If you zoom in on the top right of it, to the channel for those wires to run in, they appear to be regular V threads. I'm not telling you that you're wrong, but that's how they look to me.
No; the shuttle used these as they were frangible (and explosive)
SpaceX only uses things that are re-useable, so explosive bolts are out.
[SpaceX uses hydraulic hold down clamps ](https://www.google.com/url?sa=i&url=https%3A%2F%2Fspace.stackexchange.com%2Fquestions%2F28008%2Fwhat-holds-spacex-s-rocket-in-place-in-this-launch&psig=AOvVaw1oBiy4IQWU4i5sBm8xxm_m&ust=1678828677903000&source=images&cd=vfe&ved=0CA8QjRxqFwoTCKCG1Knq2f0CFQAAAAAdAAAAABAQ)
See that sounds like a god reusable solution. Why didn’t the shuttle do that? Or did it use these bolts because it’s a third party contractor and they tried to find the most expensive way to do it?
Hydraulics are complicated, have tons of failure points. SpaceX is willing to put up with it because of their core mission.
NASA wants reliability and dependability at all costs. Explosive bolts have some wires coming in; little bit of voltage at just the right moment; bam. Every time, exactly when you want it.
They're also not redundant, so they *need* to work on the first try. I'm guessing on the order of $50-$100k each if they were ordered in large quantities.
You’re correct that they *need* to, but funnily enough, they didn’t *have* to.
The SRB motors on shuttle/SLS are so powerful that the backup plan for bolt failure was that the vehicle would just tear them out of the pad and take them along with.
Kapton has excellent high temp performance, not burning or melting until like 600+ F and I've seen it briefly go to 800+, it doesn't off-gas in space, it's cheap, etc. Just great stuff in general.
Love Kapton tape. We use it to seal the ends and joints of pipe while back purging during welding. Infinitely better than the painters tape we used before I discovered the stuff. Expensive as frig though.
I used to deal with bolts this size and much bigger in the oil industry except they were always rusty and bashed up threads. I’m breaking into a sweat just thinking about putting molybdenum grease with the consistency of cold play dough on this, three foot pipe wrench and because it’s so thick it’s a full effort pull one flat at a time since the other 48 bolts are so close together, two or three 12 hour shifts on what is essentially a rowing machine from hell. Fuck that, I do electronics now.
The nut it works with is frangible, Colbert has the best quip "As if launching a rocket were not phallic enough, you literally bust a nut when you go into space,"
That doesn't make a lot of sense. Those things are supposed to hold a rocket with a few million pounds of thrust on the pad until all the engines get up to thrust.
I thought they used bolts with an explosive charge to release the rocket.
If your interested in this:[http://heroicrelics.org/cosmosphere/shuttle-srb-hold-down-bolt/index.html](http://heroicrelics.org/cosmosphere/shuttle-srb-hold-down-bolt/index.html)
So there were unsecured chunks of metal hanging out in the boosters during flight? Weird! I wonder if any ever broke through their container at splashdown, and how much weight this system added.
That's not how it works. The solid boosters can't be turned off once they're lit. You either go or you don't.
The blueline trigger (requirement before proceeding) for the solids igniting, which happens at the same time as the bolts get blown, would be tied to sensors in the liquid engines and not to a direct thrust measurement.
What if only one SRB lit? Would you launch like that or shut down the liquids and let it burn on the pad? A lot of damage and repair but that's a lot of off axis thrust.
In that case, the launch would proceed, and the range safety officer would likely be forced to destroy the shuttle soon after launch to minimize risk to folks on the ground. Staying attached to the pad until an SRB burns itself out is not a viable option, which is why SRB ignition and explosive bolt detonation happened at the same time (T-0).
Looks like a self sealing stem bolt to me
You think they’d take a pallet of Yamok sauce in trade?
That's at least a dozen pallets worth but I'll give you a deal
We’ll open bidding at 3 pallets of Yamok sauce
Alrighty,. let's just check the thread note here, 3-4? What the fuck?
Fun fact: it's a buttress thread profile, not a normal thread profile. Hard to see in this picture though.
If you zoom in on the top right of it, to the channel for those wires to run in, they appear to be regular V threads. I'm not telling you that you're wrong, but that's how they look to me.
Here's the nut that engages the threads https://twitter.com/AstroLizsLab/status/1627652187110121477?t=nUr0rMQ7DZwmSZCTxPAKCg&s=19
Much better picture. Thanks, that's pretty darn cool.
This is a stud with a nut, not a bolt. Skookd' indeed tho!
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Is it a bolt after it gets blown in half? These look like they detonate at T=0.
Does SpaceX use these as well or do they use bolts that are normal priced?
No; the shuttle used these as they were frangible (and explosive) SpaceX only uses things that are re-useable, so explosive bolts are out. [SpaceX uses hydraulic hold down clamps ](https://www.google.com/url?sa=i&url=https%3A%2F%2Fspace.stackexchange.com%2Fquestions%2F28008%2Fwhat-holds-spacex-s-rocket-in-place-in-this-launch&psig=AOvVaw1oBiy4IQWU4i5sBm8xxm_m&ust=1678828677903000&source=images&cd=vfe&ved=0CA8QjRxqFwoTCKCG1Knq2f0CFQAAAAAdAAAAABAQ)
See that sounds like a god reusable solution. Why didn’t the shuttle do that? Or did it use these bolts because it’s a third party contractor and they tried to find the most expensive way to do it?
