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The latest NSF video shows something interesting; at the OLM a crane lowers a vertical column of rebar that is estimated to be about 100 ft tall down into the excavated hole below the OLM. No doubt there will be multiple such rebar columns. They will of course be filled with concrete and then provide a solid foundation for the water cooled steel flame diverter plate system. I wonder how long a 100 ft column of concrete takes to cure?
You can see the rebar column on the right side of this image. The yellow crane is lifting it up, over, and down into the inside of the OLM.
You can see the rebar column on the right side of this image. The yellow crane is lifting it up, over, and down into the inside of the OLM.
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In fact, they're well along the way with those columns. I think there are two between each leg and then more in the center.
I believe the issue is extracting heat from the exothermic reaction that takes place as the concrete is curing. Thus, I expect the overall cure time is much more dependent on the volume-to-surface area ratio of a given structure, as well as the heat transfer coefficient of what's surrounding it.
So for a cylinder of concrete like they appear to be pouring into a shaft they are lowering that rebar in to, given a fixed diameter, I'd think that a 20' column and a 100' column would cure at roughly the same time.
This is ignoring that a shorter cylinder has a slightly greater surface-to-volume ratio (due to the ends), and thus would be slightly faster, but for the sake of this discussion not likely significant... we aren't talking 2-3x as long just because it's a long cylinder. This also ignores getting deep enough into the earth crust to get warmer... I don't know enough about geology to know at which depth that would become a factor.
Now if the issue was a larger diameter column, then I could see that becoming significant... the volume goes up with the square of the diameter, whereas surface area rises only linearly with the diameter. Once the surface area becomes insufficient to allow for sufficient passive heat radiation, active cooling is often used. The Hoover dam for instance (not round, but very thick in cross-section) used internal piping cast within the concrete with fluid pumped through it to act as a thermal cooling structure, otherwise it would have taken many years to cure (and I think would have risked damage from heat build up).
Thanks for posting that, I’ve missed the regular Ring Watchers infographics, they are very well done.
From the latest NSF video, the Rocket Garden is almost full but it looks like there is room for one or two more vehicles.
Intense activity at Stage Zero.
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Starship is pushing $5B to date, though that's not as impressive a number when one considers what Jeff's been dumping into Blue (or obviously, what Congress dumps into SLS). SX also has some mega contracts that make $5B pretty manageable.
That number appears to include the launch facilities as well, not just the vehicle:
According to article, they aren't sure what the breakdown is:
It also says that $5 billion would be the number by end of year, and we're about halfway through, and the estimate was $2B spent this year, so we the number is probably really about $4B to date...
Unbelievable how much SpaceX has accomplished with the money spent in comparison to traditional aerospace companies and NASA.
Even more so when you factor in that they have built the first ever reusable rocket factory!
An anecdote from Corey Steuben at Monroe Associates seems appropriate here. He would talk to folks he knew at legacy auto and ask how things were going. They'd talk about their efforts to advance their careers within the company. He would also ask the same of folks at Tesla. They'd talk about the technology and the projects that the company was pursuing. I'm sure the exact same thing applies at SpaceX versus legacy aerospace. Elon's employees have joined his technology crusades. I just hope they don't get old and cautious, believing that the lessons they've learned are The Answer.
Latest RGV flyover.
Water deluge system is progressing. The large diameter piping exits just to the left (in this image) of the 4 hot dog-style water tanks and I think will be connected to the two large elbow pieces protruding above the surface at the far left. From that point the piping is subsurface over to the OLM where it will be connected to the “shower head” perforated steel pieces.
Looking down on the inside of the OLM it appears that the pilings are installed and the pad has been resurfaced.
Water deluge system is progressing. The large diameter piping exits just to the left (in this image) of the 4 hot dog-style water tanks and I think will be connected to the two large elbow pieces protruding above the surface at the far left. From that point the piping is subsurface over to the OLM where it will be connected to the “shower head” perforated steel pieces.
Looking down on the inside of the OLM it appears that the pilings are installed and the pad has been resurfaced.
Road closure scheduled for next Monday. Speculation is that there will be a static fire of S25.
Tanked, sat, depressurized, then detanked. I was happy to see so much ground support equipment working after The Event.
In case anyone missed it, SpaceX performed a “flight-like chill and spin of the Raptor engine pumps” last Wednesday (what is commonly referred to as a “spin prime test”). This screen capture is from the latest Marcus House video. He speculates that a full static fire of S25 could occur next week.
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