Starbase Tour with Everyday Astronaut — Part 2 30 juillet 2021 Deuxième partie de la visite de Starbase, couvrant le matériel de Starship, les tuiles du bouclier thermique et le choix d'une structure en acier inoxydable.
Deuxième partie de la visite de Starbase, couvrant le matériel de Starship, les tuiles du bouclier thermique et le choix d'une structure en acier inoxydable.
Transcription Tim Dodd
Hi, it's me, Tim Dodd, the everyday astronaut. Welcome to part two of my tour of SpaceX's Starbase factory with the ultimate tour guide, Elon Musk. If you haven't watched part one, you obviously need to watch that because there's just gobs of information. And in this part we're actually going to go inside the three main assembly tents, which is incredible. And just like last time, we have a map that will occasionally pop up, courtesy of ring watchers on Twitter that'll help you understand where exactly we are in the factory. We also have the YouTube play bar broken up into certain sect sections. We have links to those sections below too. And we have an article up on our website that has some key points and takeaways of this conversation. The link in the description is below for that@everydayastronaut.com. all right, let's go check out some Raptor engines. So by the way, I think there's a good chance that itar and comms might not want all.
Elon Musk
Yeah, just like, you know, it just can't be any. Any more than people are already getting from telephoto lenses.
Tim Dodd
That's which is pretty much.
Elon Musk
And frankly, if some fool wants to copy this design, go for. I mean, Raptor 2 is a giant improvement over this.
Tim Dodd
So what's like the big simplifications you're hoping to have?
Elon Musk
Well, maybe I shouldn't tell you all the secrets. We have, like funny things on the Pikachu over there.
Elon Musk
So that probably.
Tim Dodd
I assume that means it's flown. Is that a flown one?
Elon Musk
I don't know if this one's been flown.
Tim Dodd
This really does look like that thing with all the NK33s, you know, the videos.
Elon Musk
Yeah, exactly. Like the engines discovered engines that came back from the coal.
Tim Dodd
Yes, it seriously literally looks like that. This is insane. And then, man, that rat rack is big. Jeez.
Elon Musk
I want to tell you all the secrets, but just like you will be able to see the difference very clearly. Okay. And I guess since the engines are. It's hard to have people not see them. Yeah, they will. You. Well, Raptor 2 is visibly cleaner than Raptor 1. Like, it's this, this sort of maze of plumbing and wiring doesn't exist on Raptor 2.
Tim Dodd
Well, it's already slimmed down a ton from like, you know, the.
Elon Musk
It used to look like a freaking Christmas tree. Yeah, like you couldn't even see the engine for all the stuff that was ready.
Tim Dodd
No, you really couldn't. And now it's like especially around the turbines and stuff and the pre burners. It's. I mean, that used to be a whole. There's sensors every. Every 2 millimeters.
Tim Dodd
So RapVac or RaptorVac has its own channel on the extension. It looks like.
Elon Musk
Yeah, that's a steel tube wall. Braised steel tube wall.
Tim Dodd
That looks great. And it has a different profile too. That actually looks like the initial exit. Is there a different throat in it and everything or is it.
Elon Musk
Throat's the same, Throat's the same. It's just the part after the throat that's the diverging section has a different angle. It's basically spalling a rock contour for a higher expansion ratio. Yeah, yeah.
Tim Dodd
What is expansion ratio again? Is it like 150 or.
Elon Musk
Man. I think we're. So this is actually there's. I think we're around 80ish.
Elon Musk
But we want to get to. We want to do a little bit better. Maybe 90, so.
Tim Dodd
Because you're already getting like 380 ISP out of that thing, aren't you? I mean, sorry.
Elon Musk
Yeah,383.80 is the aspirational number. Okay. But we should be. I think we think we'll get like 370. 378.
Tim Dodd
Okay, how are those coming along? It looks like obviously you've got a third one here. You've obviously made at least three.
Tim Dodd
And obviously S20 is going to have three. Yes, yes.
Elon Musk
But the. For Raptor, all engines will have the same pumps and thrust chamber assembly. So it's really just. They'll be in one sort of one variant that has a big nozzle and one variant that doesn't have thrust vector control actuators. Okay. Okay, so that's.
Tim Dodd
And that's going to be the difference between the R boost and the.
Elon Musk
Yeah, I mean, it's basically the same engine minus pvc.
Tim Dodd
Gotcha. So the outer shells that you're working on for The GSE are 1212 meters.
Elon Musk
There's a Raptor without the stuff. Looks practically naked.
Tim Dodd
You're like, actually that's secretly version two. It's super simple.
Elon Musk
No, version two will look a bit like that actually.
Elon Musk
It's very tight.
Tim Dodd
Really? I mean, again, kind of when you look at some of those Soviet engines, they were also like incredibly simple looking. I'm guessing they just obviously didn't have them wired to the gills with. With electronics though, either.
Elon Musk
You know, they simply did. Back in those days they did not have good electronics.
Elon Musk
So there's nothing to.
Tim Dodd
There's nothing to wire.
Tim Dodd
Is how much like I feel like you. You iterate this quite a bit and remind people that it's failure kind of is an option. Why do you think people are so afraid to fail? And why do you embrace it? Or how do you teach that culture even that it's okay when you're not even trying to like, you know, SN8 is a perfect example. You weren't trying to like do a mission. You're just trying to get data out of the thing. Yeah.
Elon Musk
We have just a fundamentally different optimization for starship versus say like the polar extreme would be Dragon. Like Dragon. That could be no failures ever. Everything's got to be tested to, you know, six ways to Sunday. There has to be tons of margin. There can never be a failure ever for any reason whatsoever. Yeah. So they cannot be. We can't be. So that's like extreme conservatism then. Falcon is a little less conservative. It is possible for us to have, say, a failure of the booster on landing. That's not the end of the world. And then for starships is like the polar opposite of Dragon. We're iterating rapidly in order to create the first ever fully reusable rocket. Orbital rocket. And fully and rapidly reusable. Reusable in a way that is like an aircraft. So rapidly reusable rocket.
Elon Musk
Yeah. That's the fundamental holy grail for making life multi planetary.
