Starbase Tour with Everyday Astronaut — Part 2
Questions on ElonsFAQ asked in this interview (2)
Transcript
0:00Tim DoddHi, 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.
0:13Tim DoddAnd 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.
0:29Tim DoddWe 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.
0:39Tim DoddThe link in the description is below for [email protected]. 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.
0:50Elon MuskYeah, just like, you know, it just can't be any. Any more than people are already getting from telephoto lenses.
0:58Tim DoddThat's which is pretty much.
1:00Elon MuskAnd frankly, if some fool wants to copy this design, go for. I mean, Raptor 2 is a giant improvement over this.
1:09Tim DoddSo what's like the big simplifications you're hoping to have?
1:15Elon MuskWell, maybe I shouldn't tell you all the secrets. We have, like funny things on the Pikachu over there.
1:25Tim DoddI love that.
1:26Elon MuskHello again.
1:27Tim DoddHello again.
1:27Elon MuskSo that probably.
1:28Tim DoddI assume that means it's flown. Is that a flown one?
1:32Elon MuskI don't know if this one's been flown.
1:36Tim DoddThis really does look like that thing with all the NK33s, you know, the videos.
1:40Elon MuskYeah, exactly. Like the engines discovered engines that came back from the coal.
1:43Tim DoddYes, it seriously literally looks like that. This is insane. And then, man, that rat rack is big. Jeez.
1:53Elon MuskI 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.
2:04Elon MuskYeah, 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.
2:17Tim DoddWell, it's already slimmed down a ton from like, you know, the.
2:20Elon MuskIt used to look like a freaking Christmas tree. Yeah, like you couldn't even see the engine for all the stuff that was ready.
2:25Tim DoddNo, 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.
2:32Tim DoddEvery 2 millimeters.
2:34Elon MuskYes.
2:35Tim DoddSo RapVac or RaptorVac has its own channel on the extension. It looks like.
2:42Elon MuskYeah, that's a steel tube wall. Braised steel tube wall.
2:47Tim DoddThat 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.
2:55Elon MuskThroat'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.
3:07Elon MuskYeah, yeah.
3:08Tim DoddWhat is expansion ratio again? Is it like 150 or.
3:13Elon MuskMan. I think we're. So this is actually there's. I think we're around 80ish.
3:20Tim DoddOh, okay.
3:22Elon MuskBut we want to get to. We want to do a little bit better. Maybe 90, so.
3:30Tim DoddBecause you're already getting like 380 ISP out of that thing, aren't you? I mean, sorry.
3:35Elon MuskYeah,383.80 is the aspirational number. Okay. But we should be. I think we think we'll get like 370. 378.
3:44Tim DoddOkay.
3:45Elon MuskSo.
3:45Tim DoddOkay, how are those coming along? It looks like obviously you've got a third one here. You've obviously made at least three.
3:53Elon MuskYeah.
3:55Tim DoddAnd obviously S20 is going to have three. Yes, yes.
4:02Elon MuskSo.
4:03Tim DoddGeez.
4:04Elon MuskBut 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.
4:22Elon MuskOkay. Okay, so that's.
4:25Tim DoddAnd that's going to be the difference between the R boost and the.
4:28Elon MuskYeah, I mean, it's basically the same engine minus pvc.
4:33Tim DoddGotcha. So the outer shells that you're working on for The GSE are 1212 meters.
4:40Elon MuskThere's a Raptor without the stuff. Looks practically naked.
4:44Tim DoddYou're like, actually that's secretly version two. It's super simple.
4:47Elon MuskNo, version two will look a bit like that actually.
4:49Tim DoddReally?
4:49Elon MuskIt's very tight.
4:50Tim DoddReally? 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.
4:59Tim DoddWith electronics though, either.
5:00Elon MuskYou know, they simply did. Back in those days they did not have good electronics.
5:05Tim DoddRight.
5:05Elon MuskSo there's nothing to.
5:06Tim DoddThere's nothing to wire.
5:07Elon MuskYeah, yeah.
5:10Tim DoddIs 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?
5:20Tim DoddAnd 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.
5:28Tim DoddYou weren't trying to like do a mission. You're just trying to get data out of the thing. Yeah.
5:35Elon MuskWe 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.
5:50Elon MuskThere 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.
6:05Elon MuskFalcon 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.
6:19Elon MuskWe'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.
6:38Tim DoddIt's a big deal.
6:38Elon MuskYeah. That's the fundamental holy grail for making life multi planetary.
