Scivillage.com Casual Discussion Science Forum

Mary reports that Cameron county has announced a road closure for tomorrow, Jan 9.

https://twitter.com/BocaChicaGal/status/...2137637888

http://www.cameroncounty.us/space-x/

So maybe they are ready to pressure test what Mary calls the "bopper" (baby popper) and others are calling "the egg".

The latest consensus seems to be that it's a test article and will be tested to destruction. If that's correct they will pressurize it until it bursts. That way they will know what its limits are and will have some idea what kind of safety margins they will have with planned operational pressurizations.

Actually, this "egg" may not be all that far off from the planned size of the Starship LOX tank.

Here's a video of "bopper" (baby popper) by Bocachicagal/Mary

https://twitter.com/NASASpaceflight/stat...0626319363

The video also shows them putting the end walls on the Giant Tent. (Still no signs of a second Giant Tent.) There is a second smaller tent going up, similar to the existing ring machine tent.

Mary reports that a RollLift crawler has started crawling in the direction of the "bopper"/"egg".

Others of Mary's ultradetailed photos have shown what's going into the new smaller tent. It's a Flow Waterjet metal cutting machine and associated secondary machinery. It isn't clear if it's a high-end off the shelf model or a custom bespoke machine.

These machines pump water at super high pressure into a special nozzle that shrinks the flow down to the size of a hair, in so doing accelerating the water's speed to about mach 4. Then very finely divided garnet dust is sucked into the flow by Venturi effects, resulting in a water jet the diameter of a human hair that can cut through almost anything (like steel a foot thick). The tiny diameter can be moved very precisely on 3-D x-y-z coordinates by computer control enabling cutting very precise parts. Flow Waterjet is a US company from the Seattle area started by a group of former Boeing engineers.

https://www.flowwaterjet.com/Learn/How-W...spx#basics

The NSF engineers are impressed and say that SpaceX isn't fooling around here.

What's more, one of the secondary machines seems to be a thing that recovers the garnet abrasive from the after-cutting wastewater. The engineers don't think that they would have installed one of those unless they plan to do a lot of cutting.

Edit: Bopper is on the crawler and moving down the road to the launch area.

https://twitter.com/BocaChicaGal/status/...0343164928

Lab Padre's Live-feed here:

https://www.youtube.com/watch?v=2d8l_0w2VKM

Edit 2: Bopper is at the launch area. Dunno what else, if anything is going to happen with it today. Some suggestion that they might pressurize it this evening.

https://twitter.com/SpacePadreIsle/statu...0507947009

Edit 3:

They are still busily attaching plumbing and electrical wiring to the Bopper. Workers are swarming around. So I'm guessing no pressure test today.

And it was inevitable... every man knows that there isn't a problem on Earth that can't be fixed with duct tape!!



Edit 4: Spacepadreisle just spoke to SpaceX security and they told him they still plan to pressurize it tonight. Maybe in the wee hours. (Elon never sleeps and neither do his employees, I guess...)

Spacepadreisle has the best live-stream going at the moment, here:

https://www.youtube.com/watch?v=QKdLOCGh5aY

Edit 5: SpacePadreIsle has finally been told that the pad area is being cleared and he has to get outta Dodge. So his livestream is currently off. It may come back if he sets up outside the exclusion zone.

But LabPadre's stream is still on from further away.

https://www.youtube.com/watch?v=2d8l_0w2VKM

I went to sleep last night before they had pressurized the Bopper (baby popper). Here's a video of what happened (from LabPadre's stream):

https://youtu.be/0JkTvfMSHu4

First off, the failure of the tank was expected since it was intended to be a 'test to destruction'. They wanted to see what the upper limits on these particular construction methods were.

The bursting of the tank wasn't nearly as spectacular as Poppy's since this time they were pressurizing it with water, which doesn't BLEVE like liquid nitrogen does. Plus, the top dome was tied down this time so that it wouldn't fly off.

Nobody (outside SpaceX) is sure what the pressure was when the tank burst or whether it met expectations.

........................................................................................

Edit: That is no longer accurate. Everyone who pays attention knows. Straight from Elon, replying to Mary, Tim Dodd and NSF...

"Dome to barrel weld made it to 7.1 bar, which is pretty good as ~6 bar is needed for orbital flight. With more precise parts & better welding conditions, we should reach ~8.5 bar, which is the 1.4 factor of safety needed for crewed flight."

https://twitter.com/elonmusk/status/1215719463913345024

This is one reason why everyone loves SpaceX. They tell you. They let Mary watch and photograph everything. Blu or Boeing would treat the information like a state secret and wouldn't let any outsiders within miles. If you found out the test pressure or the manufacturing techniques that Mary documents every day, they would probably shoot you. That's how things are traditionally done in the rocket industry, which started with nuclear ICBMs I guess. But Elon's certifiably crazy and one of his motives is to make everyone excited about space travel again.

