Starbase Tour with Elon Musk [PART 2]

- 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 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 and the description is below for that at www.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 COMS might not want all this- - Oh, yeah, just... It just can't be any more than people are already getting from- - [Tim] That's true. - Telephoto lenses.

- [Tim] That, which is pretty much everything. - And frankly, if some fool wants to copy this design, go for it. (Tim laughs) I mean, Raptor 2 is a giant improvement over this. - [Tim] What's the big simplifications you're hoping to have? - Well, maybe I shouldn't tell you all the secrets. (Tim laughs) We have funny things on the... We've got Pikachu over there.

- [Tim] (laughs) I love that. - [Elon] Hello again. - [Tim] Hello again. So that probably, I assume that means it's flown. Is that a flown one? (Elon laughs) - I don't know if this one's been flown.

- [Tim] Geez. This really does look like that thing with all the NK33s. Those videos of- - Yeah, yeah, exactly.

Engines that came back from the cold. - [Tim] Yes, seriously. It literally looks like that. This is insane. Man, that wrap vent is big.

Geez. - Yeah, I won't tell you all the secrets. (Tim laughs) You'll be able to see the difference very clearly. - [Tim] Okay. - And I guess,

since the engines are... It's hard to have people not see them. - [Tim] Yeah. - They will... The Raptor 2 is visibly cleaner than Raptor 1. This sort of maze of plumbing and wiring doesn't exist on Raptor 2. - [Tim] Although, it's already slimmed down a ton from like- - Yeah, it used to look like a frickin' Christmas tree.

- [Tim] (laughs) Yeah. - You couldn't even see the engine for all the stuff that was around it. - [Tim] No, you really couldn't. And now it's like, especially around the turbines and stuff, and the free burners, I mean, that used to be a whole, there's sensors every two millimeters.

- [Elon] Yes. - [Tim] So, Rap-Vac or Raptor-Vac has it's own regen channel on the extension, it looks like. - [Elon] Yeah. That's a steel tube wall, raised steel tube wall. - [Tim] 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] No. Throat's the same. - [Tim] Throat's the same?

- It's just the part after the throat. The diverging section has different angles. Basically it's following a rail counter for a higher expansion ratio. - [Tim] Yeah, yeah. What is the expansion ratio again? Is it like 150 or something? - No. Man, I think we were...

So this is actually, I think we were around 80-ish. - [Tim] Oh, okay. - But we wanna get to, we wanna do a little bit better. Maybe 90.

- [Tim] 'Cause you're already getting like, 380 ISP out of that thing, aren't you? Or I mean, sorry, yeah, 380. - 380's the aspirational number. - [Tim] Okay. - But we should be able, I think we will get like 377 or 378. - [Tim] Okay, okay.

And how are those coming along? It looks like obviously you've got a third one here. You've obviously made at least three. - [Elon] Yeah. - [Tim] S-20's gonna have three. - [Elon] Yes. - [Tim] Yes.

Geez. - All the engines will have the same pumps and thrust-chamber assembly. It's really just building it one, sort of one variant that has a big nozzle and one variant that doesn't have thrust vector control actuators. - [Tim] Okay, okay.

And that's gonna be the difference between the R boost and the? - Yeah. I mean, it's basically the same engine, minus PVC. - [Tim] Gotcha. So, the outer shells that you're working on for the GSE are 12 meters. - There's a Raptor

without the stuff; looks practically naked. - [Tim] (laughs) you're like, actually that's secretly version two. It's super simple. No. - [Elon] Version two will look a bit like that actually. - [Tim] Really?

- [Elon] It's very tight. - [Tim] Really? - [Elon] Yeah. - [Tim] I mean, again, when you look at some of those Soviet engines, they were also incredibly simple looking. I'm guessing they just obviously didn't have 'em wired to the gills with electronics, though, either. You know? - They didn't. They simply didn't, back in those days, they did not have good electronics.

- [Tim] Right. - So there's nothing to- - [Tim] There's nothing to wire up. - Yeah. - [Tim] Yeah. How much, I feel like 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? How do you teach that culture even, that it's okay? When you're not even trying to like... You know, SN-8 is a perfect example. You weren't trying to do a mission. You're just trying to get data out of the thing.

- Yeah. We have just a fundamentally different optimization for Starship versus say, like the polar extreme would be Dragon. Dragon, there can be no failures ever.

Everything's gotta be tested six ways to Sunday. There has to be tons of margin. There can never be a failure ever for any reason whatsoever. - [Tim] Yeah.

- That's 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. - [Tim] Right. - And then for Starship, it's 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. Rapidly reusable rockets.

- [Tim] It's a big deal. - Yeah. That's the fundamental Holy Grail for making life multi-planetary. - [Tim] where do you think the Space Shuttle failed in being, and definitely rapidly would be a word you've got to scratch off the list- - Yeah, definitely not rapid. - [Tim] 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? - The Space Shuttle had almost no room for iteration because there were people on board.