6:48Tim DoddWhere do you think the space shuttle failed in being in any. Definitely. Rapidly would be a word you got to scratch off the list.
6:56Elon MuskAnd refurbishable might be a better word.
6:58Tim DoddBut 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?
7:05Elon MuskSpace 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.
7:16Tim DoddWell, they did very, very little. I mean.
7:18Elon MuskYeah, 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.
7:27Tim DoddBecause the design froze.
7:29Elon MuskYeah. 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.
7:45Elon MuskSmall reward. So the issues with the O ring and then with the insulation coming off and hitting the wing.
7:58Tim DoddYeah.
7:58Elon MuskWhere they'd seen this before.
8:00Tim DoddYeah.
8:00Elon MuskThey 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.
8:15Tim DoddRight.
8:16Elon MuskSo 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.
8:27Elon MuskSo 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.
8:37Tim DoddDo 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.
8:49Tim DoddOr what's your.
8:50Elon MuskYeah, 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.
9:04Elon MuskBasically 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.
9:22Elon MuskAnd 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
9:36Tim Doddjettisoned.
9:37Elon MuskIt has to be jettisoned on every mission. So if it's not jettisoned, the crew dies.
9:40Tim DoddThat's a failure mode right there.
9:42Elon MuskThat'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.
9:51Elon MuskSo 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.
10:08Elon MuskSo 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.
10:17Tim DoddRight.
10:18Elon MuskAnd then there's, you can't have an escape system on the moon or on Mars.
10:22Tim DoddOr on Mars.
10:22Elon MuskYeah, 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.
10:34Tim DoddRight.
10:35Elon MuskSo 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.
10:45Tim DoddRight, Right.
10:46Elon MuskSo kind of pointless to do it on Earth. Well, it just fly it a lot.
10:50Tim DoddRight. 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.
11:08Tim DoddSo let's see what. What is. Oh, that's all. Those are the vacuum mounts, aren't they?
11:17Elon MuskYeah.
11:18Tim DoddWow, that's cool.
11:20Elon MuskYeah, 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.
11:31Tim DoddWell, 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.
11:39Tim DoddAnd 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.
11:50Tim DoddYou have to force yourself to start.
11:53Elon MuskYeah.
11:53Tim DoddAnd then. Yeah, that's. That you improve from there.
11:59Elon MuskExactly.
12:09Tim DoddMan, are you pretty used to the heat. I feel like it's. It's pretty hot out here.
12:16Elon MuskIt is hot. I mean, this is the worst. This is like summer, you know, so.
12:21Tim DoddRight.
12:21Elon MuskThat's just like the worst of it.
12:23Tim DoddYeah.
12:23Elon MuskIt'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.
12:31Tim DoddOh, 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.
12:42Tim DoddHow are you feeling about the thermal protection system? You feel like that's a pretty good solution?
12:47Elon MuskWe'll find out.
12:49Tim DoddThey'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.
12:56Elon MuskIt hasn't full. I mean, it's still there. I mean, you can see the videos.
13:00Tim DoddYeah.
13:01Elon MuskIt 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.
13:17Elon MuskIt'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.
13:35Elon MuskSo 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.
13:54Elon MuskThen 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.
14:05Elon MuskSo 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.
14:16Elon MuskThe 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.
14:34Elon MuskSo 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.
14:45Elon MuskIt'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.
14:56Tim DoddYeah, yeah.
14:57Elon MuskSo hopefully we at least find out where the crack in the armor is. That would be great.
15:02Tim DoddAnd then if you have to, you can make some thicker or smaller iterate to that degree of where you find those failures again.
15:08Elon MuskYes.
15:10Tim DoddHow 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.
15:17Tim DoddIt's just a million pieces at the bottom of the ocean. How will you know where it failed?
15:26Elon MuskI mean we have temperature sensors.
15:37Elon MuskYou probably need like some thermal images inside the tanks. So just like IR camera so you
15:44Tim Doddcan see if certain specs is getting real hot.
15:47Elon MuskYeah. IR cameras on the inside will show you what the backside temperature is.
15:50Tim DoddYeah, yeah. Let you know if a leak something
15:52Elon Muskgonna pop if the backside temperature like it was. Frankly I'm not sure. I take it back. If you just have a camera. Camera.
15:57Tim DoddYeah. You'll know.
15:58Elon MuskVisual. 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.
16:09Tim DoddRight, right.
16:10Elon MuskSo you'll know you'll know. It's so subtle.
16:20Tim DoddAnd 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.