.......................................................................................

Mary's morning photo of the Bopper. The top dome looks partially collapsed. That isn't where the welds failed though, judging from the video above. The failure looked to be simultaneous around the whole circumference of where the dome mates with the ring. I'm guessing that the crunching came as a result of the rapid pressure change. (If the thing is completely filled with pressurized water, and the water is suddenly escaping around the circumference, that could create a vacuum at the top as levels fall.) You can see the yellow tie-downs to keep the lid from flying off.



Somebody leaked this video filmed from inside the Bopper last night:

https://youtu.be/O4RLOo6bchU

Mary reports that they have removed the imploded top dome from the Bopper.

https://twitter.com/BocaChicaGal/status/...9120551946

And two large cranes have moved into a position suggesting that construction of the anticipated second Giant Tent might be about to begin alongside the first one. (Edit: Confirmed. The first two arches are up for the second Giant Tent.)

Plus... at least one more of the smaller tents is going up.

Somebody remarked that Elon must have gotten a quantity discount on Sprung structures. Which probably isn't far from the truth. He's probably their biggest and certainly their most high-profile customer. Just his choosing their structures for his Spaceship Factory (being watched all around the world) is probably worth its weight in marketing gold. 

Poppy's forlorn nose is still there, standing like a monument. (SpaceX has the first Falcon 9 they ever successfully landed standing outside their Hawthorne headquarters.) Everyone is pretty much agreed that Poppy's nose is too crudely constructed to be a viable nose for the follow-on Starships. So it will probably sit there until/unless it's scrapped.

Foggy shot from Lab Padre's stream:



And there's newly arrived structural steel that may (or may not) be destined to be a large overhead bridge crane inside the Giant Tent. (Like in the crane manufacturer's photo below, but probably quite a bit bigger.)



Interesting that since November 20, when Poppy blew up, there's been no sign of a new spaceship starting. There have been experiments with fuel-tank bulkheads and with fabricating tanks. But almost two months after Poppy's demise, they still seem focused on facilities and manufacturing techniques.

But Elon suggests that when the new SN1 starts, it will progress very quickly. Many parts will already be fabricated and are waiting, there's the new ring machine to make rings, along with new and very precise computer controlled metal cutting and welding machines.

Unfortunately for us, much of this will happen inside the Giant Tents and out of view. People have suggested on twitter to Elon that Mary be appointed SpaceX's official archivist, documenting the initial history of the spaceships that may someday take humanity throughout the Solar System. There will be lots of historical interest in that. But no reply as far as I know.

(Jan 15, 2020 09:49 PM)Yazata Wrote: [ -> ]Interesting that since November 20, when Poppy blew up, there's been no sign of a new spaceship starting. There have been experiments with fuel-tank bulkheads and with fabricating tanks. But almost two months after Poppy's demise, they still seem focused on facilities and manufacturing techniques.

They may or may not be making some individual parts. It's hard to distinguish between what's for test and what's for flight. They might not even know themselves. It all depends on how well the things they make pass inspection. Pass - it has a chance of flying. Fail - off to the scrap-yard. Speaking of the scrap-yard, they recently cut up the 'UFO portal' ring for scrap. (I think that the hole cutting was simply a test for prospective new hires, performed on a ring they had already decided to scrap.) And the fuel tank bulkhead that they shipped from Cocoa FL to Boca is now in the scrapyard. Guess it didn't pass inspection and they decided not to use it. 

They have also started welding individual rings around their circumference into double rings. (Again, hard to know whether it's for real or whether they are just perfecting their welding technique.)

Elon just posted this photo on twitter. He says that the ball on the left is Starship's LOX header tank, while the cone on the right is Starship's tippy-top nose. (These may or may not end up on SN1)

Welds seem to be a lot better appearance-wise, although who am I to judge minus getting up real close. Plus, looks surely don't mean squat minus an X-ray or whatever they have to do, to verify adequate penetration. (if only they were smart-material stainless steel objects that could issue noises.)

(Jan 17, 2020 03:03 AM)C C Wrote: [ -> ]Welds seem to be a lot better appearance-wise, although who am I to judge minus getting up real close. Plus, looks surely don't mean squat minus an X-ray or whatever they have to do, to verify adequate penetration. (if only they were smart-material stainless steel objects that could issue noises.)