So you couldn't be blowing up shuttles. So that's a big problem. - [Tim] They did very, very little. - Very little. In fact, a 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] 'Cause the design froze. - Yeah, 'cause it's like... Yeah. I mean, there was a risk/reward asymmetry. So, big punishment for, if you make a change and something goes wrong, big punishment.

If you make a change and it goes right, small reward. - [Tim] Yup, yup. - So, the issues with the O-ring and then with the insulation coming off and hitting the wing, they had seen this before. - [Tim] Yeah, they were known. - They were known issues. Because it had worked before, they're like, well, it worked before.

Russian roulette works before. - [Tim] Right. (chuckles) Oh God. - [Elon] Look, I've pulled the trigger so many times.

There must be no bullets in this gun. - [Tim] It must be no problem. - [Elon] Yeah. Anyway, it's hard to iterate, though, when people are on every mission. You can't just be blowing stuff up 'cause you're gonna kill people.

Starship does not have anyone on board so we can blow things up. That's really helpful. - [Tim] Do you have any considerations yet on any kind of launch escape? Are you just hoping that by the time you put people on it, you've flown it say 100, 200 times, and you're familiar with all the failure modes, and you've mitigated it to a high degree of confidence. Or what's your? - Yeah. Larger scale, 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 and everything's okay. 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. 'Cause the typical launch escape system is a solid rocket motor on the tip of the capsule, which then has to be...

- [Tim] It has to be jettisoned. - It has to be jettisoned on every mission. So, if it's not jettisoned, the crew dies. - [Tim] That's a failure mode, right there. - 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 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, I think, a safety improvement. There's no escape system coming back to Earth. That's doesn't exist. - [Tim] Right. - And then, you can't have an escape system on the Moon or on Mars. - [Tim] Or on Mars. Yep. - Yeah. You can't have something pop off and then have shoots drop.

There's no atmosphere. - [Tim] Right, right, right. - And then Mars has a very low density atmosphere. So, it'll just hit the ground supersonic.

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. - [Tim] Right, right. So you might as well- - Kind of pointless to do it on Earth.

Just fly it a lot. - [Tim] Right. And I never really thought about that. 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 know? (tools whirring) - [Elon] Yeah. - [Tim] So, let's see. What? Oh, those are the vacuum mounts, aren't they? - Yeah.

- [Tim] Wow, that's cool! - Yeah. I mean, this sort of stuff, it's very much version one. - [Tim] Yep. - It'll be a lot better with the next iteration.

- [Tim] Well, a lot of people will ask me, 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? - Yes. - [Tim] And you just simply have to start, you have to force yourself to start.

- Yeah. - [Tim] Then you improve from there. - Exactly. - [Tim] Man. Are you pretty used to the heat? I feel like it's, it's pretty hot out here. - It is hot.

I mean, this is the worst. This is like summer, you know? - [Tim] Right. - It's just the worst of it. - [Tim] Yeah. - But it's not that bad. Just pretend you're in Hawaii.

- [Tim] Right, there you go. (Elon chuckles) So, speaking of Shuttle. - I mean, I think it's a cool view. - [Tim] Oh, it's a really cool view.

And thermal protection, it seems like you guys have made some, I mean, it looks like S-20 is gonna 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? - We'll find out. (Tim laughs) - [Tim] Has it been holding up pretty good, at least on the low altitude stuff? - Yeah. - [Tim] As far as

the mounting points and stuff like that. - I mean, it's still there. I mean, you can see the videos. - [Tim] Yeah. - It takes off with the tiles

and it lands with the tiles. We have, I think, a good attach mechanism. It 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.

It's quite a tricky thing with the tiles 'cause the tiles are essentially a ceramic. And they're attached to a metal substructure that is changing in temperature dramatically. It'll be a 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 Alish 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. There's a lot of expanding and contracting going on all over the place. I think one of the big questions is, are these tiles, are we gonna have a crack or a gap in the tiles? Like, if they bang into each other, they're ceramics, like a coffee cup is ceramic.

So, if you bang two coffee cups together it's usually bad. - [Tim] It's not good, yeah. - If the tiles bang each other and crack, this could result in a failure on entry. So, I think there's a huge question of like, when we get the ship to orbit, is it able to make it back through Earth's atmosphere? 'Cause it's coming in like a meteor. - [Tim] Right, right. - It's like a blazing hot meteor.

Will the heat shield stand up to it? Or if there's any crack in the armor, it's toast. - [Tim] Yeah, yeah. - So, hopefully we at least find out where the crack in the armor is. - [Tim] Right, right. - That would be great. - [Tim] And then if you have to, you can make some thicker or smaller, or iterate to that degree of where you find those failures again. - Yes.

- [Tim] How will you know? What if something just goes... What if the first orbital attempt just goes totally, it doesn't even make it in for reentry and it's just a million pieces of the bottom of the ocean? How will you know where it failed? - We have temperature sensors. Probably need some thermal images inside the tanks.

So, just like IR cameras. - [Tim] So you can see if a certain section's getting real hot. - Yeah, our cameras on the inside will show you what the backside temperature is. - [Tim] Yeah, yeah, it'll let you know if a leak propagated. - It's only gonna pop

if the backside temperature... Frankly, I'm not sure. In fact, I take that back. If you just have a camera-camera- - [Tim] Yeah, you'll know.