16:36Elon MuskIt's getting to orbital velocity, but with a. With a. But it's. It's not circularizing. It's perigee.
16:44Tim DoddYes.
16:44Elon MuskSo 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.
16:52Tim DoddYep. And the velocity will probably be greater re. Entry velocity will be greater that way. Or similar.
16:57Elon MuskSimilar. 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.
17:11Elon MuskSo like, raising perigee slightly is easy? Yeah, yeah. It's like remarkably easy. So we just want to raise it like a little bit.
17:20Tim DoddAre you hoping to actually recover the first one or like, try to even land or any. I mean, is it going to.
17:25Elon MuskFirst 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.
17:42Elon MuskYeah, 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.
17:54Elon MuskPlease do not blow up on the stand. That's my one concern.
17:57Tim DoddBut you keep calling, you, calling the stand Stage zero, the launch system. Really? Yeah, the ground, gse, the tower and all that stuff.
18:08Elon MuskZero. Yeah. Okay.
18:09Tim DoddYeah, 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.
18:17Elon MuskReally?
18:17Tim DoddFour is one.
18:18Elon MuskOkay.
18:18Tim DoddAnd then what I would call the.
18:19Elon MuskWait, what?
18:20Tim DoddNo, 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.
18:28Tim DoddAnd I kept being like, oh, yeah, third, you know, second stage. And they're like, no, no, that's third stage, you know.
18:34Elon MuskSo 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.
18:56Elon MuskThat'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.
19:05Elon MuskYes, that would be great. And then the best case outcome for the first flight would be that
19:15Tim Doddthe
19:15Elon Muskbooster does its job and also is able to relight the engines and it's going to splash down in the Gulf.
19:23Tim DoddOnly like 20 miles out or something. Something. Right, yeah.
19:25Elon MuskNot 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.
19:42Tim DoddYep, 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?
19:54Tim DoddWell, it won't even do a, you will do a boost back burn though on the first one too, right?
20:00Elon MuskLet'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.
20:08Tim DoddYeah.
20:10Elon MuskSo 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.
20:23Elon MuskSo it doesn't take out stage zero.
20:24Tim DoddRight, Yep. Yeah.
20:26Elon MuskSo 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?
20:39Tim DoddYes.
20:40Elon MuskMechazilla.
20:41Tim DoddYeah, Mechazilla.
20:42Elon MuskMegazilla.
20:43Tim DoddMechazilla. Mecha Mechazilla.
20:45Elon MuskOkay. Yeah. Like a giant Mechazilla. Yeah.
20:47Tim DoddAnd 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,
20:54Elon Muskthose, those little, the little tiny arms.
20:56Tim DoddThat tiny little T. Rex arm is going to hold the.
20:58Elon MuskYes, there's two of them. But those, those things can take a
21:02Tim Doddlot of load and then it's just literally like a flat, like a flat arm kind of like this, that.
21:07Elon MuskI 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.
21:17Elon MuskSo it's not exactly going to be top secret.
21:19Tim DoddRight, right.
21:21Elon MuskThis 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.
21:31Tim DoddThat 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.
21:42Tim DoddLike 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?
21:51Tim DoddBut now we're also seeing it all, so it's hard to compare.
21:54Elon MuskWell, I mean this is definitely a case where we are washing our laundry in public.
21:58Tim DoddYeah, yeah.
21:59Elon MuskAnd 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?
22:07Tim DoddRight?
22:09Elon MuskYeah, 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.
22:34Elon MuskIt'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.
22:49Elon MuskBut 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.
22:58Elon MuskSo 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.
23:12Elon MuskYou 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.
23:32Elon MuskYes. And the structure now has more load. So because it's carrying that extra ton of heat shield.
23:37Tim DoddYes.
23:38Elon MuskSo 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.
23:56Tim DoddDefinitely.
23:58Elon MuskSo 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.
24:11Elon MuskYeah.
24:13Tim DoddSo 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.
24:23Elon MuskI actually don't know the exact mass of 20. We'll know it when we weigh it.
24:28Tim DoddYeah,
24:35Elon MuskThere'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.
24:50Tim DoddReally?
24:51Elon MuskSo. Yes, but then you say like dry. Do you mean not counting the air inside it,
24:57Tim Doddby the way? The air.
24:58Elon MuskActually air mass is non trivial.
25:00Tim DoddNo, it's not.
25:01Elon MuskThis 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?
25:13Elon MuskLike 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.
25:19Elon MuskThat's a big change.
25:21Tim DoddOr with or without gimbal is something else that I've heard people kind of debate.
