youtube for live streams, so those are usually scams)
Live stream of Everyday Astronaut
diogom
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Weather scrub, same time tomorrow
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No interior lights required...
Thunder Chicken
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No cabin heater needed either.
The Draper point where visual incandescence starts is about 1000 deg F, but 304 stainless keeps its strength up to about 1500 deg F, so if this picture is real it may not necessarily be indicative of imminent hull breach or structural failure. But given the burn through seen on the body flaps, it might be. There are also a lot of hot spots indicated on the windward side of the hull where there should be TPS tiles, so it seems that they are failing.
My bet is that when they get a good look at the Starship hull after reentry it will look like an overheated BBQ grill with warping and oxidation. If the sheet steel is riveted to the structural members, the thermal stresses are going to be very large. I would not be surprised if they see lots of rivets failing in shear such that parts of the shell partially or entirely separates from the structural members. At these temperature extremes it is imperative to allow for significant thermal expansion and you can't constrain the shell or structural components. Power boiler furnace casings are usually pinned in place and have sliding pedestals or rollers to support the furnace and allow for expansion without constraint.
Even if the structure isn't a problem, I don't think incandescence / radiation heat transfer will be appreciated by future payloads. A lot of heat is being admitted into the hull. An interior steel lining to serve as a thermal radiation shield might slow down the ingress, but that is also going to increase the temperatures in the hull shell.
This isn't good news if they want to keep Starship's weight down.
Urwumpe
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Its good news for @K_Jameson though - so his heatshield isn't too heavy, SpaceX does not use enough heatshield.
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Thunder Chicken
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Well, it shows that the calculations of all the smart engineers at SpaceX were too optimistic as well, so don't beat yourself up too badly. There might be a reason why something like Starship hasn't been done before - it's really damned hard!Well, I don't see how this is a good newsMy fear is precisely to go overweight, and if Starship has to reinforce the heatshield or the hull, it means that my calculations were too optimistic
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I believe it's all welds, no riveting, for aything structural.
That pic seems to be Flight 4, the one with the melted flap(s).
Thunder Chicken
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Welds can be easily broken by thermal stresses as well. Continuous steel sheets can be torn like paper by thermal stresses. I've seen it happen in practice. It all comes down to whether there is enough compliance for expansion. I'm sure they have analyzed that, but their analysis may have assumed an intact TPS envelope and other things. Parts of the hull are glowing hot, other parts are colder than ice, and it's all expanding and contracting in very unusual and irregular ways. I can't help about thinking about the nosecone geometry and how that is being asymmertically heated - the thermal expansion coupled with the stiffness of a ogive geometry will raise some really horrifying stress patterns.
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Thunder Chicken
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Is this going to be the same basic profile as the last launch? Any effort to recover Starship?
If they catch SuperHeavy again that would indicate that they know what they are doing.
If they catch SuperHeavy again that would indicate that they know what they are doing.
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Approximately yes. There are some more tests of the payload bay and possibly deploying a dummy StarLink like payload.
No.
If they catch SuperHeavy again that would indicate that they know what they are doing.
I am sure most people there know what they are doing. The guy on top might also know it, if he doesn't use his body for disposing dangerous chemicals.
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They have two vessels in the splashdown area, one of them prepared to tow it, and a port in Australia ready to receive it. The hope is the additional reinforcement on this one keeps it intact enough. From there, I suppose learn what they can and scrap on site. On the last one they couldn't tow it but fished out a bunch of stuff.Is this going to be the same basic profile as the last launch? Any effort to recover Starship?
If they catch SuperHeavy again that would indicate that they know what they are doing.
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