- Visual, you'll see if something's glowing white-hot, okay, that's bad. (Tim laughs) That's the bad part, right there. So, you don't even need a thermal image, frankly.

The steel will glow white-hot before it melts. - [Tim] Right, right, right. (laughs) You'll know. - You'll know. It's not subtle. - [Tim] And the very first orbital test, again, it kinda seems like... 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'll deorbit? - No, it's getting to orbital velocity.

But it's not circularizing it's perigee. - [Tim] Yes. - It basically goes three-quarters of the way around the Earth, but because we didn't raise the perigee, the atmospheric drag will put it in.

- [Tim] Yup, and the velocity will probably be greater, reentry velocity will be greater that way or similar. - Similar. It's not a huge difference. It could easily, if you just puff the attitude control thrusters or the aldris gas, the aldris gas alone could put it into orbit. So, raising perigee slightly is easy.

- [Tim] Yeah. - It's remarkably easy. If you just wanna raise it a little bit. - [Tim] Are you hoping to actually recover the first one? - No. - [Tim] Or try to even land. I mean, is it gonna try to fire its engines? - Our goal with the first one, for the first orbital launch, our goal is to make it to orbit without blowing up.

- [Tim] Yeah. - That's our goal. - [Tim] Yep. - And frankly, if the booster even does its job and something goes wrong with the ship, I'll still count that as good progress. - [Tim] Yeah. - Basically, actually, to be totally frank, if it takes off without blowing up- - [Tim] (laughs) Right. - Blowing up the stand,

stage zero, which is much harder to replace than the booster, that would be a victory. But please do not blow up on the stand. That's my number-one concern. - [Tim] You keep calling it, you're calling the stand stage zero? - The launch system. - [Tim] Really?

The ground, GSE, the tower and all that stuff? - Stage zero, yeah. - [Tim] Okay, yeah. I got so spoiled now with, again, Soviet nomenclature. It's like, there's zero for the boosters.

- Really? - [Tim] The core is one. - Okay. - [Tim] And then what I would call the, wait. No, sorry, opposite: the boosters are one, core is two. 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, second stage, and they're like, no, no, that's third stage. You know? - Well, stage zero, the launch system, the launch mount, flame diverter, sort of. - [Tim] Yep, sort of. - The big tower. The propellant farm.

All the lines and everything, that's stage zero. And it's very hard. - [Tim] Yeah. - It's harder for us to make a stage zero than to make a booster or a ship. - [Tim] Okay. - So I hope. - [Tim] Hopefully it doesn't blow up.

- Yes, that would be great. (Tim chuckles) And then, the best-case outcome for the first flight would be that the booster does its job and also is able to relight the engines, and it's gonna splash down in the Gulf. - [Tim] Only 20 miles out or something, right? - Yeah, not far. - [Tim] Relatively. - And then the ship or upper stage is gonna come in just off the coast of Hawaii, near a military base there. And so, we'll splash down in the Pacific. - [Tim] Yup, yup.

So, again, to reiterate, on the first launch you won't, the booster, you're gonna just use the gas venting to orient it for re-entry. You will do boost-back burn on the first one too, right? - Let's just say it's an evolving situation. - [Tim] 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. - [Tim] Yeah.

- So, yeah, I mean, probably it's a boost back. Basically you want to stimulate the landing but not, not have it be too close to land, so it doesn't take out stage zero. - [Tim] Right. Yep, yep. - We want to say, basically, can we position the booster precisely such that if it had landed next to the tower, or if it come to a halt next to the tower could the arms have grabbed it? - [Tim] Yes.

- Mech-zilla. - [Tim] Mech-zilla? - Mega-zilla. - [Tim] Mega-zilla? - Mecha. - [Tim] Mecha-zilla, okay. Yeah, like a giant mech. - Yeah kinda like mecha-zilla.

- [Tim] What's the plan? It just comes and sits then on the grid fins and or that little arrester thing? - No, those little tiny arms. - [Tim] That tiny little T-Rex arm is gonna hold the whole- - Yes, there's two of them. But those things can take a lot of load. - [Tim] And then it's just literally a flat, a flat arm kind of like this that? - I mean, this is one of those things, it's hard to keep a secret when it's right there. People can just take zoomed up photos.

Drive past it and take a high-res photo close up. So, it's not exactly gonna be top secret. - [Tim] Right, right. - This is the first real big rocket development that's been so close to a 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] That brings up, I always keep wondering, we're seeing this insane pace, we're seeing all these crazy things happen. How much of that is normal, at least as far as SpaceX goes? Or how much of that is just because we're actually seeing it? Like, for instance, when you were developing Merlin and Falcon 9, were you blowing stuff up this much doing things so crazy fast paced? Or is this also fast-paced, but now we're also seeing it all so it's hard to compare? - Well, I mean, this is definitely a case where we are washing out laundry in public. - [Tim] Yeah, yeah.