25:25Elon MuskYeah. 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.
25:40Elon MuskIt's like A plus for GG cycle architecture. But GG cycle architecture is not an A plus architecture.
25:46Tim DoddRight.
25:48Elon MuskFull 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.
26:00Elon MuskYeah, that's kind of how the, you know, things work here.
26:04Tim DoddSo what would you say version two is going to kind of come in at if you were to rate on.
26:08Elon MuskI don't know, I'd say it's like B plus. Okay. Something like that.
26:13Tim DoddSo good enough for now. But of course, yeah.
26:15Elon MuskRaptor 3, Raptor 4, Raptor 5. You know by Raptor 5 it'll be an A plus.
26:20Tim DoddYeah.
26:20Elon MuskSo yeah.
26:23Tim DoddShould 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.
26:31Elon MuskThis is. This is a new and improved nose cone.
26:36Tim DoddOh yeah. It's just straight. There's no cross section.
26:39Elon MuskSo 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.
26:51Elon MuskThis is, this is, this, this will be made of two rows of stretch formed.
26:55Tim DoddWow.
26:56Elon MuskSo and you can see it's like it's just way smoother.
26:58Tim DoddYeah.
27:00Elon MuskThis 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.
27:09Tim DoddRight, right, right.
27:11Elon MuskAnd then you can, you can have like things that are way bigger. Like you can't put this in a stamping press.
27:15Tim DoddRight.
27:15Elon MuskThis 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.
27:26Tim DoddRight.
27:27Elon MuskBut 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.
27:45Elon MuskSo you can just stretch form it over a big mandrel.
27:48Tim DoddAnd 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?
27:58Elon MuskYeah, I actually stopped work on the, on the door, the fairing door.
28:01Tim DoddOkay.
28:01Elon MuskYeah, we're going to focus on getting to of it. Yep. We don't need a door.
28:04Tim DoddYep, yep.
28:05Elon MuskSo 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.
28:13Elon MuskOkay. 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?
28:28Elon MuskWe 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.
28:44Elon MuskBut 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.
28:56Elon MuskBecause 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.
29:02Tim DoddWow.
29:04Elon MuskSo the reality is the early ones are gonna be amazing lone ornaments.
29:11Tim DoddYeah.
29:12Elon MuskI mean, as good as lone ornament gets, but they will not be
29:17Tim Doddnearly
29:18Elon Muskas good as the ones that follow. So then why keep them flying?
29:21Tim DoddThey'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.
29:26Elon MuskThey're just gonna retire the early ones anyway, so.
29:27Tim DoddYeah.
29:28Elon MuskWhy have a door on a thing that. Then we're gonna fly satellites anyway. Yeah.
29:33Tim DoddHow. 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.
29:41Elon MuskNo, 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.
29:53Elon MuskGoing to Mars, you need orbital refilling. Delivering satellites to Earth orbits, you do not need orbital refilling.
29:59Tim DoddRight. Right.
30:00Elon MuskSo let's punt that to later.
30:02Tim DoddOkay.
30:03Elon MuskI'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
30:16Tim Doddthe side, not up through the booster
30:18Elon Muskanymore 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.
30:25Elon MuskIt's better to move mast to the ground side.
30:27Tim DoddRight.
30:27Elon MuskThat's why we took the legs off the booster and just have the tower catch it.
30:32Tim DoddAre you thinking about doing a tower catch it?
30:34Elon MuskWhich 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.
30:48Elon MuskAnd 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.
31:02Elon MuskIt's very windy around here.
31:03Tim DoddYeah, it is.
31:05Elon MuskSo 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.
31:15Elon MuskSo 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.
31:28Elon MuskOkay.
31:29Tim DoddSo the Mechazilla arms are the ones that are going to be picking up the ship, not the crane.
31:35Elon MuskOkay. So.
31:41Elon MuskIt'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.
31:49Tim DoddWe've seen that a few times.
31:51Elon MuskYes. It could be that we were actually just literally mistaken, a miscommunication,
31:57Tim Doddany one
31:58Elon Muskof 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.
32:06Elon MuskYeah, 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.
32:23Elon MuskSo 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.
32:39Elon MuskWe'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.
32:49Elon MuskAnd then from the first stacking, then we can figure out.
32:56Elon MuskJust 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.
33:06Elon MuskIt's got, it's got like basically 20 mount points.
33:09Tim DoddRight.
33:11Elon MuskAnd 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.
33:20Elon MuskWe gotta adjust it.
33:21Tim DoddYeah.