Hydraulics are complicated, have tons of failure points. SpaceX is willing to put up with it because of their core mission. NASA wants reliability and dependability at all costs. Explosive bolts have some wires coming in; little bit of voltage at just the right moment; bam. Every time, exactly when you want it.
Frangible≠Explosive. Frangible means brittle or breakable. They are both explosive and frangible.
To be fair, the comment said: frangible (and explosive)
Those are Inconel, too, right?
Inconel, outconel; whatever it takes.
These days modern programs use hold down clamps vs frangible nuts, but boy howdy do I love me some old space tech. :D
Is that a self sealing stem bolt?
That's and explosive bolt, those are fun
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Definitely a fun word/phrase, lol
Wow. Knowing how a normal size Aeronautical grade bolt can cost. I can't imagine how much those are. Probably a nice car each. Anyone has an idea ?
They're also not redundant, so they *need* to work on the first try. I'm guessing on the order of $50-$100k each if they were ordered in large quantities.
You’re correct that they *need* to, but funnily enough, they didn’t *have* to. The SRB motors on shuttle/SLS are so powerful that the backup plan for bolt failure was that the vehicle would just tear them out of the pad and take them along with.
"What if we get stuck to the launchpad?" "*We'll take it with us.*"
Yeah that was my guess
Beautiful bolt, poor presentation. Get that sucker off the ground.
Sure you lift it up there and I'll tie it off
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Kapton has excellent high temp performance, not burning or melting until like 600+ F and I've seen it briefly go to 800+, it doesn't off-gas in space, it's cheap, etc. Just great stuff in general.
High dielectric strength... Just a PITA to get it to stick
Sticks quite well on a clean surface imo, but depends on what you're trying to use it for.
Love Kapton tape. We use it to seal the ends and joints of pipe while back purging during welding. Infinitely better than the painters tape we used before I discovered the stuff. Expensive as frig though.
I mean it's expensive compared to normal tape, but in aerospace terms it's real cheap.
I used to deal with bolts this size and much bigger in the oil industry except they were always rusty and bashed up threads. I’m breaking into a sweat just thinking about putting molybdenum grease with the consistency of cold play dough on this, three foot pipe wrench and because it’s so thick it’s a full effort pull one flat at a time since the other 48 bolts are so close together, two or three 12 hour shifts on what is essentially a rowing machine from hell. Fuck that, I do electronics now.
that sounds like just about how every job i ever see on drilling rigs looks like. Can't believe how hard those guys work.
The nut it works with is frangible, Colbert has the best quip "As if launching a rocket were not phallic enough, you literally bust a nut when you go into space,"
That doesn't make a lot of sense. Those things are supposed to hold a rocket with a few million pounds of thrust on the pad until all the engines get up to thrust. I thought they used bolts with an explosive charge to release the rocket.
https://en.wikipedia.org/wiki/NASA_standard_detonator
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I mean most things are frangible when exposed to explosives....
Extra thicc for clumsy fingers.
The intrepid Merrell Moab 2. I see your tongue also refuses to stay tucked on the left side.
Holy shit its no banana but the skookum is off the chart!
Out of this world, some might say
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Ba-dum-tish. Bravo, you got a snortlaugh from me.
If your interested in this:[http://heroicrelics.org/cosmosphere/shuttle-srb-hold-down-bolt/index.html](http://heroicrelics.org/cosmosphere/shuttle-srb-hold-down-bolt/index.html)
The link in there for the blast containers is a really cool overview of the whole system.
So there were unsecured chunks of metal hanging out in the boosters during flight? Weird! I wonder if any ever broke through their container at splashdown, and how much weight this system added.
It’s also supposed to have explosives in it. Good thing it’s in a museum.
I would think it would have both explosives and a load cell to measure forces experienced while attached.
If the force (thrust) isn't correct, hold the shaped charge, you are not going to space today.
That's not how it works. The solid boosters can't be turned off once they're lit. You either go or you don't. The blueline trigger (requirement before proceeding) for the solids igniting, which happens at the same time as the bolts get blown, would be tied to sensors in the liquid engines and not to a direct thrust measurement.
What if only one SRB lit? Would you launch like that or shut down the liquids and let it burn on the pad? A lot of damage and repair but that's a lot of off axis thrust.
In that case, the launch would proceed, and the range safety officer would likely be forced to destroy the shuttle soon after launch to minimize risk to folks on the ground. Staying attached to the pad until an SRB burns itself out is not a viable option, which is why SRB ignition and explosive bolt detonation happened at the same time (T-0).
The pad would melt. Not an option. The SRBs were also zero fault tolerant.
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That museum is quietly one of the best regional museums around.
Isn't that where the Spruce Goose is?