Tim Dodd
Where do you think the space shuttle failed in being in any. Definitely. Rapidly would be a word you got to scratch off the list.
Elon Musk
And refurbishable might be a better word.
Tim Dodd
But where do you think it failed and where do you think. What lessons have you learned that you know you're not going to be making on starship?
Elon Musk
Space shuttle had almost no room for iteration because there were people on board. So you couldn't be blown off shuttles. Yeah. So that's a big problem. Yeah.
Tim Dodd
Well, they did very, very little. I mean.
Elon Musk
Yeah, very little. In fact, lack of iteration was the problem because a lot of the issues they were aware of, but people were too afraid to make change.
Tim Dodd
Because the design froze.
Elon Musk
Yeah. Because it's like. Yeah. I mean, there was risk, reward, asymmetry. So big punishment for if you make a change if something goes wrong. Big punishment if you make a change and it goes right. Small reward. So the issues with the O ring and then with the insulation coming off and hitting the wing.
Elon Musk
Where they'd seen this before.
Elon Musk
They were known that there are known issues. Yeah. So which, but it, because it had worked before, they're like, well, it worked before. Russian roulette works before.
Elon Musk
So look, I've pulled the trigger so many times. Must be no bulletin, it must be no problem. Yeah. So anyway, it's hard to iterate though, when people aren't on every mission. So you can't just be blowing stuff up because you're going to kill people. Starship does not have anyone on board, so we can blow things up. That's really helpful.
Tim Dodd
Do you have any considerations yet on any kind of launch escape or are you just hoping that by the time you put people on it, you've flown it say 100 to 200 times and you're familiar with all the failure modes, you've mitigated it to a high degree of confidence. Or what's your.
Elon Musk
Yeah, launch escape, I think is. Yeah, you basically just need to fly a lot and have a lot of redundancy. So if you lose an engine on the booster, it doesn't matter. Basically if you lose multiple engines, it shouldn't matter and you should be able to lose an engine on the ship. Everything's okay. So. Because launch escape is basically just protecting you for the ascent phase. And actually most launch escape systems only protect you for a small part of the ascent phase. Because the typical launch escape system is a solid rocket motor on the tip of the capsule, which then has to be
Elon Musk
It has to be jettisoned on every mission. So if it's not jettisoned, the crew dies.
Tim Dodd
That's a failure mode right there.
Elon Musk
That's a failure mode. So you have a state change post liftoff, which is bad then because the damn thing's so heavy they also can't carry it all the way to orbit. So they'll typically jettison the escape system shortly after a second stage ignition or final stage ignition so that you don't have escape all the way to orbit. Even now, at least with Dragon, we have escape all the way to orbit. So that's like, I think safety improvement. But, but then you, you know, there's no escape system coming back to Earth, like that doesn't exist.
Elon Musk
And then there's, you can't have an escape system on the moon or on Mars.
Elon Musk
Yeah, yeah. So like you can't have something pop off and then have chutes drop. There's no atmosphere. And then Mars has a very low density atmosphere. So yeah, it'll just like hit the ground supersonic, you know.
Elon Musk
So they're not gonna save you so the ship has to be safe enough for people without an escape system, because otherwise you can't go to the moon, can't go to Mars.
Elon Musk
So kind of pointless to do it on Earth. Well, it just fly it a lot.
Tim Dodd
Right. And that, I mean, I never really thought about that. That, you know, you're gonna be, you know, you're gonna be flying so much without fear of retribution, of failure, that unlike the shuttle like you mentioned, I just never really considered that you. So let's see what. What is. Oh, that's all. Those are the vacuum mounts, aren't they?
Tim Dodd
Wow, that's cool.
Elon Musk
Yeah, I mean, this is our stuff, like very much version one. So, yeah, it could be. It'll be a lot better with the next iteration.
Tim Dodd
Well, a lot of people ask me, you know, like, hey, I want to start a YouTube video. Where do I start? And I'll be like, start. You just have to start. And I kind of feel like this is a similar philosophy. It's like you're not going to know what's wrong or how to make it better until you do it at least once anyway, you know, and you just simply have to start. You have to force yourself to start.
Tim Dodd
And then. Yeah, that's. That you improve from there.
Tim Dodd
Man, are you pretty used to the heat. I feel like it's. It's pretty hot out here.
Elon Musk
It is hot. I mean, this is the worst. This is like summer, you know, so.
Elon Musk
That's just like the worst of it.
Elon Musk
It's not that bad if you think like, just pretend you're in Hawaii. Right. There you go. So speaking of shuttle, I mean, I think it's a cool view.
Tim Dodd
Oh, it's a really cool view. And thermal protection. It seems like you guys have made some. I mean, it looks like S20 is going to be pretty well decked out in the stuff. How are you feeling about the thermal protection system? You feel like that's a pretty good solution?
Tim Dodd
They've been holding up pretty good, at least on the. On the low altitude stuff. As far as the mounting points and stuff like that.
Elon Musk
It hasn't full. I mean, it's still there. I mean, you can see the videos.
Elon Musk
It takes off with the tiles and it lands with the tiles. Yep. And we have, I think, a good attach mechanism, which seems like a good attach mechanism because it allows. It's just mechanically attached with some play in the tile. So the tile can move a little bit. Like it's quite a tricky thing with the Tiles. Because the tiles are essentially ceramic and they're attached to a metal substructure that is changing in temperature dramatically. So it'll be room temperature right now. Then it'll drop to cryo temperature. When it's loaded with cryogenic propellants. Then it will be heated up with hot ullage gas. So now it'll be way above room temperature. Then it'll cool down. Then the tiles will themselves will get hot on re entry. And they also have some expansion. Yeah. So there's a lot of expanding and contracting going on all over the place. So I think one of the big questions is are these tiles, are we going to have a crack or a gap in the tiles? Like if they bang into each other the ceramics like a coffee cup. The ceramic. So you bang two coffee cups together. It's usually bad, not good. Yeah. So if we, if the tiles bang each other and crack, this could be. This could result in a failure on entry. So I think there's like a huge question of like when we get the ship to orbit, how is it able to make it back through Earth's atmosphere? Because it's coming like a meteor. It's like blazing hot meteor. And will the heat shield stand up to it or if there's any crack in the armor, it's gonna. It's host.