- There's always dirty laundry in any program. It's really a question of whether it is seen or not. Not is there dirty laundry. - [Tim] Right, right. Yeah. (Elon laughs) - Every program's got dirty 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- - [Tim] Right. - Which then have to be stored and they look awesome, but you know, we don't want 12 of them. It's gonna look bizarre and where will we put them? - [Tim] Yeah. - So, since we were making a rapid iterations with each... Basically every single ship and booster has had significant iterations.

You either either want it to blow up or, the early ones, you want them to blow up, or you're gonna have to find a place to store them. - [Tim] Right. - 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. - [Tim] Yeah.

- It's not possible. - [Tim] Yeah. - You have to go close to the edge on margins. - [Tim] Right, right. - And there's a recursive factor to mass.

So, if you add, say an extra ton of heat shielding, now you also need more propellant to get it to orbit, and you need more propellant to deorbit it, and you need more propellant to land it. And the structure now has more load, 'cause it's carrying that extra ton of heat shield. So, this applies at any given time, there's a recursive value.

So, in order to achieve the same payload, you have to... Each ton is basically almost like adding two tons, when it's fully considered. - [Tim] Definitely. - So, I think we've calculated it to be like a 1.8 factor, but I think it's probably we're forgetting something so it's closer to two. - [Tim] Yeah. - So, every one ton of mass begets an extra ton.

- [Tim] Yeah, yep. For instance, what's S-20's dry mass? Kind of looking like, where are you at right now? Are you like, 120 tons? Or are you? - I actually don't know the exact mass of 20. We'll know it when we weigh it.

- [Tim] Yeah. - There's a lot of parts that have not been weighed. (Elon laughs) - [Tim] Yeah. - So, what is it actually? I mean, I hope it's not too insane.

Ideally it's... It's dry mass is hopefully not much more than a 100 tons. - [Tim] Really? - Yes, but then if you say dry, do you mean not counting the air inside it? - [Tim] (chuckles) Right, right. - Which by the way, the air, actually air mass is non-trivial. - [Tim] No, it's not. - (chuckles) 'Cause it's such a giant volume.

And then do you mean dry? Do you mean with propellant residuals? And Alvis gas, which is at several atmospheres? - [Tim] Right. - Which mass are you referring to? - [Tim] Which dry mass, right. - Sometimes in these things, they'll play games with the, when you say thruster weight of a rocket engine, so the thruster weight of the rocket engine with or without residuals? That's a big change.

- [Tim] Or with or without gimbal is something else that I've heard people debate. - Yeah. - [Tim] Yeah. - Merlin is, I'm pretty sure by any standard, you know, I think it's probably the best thruster weight of any engine. Because it's just so far, we really pushed the GG cycle engine to the... It's like A-plus for GG cycle architecture.

But GG cycle architecture is not an A-plus architecture. - [Tim] Architecture, right. - Full flow stage combustion, A-plus architecture. But with the new architecture, we won't get it an A-plus within that.

It's like in gymnastics, you know, you'd like to say, how hard is your program? And then what grade do you get in the program? - [Tim] In the program, yeah. - That's kind of how things work here. - [Tim] What would you say version two's gonna come in at? If you were to rate 'em? - I don't know. I'd say it's like, B-plus. - [Tim] Okay. - Something like that. - [Tim] Yeah. So, good enough for now.

But of course, reiterate. - Yeah. Raptor 3, Raptor 4, Raptor 5. By Raptor 5, it'll be an A-plus. - [Tim] Yeah, yeah. Should we walk through here and check out what's going on in here? This is just a nose cone being assembled.

It's not that it's showing? - [Elon] This is our new and improved nose cone. - [Tim] Oh yeah, it's just straight. There's no cross section. - If you look at that nose cone over there, that's made from stamped sections. You can see that's three rows of stamped sections. This will be made of two rows of stretch formed.

- [Tim] Wow. - [Elon] And you can see it's just way smoother. - [Tim] Yeah.

- This is stretched over like a big mandrel. So just take a big sheet of steel. And if you just stretch it over this giant tool. - [Tim] Right, right, right. - And then you can have things that are way bigger.

Like you can't fit this in a stamping press. This is way too big. That's like basically about as long as you can fit in a stamping press.

You cannot fit something this giant. Well, you can technically make some totally special case stamping machine that doesn't exist. But since you only need a single sided, it doesn't have indentations or anything. 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] And this isn't the cargo. It's not complete yet, but it had that opening on the one side. That's not because you were working on the door.

The jaws yet, right? - Yeah, I actually stopped work on the door, the faring door. - [Tim] Okay. - We're gonna focus on getting to orbit. We don't need a door. It's like, we need to be super focused on getting to orbit then super focused on getting the ship back, then we can worry about doors. - [Tim] Okay. - It's just an unnecessary complexity.

Is the door necessary to solve the problem? No. Will we use this, the first 10 or more that get back from orbit, we probably won't fly them again. Or maybe once or twice, but they're not gonna be in storage. For Falcon 9, and even the Block 5, So for Block 5, which is more like version 7 really. But we don't even want to use the early Block 5s. Even those were a pain in the ass.

