I've got no idea what those guys with what looked and sounded like hand grinders were doing at the bottom of SN-1, before the crane lifted it off the crawler. Maybe some restraints and connections actually have to be abraded away rather than unscrewed, unfastened, and unplugged.
(Feb 25, 2020 07:27 PM)Yazata Wrote: It was exceedingly foggy around sunrise today in Boca.
When the fog finally burned off, the SN-1 tank cylinder had disappeared! It was gone!
It was soon located though, down at the launch area a mile away. They moved it by stealth, under cover of fog.
Mary's back from her trip and is on the job, and she says she has video of its arrival (atop those blue Roll-Lift crawlers) down at the launch area, but she hasn't posted it yet. A snippet:
Right now it seems to be waiting for the Giant Crane to prepare itself to place it atop its launch platform, where the umbilical connections to cryogenic fluids (liquid nitrogen pressurant, fuel, oxidizer) plus electrical and data connections are located.
Edit: Mary reports that the Giant Crane has placed SN-1 atop its base.
YazataFeb 26, 2020 05:51 PM (This post was last modified: Feb 26, 2020 06:36 PM by Yazata.)
(Feb 25, 2020 09:25 PM)C C Wrote: I've got no idea what those guys with what looked and sounded like hand grinders were doing at the bottom of SN-1, before the crane lifted it off the crawler. Maybe some restraints and connections actually have to be abraded away rather than unscrewed, unfastened, and unplugged.
That seems to happen when workers can be seen at the supports supporting the Cylinder atop the Roll Lift crawlers.
I don't know what it was, but my guess is like yours. Perhaps the Cylinder was fixed to the crawler somehow to stabilize it during its road trip. And the easiest way to release it was to just cut it off. Simply a guess.
That grinding sound was apparently just about the last thing they visibly/audibly did before they lifted it.
Here's Mary's video. (It's about 15 minutes.) It starts with the day before yesterday for about the first two minutes, then shows everything in the last video. But Mary cuts out the boring bits and plays the rest in fast motion. (It makes Elon's workers look like they are ants scurrying around, working on Elon time!)
She shows a fleeting closeup of the grinders mentioned above. Stopping the video there and blowing the picture up should show what tools they are using. (Looks like a circular saw?)
Starship SN1 tank preparing for Raptor attachment & static fire
So there's the plan. (I assume that the pressure test will happen too, since the tanks' integrity is implied by a static fire. Besides, road closures all the rest of this week and no sign of a Raptor in Boca yet.) I don't know if they plan to actually fly this one.
He adds:
SN2 tank integration starts this week with much less circumferential pucker. Thanks Fronius!
And that signals that construction of the second Starship prototype is already underway. A new nosecone is visibly taking form and more rings keep appearing.
And a big oops concerning weld quality on SN1. Something that Fronius apparently helped them straighten out:
We had the wrong settings! To make the welds super flat & strong, we're building a heavy duty, custom planisher, but just having the right settings is a major improvement.
This is what I like about SpaceX. How many other companies would freely admit a mistake like that? Maybe part of the explanation is that SpaceX is building its Starships on its own initiative for its own use, and isn't building them for another customer.
And for something entirely different, who knew that you can cast shadows on fog? Very cool shadows, like giant alien bugs? (MR's been expecting them.)
(Feb 25, 2020 09:25 PM)C C Wrote: I've got no idea what those guys with what looked and sounded like hand grinders were doing at the bottom of SN-1, before the crane lifted it off the crawler. Maybe some restraints and connections actually have to be abraded away rather than unscrewed, unfastened, and unplugged.
That seems to happen when workers can be seen at the supports supporting the Cylinder atop the Roll Lift crawlers.
I don't know what it was, but my guess is like yours. Perhaps the Cylinder was fixed to the crawler somehow to stabilize it during its road trip. And the easiest way to release it was to just cut it off. Simply a guess.
That grinding sound was apparently just about the last thing they visibly/audibly did before they lifted it.
Here's Mary's video. (It's about 15 minutes.) It starts with the day before yesterday for about the first two minutes, then shows everything in the last video. But Mary cuts out the boring bits and plays the rest in fast motion. (It makes Elon's workers look like they are ants scurrying around, working on Elon time!)
She shows a fleeting closeup of the grinders mentioned above. Stopping the video there and blowing the picture up should show what tools they are using. (Looks like a circular saw?)
Viewing it close-up, it maybe resembles a hand-grinder with safety guard partially surrounding the disc. Portable abrasive saws that cut metal tend to operate vertically rather than horizontally; but then again I'm only familiar with hubby's choice of playthings. Looked like an inspector peering at the work in one scene, which might suggest scrutiny of surface rather than measuring a cut's angle/length.