Elon Musk
So hopefully we at least find out where the crack in the armor is. That would be great.
Tim Dodd
And then if you have to, you can make some thicker or smaller iterate to that degree of where you find those failures again.
Tim Dodd
How will you know? Like what if something just goes. What if you know, the first orbital attempt just goes totally, you know, doesn't even make it in for reentry. It's just a million pieces at the bottom of the ocean. How will you know where it failed?
Elon Musk
I mean we have temperature sensors. You probably need like some thermal images inside the tanks. So just like IR camera so you
Tim Dodd
can see if certain specs is getting real hot.
Elon Musk
Yeah. IR cameras on the inside will show you what the backside temperature is.
Tim Dodd
Yeah, yeah. Let you know if a leak something
Elon Musk
gonna pop if the backside temperature like it was. Frankly I'm not sure. I take it back. If you just have a camera. Camera.
Tim Dodd
Yeah. You'll know.
Elon Musk
Visual. Yeah, you'll see it's something glowing white hot. Okay, that's bad. Yeah, that's the bad part right there. So you don't even need a thermal engine, frankly. The steel will glow white hot before it melts.
Elon Musk
So you'll know you'll know. It's so subtle.
Tim Dodd
And the very first orbital test, again, it kind of seems like. Are you guys. There's been a lot of debate of like, is it going to orbit and deorbiting or is it just orbital velocity with a low perigee that's inside the atmosphere and that's how it is deorbit, like, will it.
Elon Musk
It's getting to orbital velocity, but with a. With a. But it's. It's not circularizing. It's perigee.
Elon Musk
So it basically goes like 3/4 of the way around the Earth. But because we didn't raise the perigee, the atmospheric drag will pull it in.
Tim Dodd
Yep. And the velocity will probably be greater re. Entry velocity will be greater that way. Or similar.
Elon Musk
Similar. Yeah. It's not. It's not a huge difference, but it's. It basically it like, it could easily, like if you just pop like the attitude control thrusters or like the ultra gas ullage gas alone could put it into orbit. So like, raising perigee slightly is easy? Yeah, yeah. It's like remarkably easy. So we just want to raise it like a little bit.
Tim Dodd
Are you hoping to actually recover the first one or like, try to even land or any. I mean, is it going to.
Elon Musk
First one is for the first orbital launch. Our goal is to make it to orbit without blowing up. That's our goal. And frankly, if we even get the. If the booster even does its job and something goes wrong with the ship, I still count that as good progress. Yeah, like, basically. Actually, to be totally frank, if it takes off without blowing up, blowing up the stand of stage zero, which is much harder to replace than the booster, that would be a victory. Please do not blow up on the stand. That's my one concern.
Tim Dodd
But you keep calling, you, calling the stand Stage zero, the launch system. Really? Yeah, the ground, gse, the tower and all that stuff.
Elon Musk
Zero. Yeah. Okay.
Tim Dodd
Yeah, that's. I. I just get. I got so spoiled now with again, Soviet nomenclature. It's like there's zero for like the boosters of Soyuz.
Tim Dodd
And then what I would call the.
Tim Dodd
No, sorry. Opposite. The boosters are one, core is two. But what, like the next upper stage or what I would consider stage two is stage three. So it's really confusing. And I kept being like, oh, yeah, third, you know, second stage. And they're like, no, no, that's third stage, you know.
Elon Musk
So stage zero, the launch system. Yeah, the launch mount, the flame diverter, sort of. Yeah, sort of the big tower, the Propellant farm and all that. Basically, you know, all the lines and everything. That's stage zero. And it's very hard. Yeah, it's harder for us to make a stage zero than to make a booster or a ship. So hopefully it doesn't blow. Yes, that would be great. And then the best case outcome for the first flight would be that
Elon Musk
booster does its job and also is able to relight the engines and it's going to splash down in the Gulf.
Tim Dodd
Only like 20 miles out or something. Something. Right, yeah.
Elon Musk
Not far relative. And then the, the ship or upper stage is going to come in just off the coast of Hawaii near a military base there. And so we'll, you know, splash down in the Pacific.
Tim Dodd
Yep, yep. So. So again, to reiterate on the first launch, you won't. The booster, you're going to just use the gas venting to orient it for reentry, is it? Well, it won't even do a, you will do a boost back burn though on the first one too, right?
Elon Musk
Let's just say it's an evolving situation. Yeah. In order to be 20 miles away, we definitely would have to do some kind of boost back, otherwise it's gonna be way further.
Elon Musk
So yeah, I mean probably it's boost back and then a propulsive and then basically you want to simulate the landing but not have it be too close to land. So it doesn't take out stage zero.
Tim Dodd
Right, Yep. Yeah.
Elon Musk
So we want to see like basically can we position the booster precisely such that if it had landed next to the tower or if it had come to a halt next to the tower, could the arms have grabbed it?
Tim Dodd
Yeah, Mechazilla.
Tim Dodd
Mechazilla. Mecha Mechazilla.
Elon Musk
Okay. Yeah. Like a giant Mechazilla. Yeah.
Tim Dodd
And how, what's, what's the plan? Does it just come in and it sits then on the, on the grid fins and, or that little arrestor thing,
Elon Musk
those, those little, the little tiny arms.
Tim Dodd
That tiny little T. Rex arm is going to hold the.
Elon Musk
Yes, there's two of them. But those, those things can take a
Tim Dodd
lot of load and then it's just literally like a flat, like a flat arm kind of like this, that.
Elon Musk
I mean this is one of those things. Like it's hard to keep a secret when it's right there. People can just take zoomed up like drive past it and take a high res photo close up. So it's not exactly going to be top secret.
Elon Musk
This is the first real big Rocket development that's been so close to public road that people are literally driving to the beach right past the launch site. So it's hard to keep a secret around here.