And we prefer to retire them. So when we have a mission that requires an expandable 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. - [Tim] Wow. - Reality is, the early ones are gonna be amazing lawn ornaments.

I mean, as good as a lawn ornament gets. But they will not be nearly as good as the ones that follow. So then why keep them flying? - [Tim] They're not gonna be putting any payload up. You don't even need to worry about it yet. - Yeah, so we're just gonna retire the early ones anyway.

Why have a door on a thing that's never gonna fly satellites anyway. - [Tim] How is the butt to butt refueling going? 'Cause that's gotta be a pretty early consideration. 'Cause you're probably gonna want to start testing that. - No. - [Tim] No?

- No, we're gonna get to orbit and back first. - [Tim] Okay. - We don't need orbital refueling. Unless you're going to the Moon, you need orbital refueling. Going to Mars, you need orbital refueling.

Delivering satellites to Earth orbit, you do not need orbital refueling. - [Tim] Right, right. - So just punt that 'til later. - [Tim] Okay.

- I'm not sure it'll be the butt to butt. It might be something different. We switched the propellant full drain lines to be side. So, coming from the side. - [Tim] Not up through the booster anymore? - No. It was adding a bunch of stuff to the booster.

And then we're flying it every time. If you can move mass to the ground side, it's better to move mass to the ground side. - [Tim] Right, right. - That's why we took the legs off the booster and just have the tower catch it. - [Tim] Are you thinking about doing a tower catch? - Which sounds mad. - [Tim] Yeah, I know! - I know it sounds insane.

But when I suggested that, people thought I lost my mind. Which I'm like, maybe I have. But I think it might take a few kicks of the can, but we'll get it right. It's just, 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, windy situations; it's very windy around here. - [Tim] Yeah it is. - So, you're gonna pick up this booster, you're gonna put it onto a stand with precision.

Then you've gotta pick a ship up and put it up on top of that. 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 mech is armed, pick up the ship and put it on the booster. - [Tim] Okay.

The mech-zilla arms are the ones that are gonna be picking up the ship, not the crane? - Okay, so... (Elon chuckles) Very important to appreciate that everything you see here is a work in progress. - [Tim] Right. - And what is said last week may be untrue next week. - [Tim] We've seen that a few times.

- Yes, it could be that we're actually just literally mistaken, a miscommunication. Any one 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 we're gonna do that with a crane. - [Tim] Yeah. - Yeah. (Tim laughs) Marvin the Martian right there. - [Tim] I love that.

- The first one we're gonna stack with a crane. 'Cause otherwise we'd have to wait for all the mechanisms to work. We're assembling the arms and basically putting mech-zilla together.

But in the meantime we could be launching. So let's not wait for the tower to be completed. We've got 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, you know, just like, do we have the hull downs work? Or the launch mounts, I should say. It's really quite a complicated launch mount. It's got basically 20 mount points.

And you've got to line those things up and then put the booster on it and have the, you know, does it fit? Okay, it won't fit, basically. Now we gotta adjust it. That launch ring is 370 tons. - [Tim] Oh my God! - And it's gonna tweak, you move it from one place to another, it tweaks.

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 fit the booster. So, we wanna do that soon. We should be done with this booster, I don't know, next week. - [Tim] Yep.

Wow. - [Elon] So then we want to mount the booster next week. - [Tim] That's gonna be insane to see. - Yeah. We're gonna try to put the ring on the stand, the launch ring on the stand tomorrow.

- [Tim] Wow. - But we may not succeed, we'll see. Probably the second flight we'll use, I mean, it's probably like the second flight we'll use the tower.

- [Tim] Okay. Second flight, oh, so the first flight might still just use the suborbital pad? - No, it's gonna use the, it has to use the orbital pad. The suborbital pad cannot take the full weight of the stack. It's gonna 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. We gotta launch it from the super beefy stand.

But we don't want to wait until everything's ready with the tower, just to stack. - [Tim] Okay, so, how will you secure it then when it's stacked? Just drop the Starship on top? - Have the crane hold it. - [Tim] Until it's launch time and then? - We do need the QD arm to work. - [Tim] Oh right.

So that can be a stability thing. - Exactly, it holds it, it stabilizes it, and transports propellant. If we don't have that, we can't load a prop on the ship. - [Tim] Right, right, okay.

So that has to be complete, but not necessarily the arms and everything else going on at that point. - [Elon] Yeah. - [Tim] Dang. - [Elon] Yeah, exactly. - [Tim] At this point- - I mean, like I said, 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 not ready in time, we'll use the crane. - [Tim] Okay. - Yeah. - [Tim] So at this point in development, what things are you being kept up by at night? Like, what's the thing you're like, oh, we just need to do this or this better. Or we really, I can't sleep 'cause I'm not, we haven't figured this out yet. - I'm sorry? - [Tim] Yeah, so, what things are just totally keeping you up at night at this point? What's the thing that you feel like you still have to solve at this point? - I mean, there's a long list.