33:21Elon MuskOkay. That, that, that launch ring is 370 tons. So. And it's gonna tweak. Like you move it from one place to another. Tweaks.
33:30Tim DoddYeah.
33:30Elon MuskYou 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.
33:42Elon MuskSo 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.
33:58Tim DoddIt's gonna be, that's gonna be insane to see.
34:01Elon MuskYeah, we're gonna try to put the ring on the stand, the launch ring on the stand tomorrow.
34:10Tim DoddWow.
34:12Elon MuskBut 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.
34:26Tim DoddOkay. Second flight, we'll use. Oh, so the first flight might still use the suborbital pad.
34:31Elon MuskNo, it's going to use the. It has to use the orbital pad. We can't.
34:34Tim DoddThe orbital.
34:35Elon MuskThe 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.
34:42Elon MuskIt's too low and too weak.
34:44Tim DoddYeah.
34:44Elon MuskOkay, so we got to launch it from the super beefy stand.
34:52Tim DoddYeah.
34:54Elon MuskBut we don't want to wait until everything's ready with the tower just to stack.
34:57Tim DoddOkay, 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
35:09Elon Muskwe do need the, The QD arm to work.
35:12Tim DoddOh, right. So that can be a stability thing.
35:15Elon MuskYeah, 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.
35:23Tim DoddOkay, so that has to be complete. Yes, but not necessarily the arms and everything else going on at that point.
35:29Elon MuskYeah,
35:32Tim Doddso at this point. At this point, I mean, we're.
35:35Elon MuskLike 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.
35:46Elon MuskOkay. Yeah.
35:49Tim DoddSo 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.
36:02Tim DoddI can't sleep because I'm not feeling. We're not. We haven't figured this out yet.
36:16Elon MuskI'm sorry.
36:16Tim DoddYeah. 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?
36:26Elon MuskI mean, it's a long list. So
36:31Tim Doddwhat's at the top of that right now, for you, at least personally?
36:43Elon MuskWell, 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.
36:57Elon MuskI mean, if I wasn't optimistic, I wouldn't be doing, you know, the crazy Things that I'm doing.
37:02Tim DoddRight.
37:02Elon MuskSo I must have like, I don't know, just pathologically optimistic, I suppose.
37:09Tim DoddWow.
37:09Elon MuskThat actually.
37:10Tim DoddLook at that.
37:10Elon MuskThat's. Yeah. It looks like dragon scales.
37:12Tim DoddIt is incredible.
37:13Elon MuskThat looks cool.
37:14Tim DoddIt's actually like coming together a lot.
37:16Elon MuskIt totally looks like dragon scales.
37:18Tim DoddIt really does.
37:19Elon MuskYeah.
37:20Tim DoddAnd it's. It's so much tidier and cleaner looking than I thought.
37:24Elon MuskYeah. I mean there's a few broken tiles, but overall it looks cool.
37:27Tim DoddThat's incredible.
37:30Elon MuskWow.
37:31Tim DoddSo 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.
37:41Tim DoddSo I guess you don't really have to cool the inside of the like the flap joint itself because it's kind of already.
37:47Elon MuskNo, 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.
38:00Elon MuskSo sometimes I'll say something that's wrong, but I'll. You know,
38:09Tim Doddthe.
38:11Elon MuskI think we have a design error with,
38:17Elon MuskWith 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.
38:36Elon MuskSo 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.
38:44Elon MuskYep. 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.
38:57Elon MuskYou're applying a trajectory that minimizes peak heat. But you don't care about total heat load. You just care about minimizing your peak
39:06Tim Doddheat because you have a, A good insulator here. Not, you know, you're not blading.
39:10Elon MuskYes, 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.
39:21Tim DoddYeah.
39:21Elon MuskBecause it's got so much margin. Yeah. But apica is, is literally means phenolic impregnated carbon ablator.
39:27Tim DoddYep.
39:28Elon MuskSo 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?
39:43Elon MuskWhen 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.
39:56Elon MuskAnd 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.
40:09Tim DoddReally?
40:09Elon MuskYeah, 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.
40:23Elon MuskThat'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.
40:36Tim DoddWow. Yeah. Interesting constraint at the end of it
40:41Elon Muskall, you know, so if you just have a lot of heat, suddenly that's actually better for Dragon. Like high peak, low, total heating.
40:48Tim DoddYep, yep. And so it's re. Entry point profile is totally different too. You can come in steeper as opposed to coming.
40:53Elon MuskDragon 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.
41:03Elon MuskIf 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.