Tim Dodd
That brings up, I always keep wondering, like, you know, we're seeing this insane pace. We're seeing all these crazy things happen. How much of that like is normal, at least as far as SpaceX goes, or how much is that is just because we're actually seeing it. Like for instance, when you're developing Merlin and Falcon 9, were you blowing stuff up this much, doing things so crazy fast paced or is this like also fast paced? But now we're also seeing it all, so it's hard to compare.
Elon Musk
Well, I mean this is definitely a case where we are washing our laundry in public.
Elon Musk
And there are, there's always dirty laundry in any program. It's really a question of whether it is seen or not. Not. Is there daily laundry?
Elon Musk
Yeah, every program has got daily laundry, but in this case it's in public. But this is also a case where we're intentionally iterating the design rapidly. And basically ships and boosters will either be amazing lawn ornaments which then have to be stored and they look awesome, but we don't want 12 of them. It's going to look bizarre and where will we put them? So since we're making rapid iterations with each, almost with basically every single ship and booster has had significant iterations. But you either want it to blow up or the early ones you want them to blow up or you're going to have to find a place to store them. So we actually want to push the envelope. And frankly if you don't push the envelope, you cannot achieve the goal of a fully and rapidly reusable rocket. It's not possible. You have to go close to the edge on margins. And there's a recursive factor to mass. So if you add say an extra ton of heat shielding now you also need more propellants to get it to orbit and you need more propellants to deorbit it and you need more propellants to land it. Yes. And the structure now has more load. So because it's carrying that extra ton of heat shield.
Elon Musk
So this applies to any given ton. There's a recursive value. So in order to achieve the same payload, you have to. Each ton is like basically almost like adding 2 tons when it's fully considered.
Elon Musk
So I think we calculated it to be like a 1.8 factor, but I think it's probably we're forgetting something that's so close to it too. So every one ton of mass forgets an extra ton. Yeah.
Tim Dodd
So what's for instance, like what's S20s dry mass kind of looking like. What are you at right now? Are you like one 120 tons or are you.
Elon Musk
I actually don't know the exact mass of 20. We'll know it when we weigh it.
Elon Musk
There's a lot of parts that have not been weighed. Yeah, so. So like what does it actually, I mean, I hope it's not too insane. Ideally its dry mass is hopefully not much more than 100 tons.
Elon Musk
So. Yes, but then you say like dry. Do you mean not counting the air inside it,
Tim Dodd
by the way? The air.
Elon Musk
Actually air mass is non trivial.
Elon Musk
This is a giant volume. And then do you mean dry? Do you mean with propellant residuals and ullage gas which is at several atmospheres? Which mass are you referring to? Like sometimes in these things they'll play games with like the. Where you say thrust away of a rocket engine. So thrust away the rocket engine with or without residuals. That's a big change.
Tim Dodd
Or with or without gimbal is something else that I've heard people kind of debate.
Elon Musk
Yeah. Yeah. Well then I'm pretty sure by any standard the. I think it's probably the best thruster weight of any engine because it's like just so far we really pushed the GD cycle engine to the. It's like A plus for GG cycle architecture. But GG cycle architecture is not an A plus architecture.
Elon Musk
Full flow stage combustion, A plus architecture. But with a new architecture, we won't get an A within that. Like it's like in gymnastics, you know, you like say how hard is your program and then what grade you get in the program. Yeah, that's kind of how the, you know, things work here.
Tim Dodd
So what would you say version two is going to kind of come in at if you were to rate on.
Elon Musk
I don't know, I'd say it's like B plus. Okay. Something like that.
Tim Dodd
So good enough for now. But of course, yeah.
Elon Musk
Raptor 3, Raptor 4, Raptor 5. You know by Raptor 5 it'll be an A plus.
Tim Dodd
Should we walk through here and check out what's going on in here? Is this. This is just a nose cone being assembled? It's not, it's not that it's showing.
Elon Musk
This is. This is a new and improved nose cone.
Tim Dodd
Oh yeah. It's just straight. There's no cross section.
Elon Musk
So this is if you look at that nose cone over there, that's made from stamp sections. Yeah. So you can see that's like three rows of stamped sections. Yep. This is, this is, this, this will be made of two rows of stretch formed.
Elon Musk
So and you can see it's like it's just way smoother.
Elon Musk
This is stretched over a man like a big mandrel. So just take it, just take a big sheet of steel and you just stretch it over this giant tool.
Tim Dodd
Right, right, right.
Elon Musk
And then you can, you can have like things that are way bigger. Like you can't put this in a stamping press.
Elon Musk
This is way too big. That's like basically about as long as you can fit in a stamping press. You could not fit something that's giant. Or you could technically make some totally special case stamping machine that doesn't exist.
Elon Musk
But you only need one essentially a single sided. It doesn't have like indentations or anything so you couldn't make a car body side this way. But you can make something with this level of symmetry that is basically you can do a one sided die. So you can just stretch form it over a big mandrel.
Tim Dodd
And this isn't the cargo. It's not show. It's just not complete yet. But it had that opening on the one side that's not. Because you're working on the door, the jaws yet, right?
Elon Musk
Yeah, I actually stopped work on the, on the door, the fairing door.
Elon Musk
Yeah, we're going to focus on getting to of it. Yep. We don't need a door.
Elon Musk
So it's like we just need, we need to be super focused on getting to of it and super focused on getting the ship back. Then we can worry about doors. Okay. It's just unnecessary complexity. So like is the door necessary to solve the problem? No. Will we use this like the first 10 or more that that get back from orbit? We won't, we probably won't fly them again. Right. Or maybe once or twice. But then they're going to be in storage like for Falcon 9 and even like the block 5, so called block 5, which is more like version 7 really. But we don't even want to use the early block 5s, so like even those are a pain in the ass and we prefer to retire them. So like when we have like a mission that requires an expendable booster, we'll put an early block 5. Because the early block 5s are not as good as the later block 5s. And they're more of a pain in the ass to get ready for flight.
Elon Musk
So the reality is the early ones are gonna be amazing lone ornaments.
Elon Musk
I mean, as good as lone ornament gets, but they will not be
Elon Musk
as good as the ones that follow. So then why keep them flying?
Tim Dodd
They're not even gonna be doing any, you know, they're not gonna be putting any payload up. You know, they're not. You don't even need to worry about it.