- [Tim] What's at the top of that right now? For you at least personally. - 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 schedules. I mean, if I wasn't optimistic, I wouldn't be doing the crazy things that I'm doing.

- [Tim] Right. - [Elon] So I must have like, I don't know just pathologically optimistic, I suppose. (Tim laughs) - [Tim] Wow, that actually, just look at that.

- [Elon] Yeah, it looks like dragon scales. - [Tim] That is incredible. - [Elon] Doesn't that look cool? - [Tim] It's actually coming together a lot cleaner than- - [Elon] It totally looks like dragon scales, I think. - [Tim] It really does. - [Elon] Yeah.

- [Tim] And it's so much tidier and cleaner looking than I thought. - [Elon] Yeah. There's a few broken tiles, but overall it looks cool. - [Tim] That's incredible, wow. So, I guess, the joints is one of those things that the community has always wanted to know about. I guess the good thing is 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 flap joint itself 'cause it's kind of already- - No, actually, unfortunately we do. I think we have significant... Take a lot of what I'm saying with a grain of salt. I often am wrong. Sometimes I'll say something and it's wrong. (Tim laughs) I think we have a design error with the, with the non-moving portion of the forward flaps.

- [Tim] Okay. - Because the reason we have... The flaps and the static arrow, basically the unmoving portion of the flaps are there to do two things: to balance, rebalance the ship so it doesn't come in engines first. Otherwise, the center of mass is quite low. - [Tim] Yeah.

- And it will come in engines first and burn up the engines. - [Tim] Yep. - So, first you have to rebalance it so that in a hypersonic stream, you're doing roughly sort of like, a 60 to 70-degree angle of attack. Because you're flying a trajectory that minimizes- - [Tim] Peak heat. - Peak heat. But you don't care about total heat load.

You just care about minimizing your peak heat. - [Tim] Because you have a good insulator here. And you're not ablating. - Yes, exactly. So, if you have an ablative heat shield like Dragon. Technically Dragon is fairly reusable actually, 'cause it's sort of like a brake pad. You can fly it many times 'cause it's got so much margin.

But PICA literally means phenolic impregnated carbon ablator. - [Tim] Yep. - That's the Dragon heat shield. So, Dragon was like, hey, let's have a, give me 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? The heat pulse moves through the tile and then reaches the back to where it's bonded to the carbon fiber composite sandwich structure.

- [Tim] Yep. - 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. - [Tim] Really? Okay. - You start having

these things like- - [Tim] Right, flying off. - Potentially, 'cause they're low density. So they they're pretty...

Intermittently it's kind of a corner case. The graying heat shield tiles are way over thick, not because of how much of the heat shield will be ablated, 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] Wow. Yeah, interesting constraint at the end of it all.

- Yeah, so if you just have a lot of heat suddenly, that's actually better for Dragon. High peak, low total heating. - [Tim] Yep, yep, yep. So its reentry profile is totally different, too. - Yeah. - [Tim] It can come in steeper

as opposed to this- - It's gonna come in, Dragon wants to come in real steep. The lift over drag ratio is low for Dragon. 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 off-centered center of mass, then you can control it because it has a small lift vector because the gumdrop is tilting into the wind slightly. It's quite low. And actually, L over D is a function of mach number.

People always go, well, quote an L over D number. But like, okay, what mach is that? And it's usually some sort of reference mach number. But your L over D is complete trash at mach 20. It's garbage, nothing basically. So it's like, L over D at what mach number? Anyway, it's got a very low L over D. 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. You have a landing ellipsoid because your accuracy longitudinally is less than your accuracy left to right. So, you're changing lift 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 lift point? 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 points and then your lateral point is pretty easy to tune because you have a lift vector going left and right.

- [Tim] 'Cause it's not so much, people might think, 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 your actual velocity. And where you end up arresting your velocity is where you're gonna drop it to the ground pretty much, more or less. - Yeah, I mean, I think it's just very important for people to appreciate that there's a very gigantic difference between orbit and space. - [Tim] Right.

- It is actually relatively easy to get to space. But it is very hard to get to orbit. - [Tim] Right.

- And then you say you want to get to orbit and come back. This is easily 100 times harder than getting to space, maybe 1000; so much harder. That hardly anyone's even, you know, only a few countries have been able to do it. - [Tim] Right. - You know, whereas Burt Rutan went to space twice.

What was it, like, 12 years ago? I don't know, it was a while. What, 15 years ago? - [Tim] Yeah, 2004, 2005. - Yeah, it was like 15 years ago.

He went to the border of space twice, and didn't even scorch the paint. It's really not very hot if you didn't even burn the paint. - [Tim] Right, that's true. - Yeah. - [Tim] That's true.

(machine beeping) - Whereas, this needs really intense heat shielding or it's gonna get to, you know, blow up basically. - [Tim] Yeah, yeah. It's crazy to see now, honestly.

So, is there some considerations to make the fixed? Can we go out this way or is it? - Yeah, I mean, just don't let anything drop on your head. - [Tim] All right, deal. So there's another barrel section of S-20. - I mean, it looks a little garage shop, to be frank. But it's like weirdly super advanced technology with garage shop. (Tim laughs)

- [Tim] Well, it is very unique of you guys to basically build the rockets first and then start building a factory around it. You know? - Yeah. The production system is the actual hard thing. - [Tim] Right.