Along with the sounds not quite matching, seems to be too many sparks flying around for a rotating wire brush. I don't know why they'd want to spiffy-clean _X_ on the crawler unless welding will be done at _X_ in the future.
Though there's alternatively the mystery of what/why they'd be grinding, too. Removing welds? The workers are using flip-up visor welding helmets rather than ordinary face shields, which might suggest they're recruited to both weld something before the trip and eliminate such bonds afterwards.
That's my uneducated guess as to what was happening.
As to what they plan to do with this Cylinder, flying it doesn't seem to be in the program. Elon's tweeted that they won't be going to three Raptors until SN2. Production Starships will have six, but three will be vacuum optimized and will only be used in space. So three for launch and landing.)
And besides the announced road closure, there's a NOTAM for Saturday night. It says launch and recovery, but that's unlikely. SN1 isn't likely to get off the ground. This is probably only going to be a static rocket engine test. People have been wondering why, and my guess is to check the engine's compatibility with the kind of flight systems that an operational rocket will have, such as control systems and using on-board COPVs to spin up the turbo pumps when the engine starts. And also to test the autogeneous pressurization system where they propose to use bleed-gas from the rocket engine to pressurize the fuel and oxidizer tanks.
Austin Bernard has a photograph of a Raptor engine at Boca that I think was taken recently, so I guess that there is an engine there.
And today is the six month anniversary of Hoppy's triumphant flight. (Seems a lot longer than that... is the whole Earth trapped in Elon's relativistic time-vortex?)
YazataFeb 29, 2020 04:25 AM (This post was last modified: Feb 29, 2020 06:15 AM by Yazata.)
They are pouring concrete to create a floor in preparation to erecting a third giant tent, next to the existing two and the tell-tale giant arches are going up. And they are preparing the soft ground surface with scraping and grading for what may or may not be yet another giant tent (the fourth) next to the just now appearing third one.
Elon just Loves his giant tents. Can't get enough of them! He even presents his giant tents with giant rings! (And Sprung, the tent manufacturer, must love their most high-profile customer.) A marriage made in heaven.
It looks like they are graduating from a junkyard workshop to a real factory, capable of mass producing Starships assembly-line fashion. (Elon says that the current 300 Boca employees will grow to 3,000.) He eventually wants hundreds of Starships.
Edit: Pressure test is underway. It's something very cold (liquid nitrogen I'm guessing) since the cylinder is becoming coated with frost.
The bottom bulkhead appeared to blow out and the whole thing took off precisely like one of the MythBusters 'waterheater rockets'. (Except much bigger.) Don't know how high fragments flew or where it ended up.
Lots of confusion on the Brownsville police scanner.
Instant video (from the two streams) of the explosion here:
Talk on NSF is that the pad had been cleared and roadblocks were up, and no injuries are reported. Mary apparently has video that she hasn't uploaded yet. But she's ok and tweeting.
It appears that it didn't fly nearly as high as I'd feared (1000 feet or more). When the bottom blew, the rest seems to have only risen about half the cylinder's height, then crashed down again and burst with a loud bang. Shrapnel did fly several hundred feet.
They already knew that their welds weren't right and had already decided not to try to fly SN1. But they apparently still wanted to see how the inferior welds did and if they survived the pressure test, to run a static raptor engine fire and a test of the autogenous pressurization system (where bleed gas from the rocket engine pressurizes the tanks). So they got a definite data point: inferior welds like these clearly won't suffice.
Reports are that early work on SN2 continues this morning.
Chris Hadfield, Canada's musical astronaut was watching and retweets Mary's video
Apollo astronaut Rusty Schweikart was watching the streams and also had some comments.
SpacePadreIsle's morning after photo thread is here. Click on the first post to find your way to many more photos. The furthest large fragment that he found was several hundred meters away in a marsh across a slough. All that's left this morning are twisted fragments of steel. ('That'll buff out'.)
Interesting screen shot from LabPadre's stream, appearing to show the moment the bottom blew, pressurized LN2 expelled from the bottom, creating a vacuum in the cylinder above with air pressure beginning to crush it. A fraction of a second later the whole cylinder (minus the bottom) leaped upwards a short distance.
(Feb 29, 2020 06:14 PM)Yazata Wrote: [...] They already knew that their welds weren't right and had already decided not to try to fly SN1. But they apparently still wanted to see how the inferior welds did [...]
That makes it sound better. But just like with that junk-bucket Hoppy, at some point they actually need to luck out with the welds, or it starts looking like excusatory propaganda. "Oh, we're still not trying, couldn't care less. Next time we'll make a deliberate effort."
Feb 25, 2020 09:25 PM
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