Elon Musk
They're just gonna retire the early ones anyway, so.
Elon Musk
Why have a door on a thing that. Then we're gonna fly satellites anyway. Yeah.
Tim Dodd
How. How is the. The butt to butt refueling going? Is that. Because that's got to be a pretty early consideration. You're probably gonna want to start testing that.
Elon Musk
No, that's. No, we got. No, we're gonna get to orbit and back first. Okay. We don't need. We don't need orbital refilling. Unless you want to go to the moon, you need orbital refilling. Going to Mars, you need orbital refilling. Delivering satellites to Earth orbits, you do not need orbital refilling.
Elon Musk
So let's punt that to later.
Elon Musk
I'm not sure it'll be the butt spot. It might be something different, like the. We're actually. We switched the propellant full drain lines to V side to come in from
Tim Dodd
the side, not up through the booster
Elon Musk
anymore because I was adding a bunch of stuff to the booster, and then we're flying it every time. So it's better if you can move masts to the ground side. It's better to move mast to the ground side.
Elon Musk
That's why we took the legs off the booster and just have the tower catch it.
Tim Dodd
Are you thinking about doing a tower catch it?
Elon Musk
Which sounds mad. I mean, yeah, I know it sounds insane, but when I, like, suggested that, people thought I lost my mind, which I'm like, maybe I have, but I think it might take a few kicks if they can, but we'll get it right. And then. And the work that you have to do to pick up the booster and put it on the launch stand, this gigantic skyscraper thing, in high wind, you know, like, windy situations. It's very windy around here.
Elon Musk
So you pick up this booster, you got to put it onto its stand with precision. Then you got to pick a ship up and put it up on top of that. So that means you've got to have a secondary arm to steady the booster so it's not moving around all over the place. And then while the sort of Mechazole arms pick up the ship and put it on the booster. Okay.
Tim Dodd
So the Mechazilla arms are the ones that are going to be picking up the ship, not the crane.
Elon Musk
Okay. So. It's very important to appreciate that everything you see here is a work in progress. What is said last week may be untrue next week.
Tim Dodd
We've seen that a few times.
Elon Musk
Yes. It could be that we were actually just literally mistaken, a miscommunication,
Elon Musk
of a number of things. We just found a better. Had a better idea in the case of, like, for the first stacking, we're going to do that with a crane. Yeah, we will. So, yeah, Marvin the Martian right there. I love that. So the first one we're going to stack with the crane because otherwise we'd have to wait for the, the, all the mechanisms to work. So we were like, we're like assembling the arms and, you know, basically putting Mechazole together. But in the meantime, we could be launching. So let's not wait for the tower to be completed. We've got like the second biggest crane on Earth. We don't necessarily want to have the second biggest crane on Earth just sitting there forever, but it can be there for the first stacking. And then from the first stacking, then we can figure out. Just like, do we have the hold downs? The hold downs work, you know, like all the launch mounts, I should say. Yeah. So it's really quite a complicated launch mount. It's got, it's got like basically 20 mount points.
Elon Musk
And you got to line those things up and then put the booster on it and have, you know. Does it fit okay? It doesn't. It won't fit right now. We gotta adjust it.
Elon Musk
Okay. That, that, that launch ring is 370 tons. So. And it's gonna tweak. Like you move it from one place to another. Tweaks.
Elon Musk
You know, it doesn't stay exactly the same, so we're gonna have to like jiggle it around a little bit, put in some shims and stuff and put the booster. So we want to do that soon. We should be done with this booster, I don't know, next week. Yep. So. Wow. So then we want to mount the booster next week.
Tim Dodd
It's gonna be, that's gonna be insane to see.
Elon Musk
Yeah, we're gonna try to put the ring on the stand, the launch ring on the stand tomorrow.
Elon Musk
But we may not succeed. We'll see. So probably the Second flight will use. I mean, it's very likely the second flight, we'll use the tower.
Tim Dodd
Okay. Second flight, we'll use. Oh, so the first flight might still use the suborbital pad.
Elon Musk
No, it's going to use the. It has to use the orbital pad. We can't.
Elon Musk
The sub orbital pad cannot take the full weight of the stack. It's going to get crushed. And it doesn't have enough height, so the rocket would blast itself in the face. It's too low and too weak.
Elon Musk
Okay, so we got to launch it from the super beefy stand.
Elon Musk
But we don't want to wait until everything's ready with the tower just to stack.
Tim Dodd
Okay, so how will you secure it then when it's stacked? Like, just drop the starship on top of the crane holders until it's launch time. And then
Elon Musk
we do need the, The QD arm to work.
Tim Dodd
Oh, right. So that can be a stability thing.
Elon Musk
Yeah, exactly. It holds it, it stabilizes it and transfers propellant. If we don't have that, we can't load prop in the second on the ship.
Tim Dodd
Okay, so that has to be complete. Yes, but not necessarily the arms and everything else going on at that point.
Tim Dodd
so at this point. At this point, I mean, we're.
Elon Musk
Like I said, it's. There's a lot of moving pieces here. So some of this could be ready in time. It's possible that the tower could be ready in time, in which case we'll use the tower, but if the tower's already in time, we'll use the crane. Okay. Yeah.
Tim Dodd
So at this point in development, what things are like, what things are you being kept up by at night? Like, what's the thing like, oh, we just need to, you know, do this or this better or we really. I can't sleep because I'm not feeling. We're not. We haven't figured this out yet.
Tim Dodd
Yeah. So what, like what things are just totally keeping you up at night at this point? What's the thing. What's the thing that you feel like you still have to solve at this point?
Elon Musk
I mean, it's a long list. So
Tim Dodd
what's at the top of that right now, for you, at least personally?
Elon Musk
Well, this is really all just measured as in terms of time. Like, what is the time risk associated with something. The one thing you cannot replace is time. And I do have a habit of being optimistic with schedule. I mean, if I wasn't optimistic, I wouldn't be doing, you know, the crazy Things that I'm doing.
Elon Musk
So I must have like, I don't know, just pathologically optimistic, I suppose.