- The rocket design is relatively easy compared to the factory. And these tiles are actually made in Florida at a SpaceX factory we call the Bakery. In Florida, it's next to a Ron Jon's.

(Tim laughs) - [Tim] What's the future for Florida with Starship? Are you gonna get it flying 100%, get it all figured out basically? At least get orbital version ready and then start setting up shop in Florida? - Yeah, I think we wanna kind of iron out the major issues here. 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] Next to Ron Jon's? - Well, technically it's next to a Ron Jon's distribution warehouse. Literally, I was like, is that a surf shop? Yeah, well, maybe it's a factory, I don't know, but I just got a Ron Jon's logo. But the factory, the SpaceX heat shield tile factory is quite big. It's not tiny. 'Cause you need to make a lot of these tile.

- [Tim] 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.

- [Elon] (laughs) Yeah. And you can see we're figuring it out. - [Tim] But I'm surprised, though, even as the area tapers, it's not, I would have thought- - Mara's head of heat shield engineering. It's like, I'm gonna text him like, yo man, what's going on? - [Tim] It doesn't seem like there's a ton of unique.

They mostly look uniform, which obviously will help with- - [Elon] Yeah, they're not all uniform. - [Tim] A lot more than the Shuttle. What's your expected, what are you hoping to get for reuse out of these things? - Oh, I mean, no meaningful limit. As many as you want. (machines beeping) - [Tim] There we go.

We got right back into camera-ception for you there for a second. Camera inside of camera. (machines beeping) - Yeah.

There are different shapes of tiles. You can see some of them at the border there are square instead of hexagons. - [Tim] Yep. - And then, because the static arrow is, it's still seeing actually a lot of heat, basically the plasma is hitting the surface and then it's moving around.

It's got to somehow get past it. You've got super heated plasma hitting 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's, you have to protect the hinge. This is if you said like, okay, what's highest probability of failure on reetry? It's probably the hinge of the flaps. So, the rear hinge and the forward hinge of the flaps.

'Cause 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 we have to seal against, against the tiles. So, the tiles are ceramic, like a seal against dinner plates that are super hot.

So you can't use rubber. - [Tim] Right. - So it's gotta be a metal seal, and with a torturous path. - [Tim] Have you thought about, back in the day, you talked about transpirational cooling. - Yes, so, that's one of the things you could throw at it is transpiration cool the joint. - [Tim] That would be so cool. I just want to see it bleeding methane, honestly.

- It'll definitely help. - [Tim] 'Cause you can kind of purge that joint with a higher-pressure gas. As long as it's higher than the ambient air stream or the plasma stream, it will create a thermal barrier. - 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. 'Cause actually, even the burning methane is like, with air, because air is only like, 21% oxygen. If you ask me, what are you breathing, they think they're breathing oxygen.

You're breathing nitrogen with some oxygen. - [Tim] A little argon. - And some argon and some trace gases. 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] Right, right, 'cause it's already detached from the vehicle at that point. - It's not as hot

as the plasma that's hitting it. - [Tim] Right. - Yeah. - [Tim] Wow. - All right, well, let's see. I guess the car is? (woman speaks off mic) Okay. (machines beeping) - [Tim] So, each tent's kind of a designated...

One's barrel section, one's nose cones, and one's, one's just kind of the thrust pucks and stuff? - Yeah, like I said, it is a constantly evolving thing. 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. - [Tim] You're working on a new high bay, too, right? - Yeah, we're building a higher high bay.

- [Tim] Uber high? - It's only a little bit higher than the current one, but it's much wider, and it has two gastric cranes that run full width and depth. - [Tim] Okay. - I mean, it will feel like the lap of luxury compared to our current high bay. - [Tim] Like how about tall, do you know? - Sorry? - [Tim] About how tall? - I dunno, probably, oh, like 100 meters.

- [Tim] Okay, and this one's? Like 80 or something. - Yeah. This one's about 80. The booster height's about 70. Although it's kind of funny.

Like technically we deleted half a barrel section from the booster, so it's technically 69 point something. (Tim laughs) Like 69 and 1/2. - [Tim] You did that on purpose. - No, it wasn't even me. I was like, the guy's like, hey, just let me know, 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, sounds good. I mean, I randomly set the length of 70 meters. It's not like any special about it.

- [Tim] Right. - I guess 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. - [Tim] Yes. - So the booster is actually 69 point something. And then it's Booster 4 and Ship 20. - [Tim] 20. (laughs) - And this is all happenstance.

- [Tim] Right, right. I love that. - What the hell is going on? (Tim laughs) - [Tim] Oh yeah, someone had figured out that, oh, what was it? Oh, I don't even remember but it was something like you were 69,420 days old or minutes old or something when you went on SNL or something. - What? - [Tim] It was some ridiculous. - Are you serious? - [Tim] Yes, it was the weirdest- - You know I was born 69 days after 4/20, by the way.