I think that they are x-raying most of the welds. And given that they are putting in automated robot welding (for the rings at any rate), they aren't going to weld most of it by hand. Maybe just specialty hard-to-craft parts like the header tank balls, the nose cone and the fuel tank domes.

But yeah, the welds had to get better. I think that part of the reason for bad welds on Mk.1/Poppy was that the plates they were welding didn't fit very well. Hence the importance of the computerized metal cutting machines.

Because it's Texas, part II:

A video tour of Boca Chica on extremely high-tech transportation. (Nope, not Teslas.) Complete with built-in intelligence (self steering), able to reproduce more of themselves at no cost to their owner and able to fuel themselves on grass! And they are great off-road vehicles!

https://www.youtube.com/watch?time_conti...e=emb_logo

They start out by Stargate. (The grey building, which isn't SpaceX but rather the U. of Texas. UT has some kind of cooperation agreement with SX.)

Then you can see the early stages of some kind of large metal framework structure going up near the west end of the Giant Tent. Unclear what it will turn out being. There's speculation that it will be a tall Vertical Assembly Building, probably taller than the existing one at the other side of the Giant Tent . If so, they will likely assemble Starships in cylindrical segments in the Giant Tent, then stack them and weld them together in the Vertical Assembly Building (if that's what it really is).

They circle around to the far side of the site and show you the scrapyard area. They ride down into little Boca Chica Village. Emerging back on the beach road, they've passed the parabolic antennas (that SpaceX already uses to control its Starlinks, as well as being on hand for upcoming Boca Chica stuff).

Their vehicles speed up to a trot and even a gallop at times to cover the mile or so down to the launch area. They pass the tank farm and Hoppy, right by the road. Then the landing pad with shipping containers on it, and finally the Superheavy launch area, which is just bare dirt at this point.

Then some surprisingly rugged little overgrown sand dunes and finally the beach.

The new Vertical Assembly Building (maybe?) is coming along rapidly, just to the west of the Giant Tent (the direction of Stargate and opposite from the launch area). Unclear what the final plan for this is, where the doors will be, how big they will be etc. Speculation is that it will go a lot higher than it is now, high enough that a fully stacked Superheavy can fit inside vertically. This clarifies what all the ceaseless earth grading and concrete pouring was about in this area: Flooring and foundations for this (maybe) VAB.

Three arches of the second Giant Tent are visible to the left, with the current (and apparently too small) vertical building the grey presence behind. (That's where the ball and the cone are.) There are at least two smaller (but still big) Sprung tents going up elsewhere around the site. They seem to be gathering the heavy coils of stainless that are delivered from the steel mill in one of the new ones, just behind Stargate.

In other news, a large flatbed was seen delivering what looks like a big fixed Tesla battery to the solar power farm by Boca Chica Village and the parabolic dishes. I believe that Elon plans to run his spaceship factory off electricity they generate themselves.

Photo by Austin Bernard (another of the surprisingly talented locals who has turned himself into a very good spaceship construction photographer):



Edit: Mary's ultra-detailed close-ups of the new (probably) VAB shows gussets for new diagonal structural members, suggesting that the building is indeed going higher.

The door seems like it will be facing away from the road (to the right in the photo above, where the photo was taken), at about a 90 degree angle to the door of the first giant tent. So if the rockets are built in cylindrical sections on an assembly line in the giant tent, they can come out and hang a left into this VAB where they will be stacked. It's expected that there will be a really large bridge crane atop this new building that can lift an entire completed vehicle off its mount and place it atop a crawler for its trip to the beach.

Speculation (by NSF member Nevyn 72) is that when the second Giant Tent nears completion, we may see a second VAB built opposite this one, with its door facing the door of this one and the road. Sections could emerge from a second assembly line in the second Giant Tent, and hang a right to be stacked in the second VAB. So the factory could be building more than one vehicle at a time, maybe a Starship and a Superheavy, or a Starship and a specialized orbital fuel tanker Starship, at once. Or both assembly lines could be directed at completing one vehicle faster.

Somehow the symmetry of it appeals to me and it sounds like something that Elon would do.

More tooling is arriving at Boca Chica. This time it's something called a 'press-brake'. This is a big machine designed to bend steel precisely.

(Amazing the things you learn watching them build spaceships.)

Something like this:

https://www.e-ci.com/autoform-series-press-brakes

From LabPadre's stream:



Elon was at Cape Canaveral yesterday for the In-Flight Abort test. Today he's been spotted several times in Boca Chica.