Elon Musk
That's. Yeah. It looks like dragon scales.
Tim Dodd
It is incredible.
Elon Musk
That looks cool.
Tim Dodd
It's actually like coming together a lot.
Elon Musk
It totally looks like dragon scales.
Tim Dodd
And it's. It's so much tidier and cleaner looking than I thought.
Elon Musk
Yeah. I mean there's a few broken tiles, but overall it looks cool.
Tim Dodd
That's incredible.
Tim Dodd
So I guess the joints is one of those things that the community has always wanted to know about. You know, I guess the good thing is the, the flaps will for mostly take most of the wind from this area that you see. So I guess you don't really have to cool the inside of the like the flap joint itself because it's kind of already.
Elon Musk
No, actually, unfortunately we do. I think we have significant. I think again, take a lot of what I'm saying with a grain of salt because I often am wrong. So sometimes I'll say something that's wrong, but I'll. You know,
Elon Musk
I think we have a design error with, With the. The non moving portion of the forward flats. Okay. Because the reason we have the flaps and the static arrow, basically the unmoving portion of the plats are there to do two things to balance the rebalance the ship. So it doesn't come in engines first because that's otherwise the. Where the center of mass is quite low and it will come in engines first and burn up the engines. Yep. So first you have to rebalance it so that in a hypersonic regime you're doing like roughly sort of like 60 to 70 degree angle of attack because you have a. You're applying a trajectory that minimizes peak heat. But you don't care about total heat load. You just care about minimizing your peak
Tim Dodd
heat because you have a, A good insulator here. Not, you know, you're not blading.
Elon Musk
Yes, exactly. So if you have an ablative heat shield like Dragon, technically that Dragon is like fairly reusable actually because it's sort of like a brake pad. You could fly it many times.
Elon Musk
Because it's got so much margin. Yeah. But apica is, is literally means phenolic impregnated carbon ablator.
Elon Musk
So that's the Dragon heat shield. So Dragon's like, hey, let's have a. Give me a high peak heating, but don't make my total heat load high. Because what Dragon is trying to optimize for is what is the heat pulse? When it's under parachutes and it's been. So the heat pulse moves through the tile and then reaches the back to where it's bonded to the carbon fiber composite sandwich structure. And if the heat pulse is too, if the heat is too high, it will melt the glue and the heat shield tiles will start falling off and then they will potentially, you know, damage the parachute.
Elon Musk
Yeah, you start having like these things like flying off potentially because they're low density so they're pretty and, and like it's like. Admittedly it's kind of a corner case, but that's it. That's like the, that's the like the Dragon heat shield tiles are way over thick because not because of how much of the heat shield will be bladed, but because of the heat pulse that will reach the back of the heat shield that might melt the glue while it's under parachutes.
Tim Dodd
Wow. Yeah. Interesting constraint at the end of it
Elon Musk
all, you know, so if you just have a lot of heat, suddenly that's actually better for Dragon. Like high peak, low, total heating.
Tim Dodd
Yep, yep. And so it's re. Entry point profile is totally different too. You can come in steeper as opposed to coming.
Elon Musk
Dragon wants to come in like just real steep. And it's like the lift over drag ratio is low for Dragon. I mean a lot of people look at it and say it doesn't have any lift, but it does. If you have a gumdrop shaped thing and you have offset center of mass, then you can control it because it has a small lift vector. Because the gumdrop is like tilting into the wind slightly, it's quite low. And actually LOD is a function of Mach number people. Most people will quote an L if you need L over D number. But like okay, what Mach was that?
Elon Musk
And it's usually like some sort of reference Mach number. But like your LOD is complete trash at like Mach 20. It's garbage, nothing basically. So it's like LOD at what Mach number? Anyway, so it's got a very low lvd, but it does have a lift vector. And then because it is symmetric or more or less symmetric with little thrusters, you can rotate the capsule as it's coming in and change that lift vector. And then so then you and you have a landing ellipsoid because your accuracy longitudinally is less than your accuracy left or right because you're changing the motion vector. You say, well, how do you change the point where you land if you can turn left or right? But how do you change is you do a series of S turns. So you S turn and depending upon how much you bank during the S turns, that affects your longitudinal point. And then your lateral point is pretty easy to tune because you just, you have a lift vector going left and right.
Tim Dodd
It's not so much. People might think like, oh, you're going up and down. That really doesn't work in the grand scheme of orbital velocities and everything. It's really about just your actual velocity and where you end up arresting your velocity is where you're going to drop it to the ground. Pretty much. More or less.
Elon Musk
I think it's just very important for people to appreciate that there's a very gigantic difference between orbit and space.
Elon Musk
It is, it is actually relatively easy to get to space, but it is very hard to get to orbit.
Elon Musk
And then if you say you want to go to orbit and come back, this is easily 100 times hotter than getting to space. Yeah, maybe about. It's so much harder that hardly anyone's even like, you know, only a few countries have been able to do it.
Elon Musk
So, you know, whereas Bert Ratan went to space twice, like 12 years ago, I don't know, 15 years ago, 2005. Yeah, yeah, it was like 15 years ago.
Elon Musk
He went to the border of space twice and didn't even need, didn't even scorch the paint.
Elon Musk
So that's like, it's really not very hot if you don't even burn the paint.
Tim Dodd
Right. That's true. Yeah, that's true.
Elon Musk
Whereas this needs like really intense heat shielding or it's gonna get, you know, blow up, basically.
Tim Dodd
Yeah, yeah. It's crazy to see now, honestly. So is there some considerations to make the fix? Can we go out this way or is it.
Elon Musk
Yeah, I mean, just don't let anything drop in your head.
Tim Dodd
All right, deal. So there's another barrel section of S20.
Elon Musk
I mean, it looks a little garage shop, to be frank, but it's, it's like weirdly like super advanced technology with garage shop.
Tim Dodd
Well, it is very unique of you guys to basically build the rockets first and then start building a factory around
Elon Musk
it, you know, because the production system is the actual hard thing.
Elon Musk
The rocket design is relatively easy compared to the factory. And these tiles are actually made in Florida at our. At a SpaceX factory, which is called a bakery in Florida. It's next to a run Johns, literally.