- [Tim] Oh yeah. (laughs) Come on! - Come on. - [Tim] This is ridiculous. - It's ridiculous. - [Tim] That's so funny.

- I mean, what the hell? - [Tim] Oh man. This is insane. - It's like, am I an avatar in someone's video game? - [Tim] Yes. - Oh really? - [Tim] Statistically, yeah. - Okay. (Tim laughs)

- [Tim] You're probably doing pretty good at the game, though. I bet you're like, the top ranked player. - Okay. Well, that's something. (Tim laughs)

- [Tim] Do you have a name for the high-bay bar yet? - [Elon] No, I guess we've bounced around different names. We still haven't really made much use of it because it wasn't really a critical path. So it's kind of just sat there. And the elevator, we need an upgraded elevator 'cause we have this construction elevator.

- [Tim] Right. - We don't yet have a name. Nor have we used it.

But we're making good progress there installing the grid fin. - [Tim] Yeah, looks like the grid fin's up. And I like how they're now... Let me try and guess why you're gonna put 'em closer together and not at 90-degree intervals. Is it because you can just change your role 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. - Well, actually no. We're controlling on three axes all the time. Now, technically you only need three fins to control on three axes. - [Tim] But you can also roll if need to change your yaw and roll 90 degrees, it would be pitch.

- Well, the control authority you need is much more in pitch than any of the other axes. Like, the amount of control authority you need for roll is practically nothing. - [Tim] Right. - But for pitch, you've got to basically push the booster down. So, you got to push this monster thing into the wind and it doesn't want to go there.

The amount of pitch force you need, that's where you need the most amount of force. So, having the two pairs of fins closer together, like more like an X-wing fighter allows them to contribute more in pitch. - [Tim] Which then allows more glide or more of the air frame hitting the sides of the booster. - You care about how much force do you have relative to how much force do you need in a given axis? So you need a lot of force in the pitch axis, so that's where you want to bias your grip fins.

- [Tim] Yep, yep. - You could arguably say they should be biased even closer together than they are currently. - [Tim] Yeah.

- But this is a reasonable guess. - [Tim] In between. - Yeah. - [Tim] So, this might end up pitching over more than the Falcon 9. 'Cause 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 by gliding. - It's actually, you've got various things that are better, some things that are better, some things that are worse.

You can leave 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 see-saw. You got a see-saw or a wrench. And if you have a long wrench, it's easier to turn than a short wrench.

If you have a shorter booster, a short booster is harder to turn than a longer booster. Depending on where the control surface is relative to your center of mass. The center mass is kind of where the see-saw, like it's seesawing around that center mass and center of pressure.

You have two things basically. It's like basically, it sounds more complicated than it is. But basically it's a teeter-totter or a see-saw, where there's a center of pressure and a center of mass. And it's gonna basically just rotate around that. - [Tim] Yep, yep. - So, if you've got a long stage that where the grid fins are far away from your center of mass, then you need less force to turn it.

- [Tim] To turn it, yep. - Basically. - [Tim] Gotcha, gotcha. That makes sense.

- Yeah, like a really short stubby thing, it would actually be quite hard to move it. - [Tim] To move it. But at least as far as the fineness ratio, this has a lot more potential since it's wider, to actually use atmospheric, to use the atmosphere to slow down before it even has to light its engines. 'Cause you know how like New Glen has those straights on the side. And it looks like they're really planning to almost fly the thing for a little bit 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 guys have a pretty, compared to Falcon 9, there's a lot less fine ratio.

It seems like you get a lot more lift out of the thing. - Realistically, this is gonna come in at something close to terminal velocity. - [Tim] Right, oh yeah. - 'Cause you're trying to get to a precise point. So, it's very difficult to do a fast pitch up maneuver and also get caught by the tower.

- [Tim] Right. - If you've got a very big landing area, then you could do that maybe. If you want a precise landing, you can't do a sudden pitch up at the end. And then you've got pretty big moments of inertia here. Big things don't move like small things. - [Tim] Right.

- You don't see a super tanker dashing around like a speed boat. - [Tim] Right, right, right. - This is like, in rocket form of a super tanker. It doesn't move fast.

It's like (vocalizes). - [Tim] Yeah. - Like way bigger than a whale. - [Tim] Yeah, yes it is. - It's just not gonna move fast.

- [Tim] Right. - Although, ironically, liftoff will be weirdly fast. - [Tim] Yeah. - Big rotating things always move slower than small rotating things.

- [Tim] Yeah. - You know? - [Tim] Yeah. - Yeah. - [Tim] Should we head to the pad? - Yeah, there's a lot of potential improvements.

I mean. Yeah. - Man, oh man, wasn't that an awesome conversation? Now, in part three, we're gonna be taking you down to the launch pad, and you're gonna 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. 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 on over to www.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 at www.EverydayAstronaut.com/shop. Thanks, everybody. That's gonna do it for me. I'm Tim Dodd, the Everyday Astronaut, bringing space down to Earth for everyday people.

2021-08-11 20:08

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