Tim Dodd
What's the future for Florida with Starship? Are you going to get it flying 100%. Get it all figured out, basically. At least get like orbital version ready and then start setting up shop in Florida and do like.
Elon Musk
Yeah, I think we want to kind of iron out the major issues here. And then we'll certainly be launching Starship from the Cape. We might do more at the Cape, but we'll certainly be launching Starship from the Cape. And like I said, we make the heat shield tiles, which is actually quite a big factory to make these heat shield tiles. Not a small factory.
Tim Dodd
So next to Ron John's. I didn't.
Elon Musk
Well, technically it's next to Ron John's distribution warehouse.
Elon Musk
Literally, I was like, is that a surf shop? Yeah. Or maybe it's like a factory, I don't know. But it's got a Ron John's logo. But the factory, the SpaceX heat shield tile factory, is quite big. It's not tiny because there's a lot of. You need to make a lot of these tiles.
Tim Dodd
And for the most part, I'm surprised at the taper. It looks like they're all still uniform tiles, which obviously is a huge improvement compared to the shuttle. Instead of having 24,000 unique tiles, as
Elon Musk
you can see, we're figuring it out.
Tim Dodd
I'm surprised though. Even as the. As the area tapers, it's not, I
Elon Musk
would say, Mara's head of heat shield engineering. It's like, I'm gonna text him like, yo, man, what's going on?
Tim Dodd
It doesn't seem like there's a ton of unique. They mostly look uniform, which obviously will help with.
Elon Musk
Yeah, they're not all uniform, but a
Tim Dodd
lot more than the shuttle. What's your expected? What are you hoping to get for reuse out of these things?
Elon Musk
Oh, I mean, no meaningful limit. As many as you want.
Tim Dodd
There we go. We got right back into cameraception for you there for a second. Camera inside a camera.
Elon Musk
Yeah, there are different shaped tiles. You can see some of them at the border. There are square instead of hexagons. And then because the static arrow is. It's still seeing actually a lot of heat. The piece of plasma is hitting this. It's hitting the surface and then it's moving around. It's got to somehow get past it. So the get superheated plasma hitting in that thing, then riding up the side of the vehicle, hitting that static arrow. So you actually have a heat concentration there. And then you've got a hinge that you have to protect the hinge. This is if you said like, okay, what's highest probability of failure on re entry? It's probably the hinge of the flaps. So the rear hinge and the forward hinge of the flaps. Because you have to have a rotating thing, but you can't just make everything out of tiles. So you have to have a seal. So you have to seal against. Against the tiles. The tiles are ceramic, like a seal against dinner plates that are super hot. So you can't use rubber.
Elon Musk
So it's going to be a metal seal and with a torturous path.
Tim Dodd
Have you thought about. Back in the day, you talked about transpirational cooling.
Elon Musk
Yes. So that's one of the things you could throw at it is transpiration cooler joint.
Tim Dodd
That would be. So I just want to see it bleeding. Methane, honestly. And just.
Elon Musk
It'll definitely help.
Tim Dodd
Yeah. Because you can kind of purge that joint with a higher, higher pressure gas. You know, as long as it's higher than the ambient air stream or the plasma stream, it will create a thermal barrier.
Elon Musk
It's definitely one of the things if you really want to nail the heating on the hinge is bleed fuel gas into the thing. Because actually, even the burning methane is like, with air, because air is only like 21% oxygen. Air is like, if you ask me, what are you breathing? They think they're breathing oxygen. You're breathing nitrogen with some oxygen, a little argon, all gone. And trace gases. So. But essentially methane with air, which is mostly not oxygen, doesn't get that hot. So even if it burns, it's not that big of a deal.
Tim Dodd
Right, Right. Because it's already detached.
Elon Musk
It's not as hot as the plasma that's hitting it.
Elon Musk
All right, well, let's see. I guess the car is. Okay,
Tim Dodd
So each tent's kind of a designated. One's like barrel section, one's nose cones and ones like one's just kind of the thrust pucks and stuff are.
Elon Musk
Yeah, like I said, it's. It is a constantly evolving thing. So.
Elon Musk
We've changed what occurs in each production tent and in the high bay and mid bay multiple times. But this certainly currently is focused on the nose when you're working.
Tim Dodd
You're working on a new high bay, too, right?
Elon Musk
Yeah, we're building a higher high bay.
Elon Musk
It's not like it's only a little bit higher than the current one, but it's much wider. And it has two gantry cranes that at one full width and depth.
Elon Musk
So, I mean, it'll feel like a lap of luxury compared to our current high bay. Like, how about how tall do you know Sorry.
Elon Musk
I don't know. Probably. Oh, it's like 100 meters.
Tim Dodd
Okay. And this one's.
Elon Musk
Yeah, this one's about 80. So they got the booster heights about 70. Although it was kind of funny. Like, technically we deleted half a barrel section from the booster, so it's technically 69 point something like 69 and a half.
Tim Dodd
You did that on purpose?
Elon Musk
No, it wasn't even me. I was like. The guy's like, hey, just let me know. We took a half at 70 meters. You have a half barrel, which is a pain in the ass. So they just deleted it. And I was like, cool, that sounds good. I mean, I randomly set the length at 70 meters. It's not like anything special about it.
Elon Musk
So is fate loves. I don't know. I don't know what's going on, but these certain numbers just seem to be recurring all the time. And so the booster is actually 69 point something and then it's booster four and ship 20. And this is all happenstance.
Tim Dodd
Right, Right. I love that.
Elon Musk
What the hell's going on?
Tim Dodd
Well. What? Oh, yeah, someone had figured out that. Oh, what was it? It was like. Oh, I don't even remember what it was. Something like you were 69,420 like days old or minutes old or something when you went on SNL or something like. It was like what? Something ridiculous. Yes. It was like the weirdest.
Elon Musk
No, I was born 69 days after 4:20, by the way. Oh, yeah. Come on. Come on.
Tim Dodd
This is ridiculous.
Elon Musk
It's ridiculous.
Elon Musk
I mean, what the hell?
Tim Dodd
Oh, man. This is insane.
Elon Musk
It's like. Am I an avatar in someone's video game? Yes. Oh, really?
Tim Dodd
Statistically, yeah.
Tim Dodd
You're probably doing pretty good at the game though. I bet you're like the top ranked player.
Elon Musk
Okay, well, that's something.
Tim Dodd
So what, do you have a name for the High Bay Bar yet?
Elon Musk
No, I guess we bounced around different names. We still haven't really made much use of it because it wasn't really critical path. So it's kind of just sat there. And the elevator, we need an upgraded elevator because we have like his construction elevator. We don't yet have a name nor have we used it, but we're making a progress. They're installing the grid fin.
Tim Dodd
Yeah. Let's see the grid fins up. And I like how they're now at. Is there. Do they just. Are you. I guess. Let me try and guess why you're gonna put them closer Together and not at 90 degree intervals. Is it because you can just roll, change your roll to change whatever axis you're trying to. If you're trying to pitch the vehicle, you're really only most of the time probably either doing pitch or yaw. You're likely not doing pitch and yaw when it's coming in for reentry.
Elon Musk
Well, actually, no. We're controlling on three axes. Now, technically you only need three fins to control on three axes, but you
Tim Dodd
can also roll if you need to change your yawn, roll 90 degrees to do pitch.
Elon Musk
Well, the control authority you need is much more in pitch than in any of the other axes. The amount of control authority you need for roll is practically nothing.
Elon Musk
And. But for pitch, you've got to basically push the booster down. So you're going to push this monster thing into the wind and it doesn't want.
Elon Musk
So the amount of pitchforce you need, that's like where you need the most amount of force. Yep. So having the, having the two pairs of fins, like, closer together, like more like an X Wing fighter.
Elon Musk
Allows them to contribute more in pitch. Yep.
Tim Dodd
Which then allows more glide or more. More of the airframe hitting the sides of the booster.
Elon Musk
You care about. Like, how much force do you have relative to how much force you need in a given axis?
Elon Musk
So you need a lot of force in the pitch axis. So that's where you want to bias your grip fin. Yeah. You could arguably say they should be biased even closer together than they are currently. Yeah. But this is a reasonable guess in between. Yeah.
Tim Dodd
Well, so this might end up pitching over more than the Falcon 9, because the Falcon 9 pitches pretty hard, but it's skinnier and of course has less control authority with the 90 degree thing. So maybe this could pitch even more and arrest more of its velocity. It's actually.
Elon Musk
You've got various things that are better. Some things that are better, some things that are worse. You can think of it like an airplane, like an empennage, where you've got a rudder. A rudder and an elevator. And if your elevator is far away from your center of mass, then the amount of force you need is less to change the angle. Just think of it like a seesaw. Yeah, you got a seesaw or a wrench. And if you have a long wrench, it's easier to turn than a short wrench. So if you have a shorter booster, a short booster is harder to turn than a longer booster. If you're depending on where the control surface is relative to your center of Mass. Okay. The center of mass is the kind of the. Where the seesaw, like it's see sawing around that center of mass. Okay. And center of pressure. You have two things. Basically it's like it, basically this sounds, it sounds more complicated than this. It's basically a teeter totter or seesaw. That's where there's a center of pressure and a center of mass. And it's going to basically just rotate around that. Yep, yep. And so if you've got a long stage that, where the grid pins are far away from your center of mass, then you need less force to turn it.
Elon Musk
Yeah. So basically.
Tim Dodd
Gotcha. Gotcha. That makes sense.
Elon Musk
Yeah. If you had like a really short stubby thing, it would actually be quite hard to move it.
Tim Dodd
But at least as far as the fineness ratio, this has a lot more potential since it's wider to actually use atmospheric, use the atmosphere to slow down before it even has lightest engines. Because like, you know, New Glenn has those strakes on the side and it looks like they're really planning to almost, you know, fly the thing for a little bit, you know, at a pretty high angle of attack compared to the relative wind stream to really let the atmosphere slow down the vehicle as much as possible. You know, you guys are pretty. Compared to Falcon 9 is a lot finer or a lot less fine ratio. It seems like you get a lot more lift out of the thing.
Elon Musk
Realistically, this is going to come in at something close to terminal velocity, right? Oh so yeah, yeah. Because you're trying to get to a precise point. So it's very difficult to do a fast pitch up maneuver and, and also get caught by the tower.
Elon Musk
Like if you've got a very big landing area that's. Then you could do that maybe. But if you want to land in right. You can't do like a sudden pitch up at the end and then you've got sort of pretty big moments of inert like this. Big things don't move like small things. Right. So like you don't see a supertanker dashing around like a speedboat.
Elon Musk
This is like in a rocket form of a super tanker. So it doesn't move fast. It's like way bigger than a whale. So. Yeah.
Elon Musk
So it's just not going to move fast. Although ironically, liftoff will be weirdly fast. Yeah, but ye big rotating things always move slower than small rotating things, you know.
Elon Musk
So it's, it's. Yeah, like I said yeah, there's, there's a lot of potential improvements. I mean, Yeah.
Tim Dodd
Man, oh man, wasn't that an awesome conversation? Now, in part three, we're going to be taking you down to the launch pad and you're going to be able to see Elon just walking around at work. It's super fascinating. Again, thank you, Elon, for spending so much time hanging out with me. I'm glad that you had fun and it looks like maybe we'll be able to do this again. Again. You know, I'm game for that. And SpaceX, thank you so much for allowing me to share all this awesome stuff with everyone. But I owe a huge thank you to my Patreon supporters for helping make this and everything we do here at Everyday Astronaut possible. If you want to gain access to some exclusive live streams and also our awesome Discord community where we talk about everything space flight all the time, head over to patreon.com everydayastronaut and while you're online, be sure and check out our awesome web store where you'll find shirts like this, the full flow stage combustion cycle shirt and the hoodie and the Aerospike shirt and the rest of the schematics collection or the Future Martian collection. You'll find lots of fun stuff@everydayastronaut.com shop. Thanks everybody. That's going to do it for me. I'm Tim Dodd, the everyday astronaut, bringing space down to earth for everyday people.