41:17Elon MuskAnd 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?
41:24Tim DoddRight?
41:24Elon MuskAnd 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?
41:37Elon MuskAnyway, 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.
41:49Elon MuskAnd 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?
42:07Elon MuskBut 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.
42:18Elon MuskAnd then your lateral point is pretty easy to tune because you just, you have a lift vector going left and right.
42:22Tim DoddIt'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.
42:34Tim DoddPretty much. More or less.
42:35Elon MuskYeah.
42:35Tim DoddI mean, it.
42:38Elon MuskI think it's just very important for people to appreciate that there's a very gigantic difference between orbit and space.
42:45Tim DoddRight.
42:46Elon MuskIt is, it is actually relatively easy to get to space, but it is very hard to get to orbit.
42:53Tim DoddRight.
42:53Elon MuskAnd 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.
43:08Tim DoddRight.
43:08Elon MuskSo, 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.
43:22Tim DoddYeah.
43:22Elon MuskHe went to the border of space twice and didn't even need, didn't even scorch the paint.
43:30Tim DoddRight.
43:30Elon MuskSo that's like, it's really not very hot if you don't even burn the paint.
43:35Tim DoddRight. That's true. Yeah, that's true.
43:40Elon MuskWhereas this needs like really intense heat shielding or it's gonna get, you know, blow up, basically.
43:46Tim DoddYeah, 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.
43:55Elon MuskYeah, I mean, just don't let anything drop in your head.
43:57Tim DoddAll right, deal. So there's another barrel section of S20.
44:06Elon MuskI mean, it looks a little garage shop, to be frank, but it's, it's like weirdly like super advanced technology with garage shop.
44:15Tim DoddWell, it is very unique of you guys to basically build the rockets first and then start building a factory around
44:21Elon Muskit, you know, because the production system is the actual hard thing.
44:25Tim DoddRight.
44:26Elon MuskThe 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.
44:43Elon MuskIt's next to a run Johns, literally.
44:47Tim DoddWhat'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.
44:57Elon MuskYeah, 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.
45:12Elon MuskAnd 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.
45:20Tim DoddSo next to Ron John's. I didn't.
45:23Elon MuskWell, technically it's next to Ron John's distribution warehouse.
45:26Tim DoddOkay.
45:27Elon MuskLiterally, 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.
45:40Elon MuskIt's not tiny because there's a lot of. You need to make a lot of these tiles.
45:46Tim DoddAnd 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
45:56Elon Muskyou can see, we're figuring it out.
45:58Tim DoddI'm surprised though. Even as the. As the area tapers, it's not, I
46:03Elon Muskwould say, Mara's head of heat shield engineering. It's like, I'm gonna text him like, yo, man, what's going on?
46:15Tim DoddIt doesn't seem like there's a ton of unique. They mostly look uniform, which obviously will help with.
46:21Elon MuskYeah, they're not all uniform, but a
46:25Tim Doddlot more than the shuttle. What's your expected? What are you hoping to get for reuse out of these things?
46:39Elon MuskOh, I mean, no meaningful limit. As many as you want.
47:19Tim DoddThere we go. We got right back into cameraception for you there for a second. Camera inside a camera.
47:36Elon MuskYeah, 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.
47:52Elon MuskThe 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.
48:08Elon MuskSo 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?
48:21Elon MuskIt'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.
48:35Elon MuskSo 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.
48:44Elon MuskSo you can't use rubber.
48:45Tim DoddRight.
48:46Elon MuskSo it's going to be a metal seal and with a torturous path.
48:51Tim DoddHave you thought about. Back in the day, you talked about transpirational cooling.
48:54Elon MuskYes. So that's one of the things you could throw at it is transpiration cooler joint.
48:58Tim DoddThat would be. So I just want to see it bleeding. Methane, honestly. And just.
49:02Elon MuskIt'll definitely help.
49:03Tim DoddYeah. 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.
49:21Elon MuskIt'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.
49:42Elon MuskAir 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.
49:51Elon MuskSo. 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.
50:04Tim DoddRight, Right. Because it's already detached.
50:05Elon MuskIt's not as hot as the plasma that's hitting it.
50:07Tim DoddRight.
50:08Elon MuskSo. Yeah.
50:11Tim DoddWow.
50:12Elon MuskAll right, well, let's see. I guess the car is. Okay,
50:28Tim DoddSo 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.
50:44Elon MuskYeah, like I said, it's. It is a constantly evolving thing. So.
50:49Tim DoddRight.
50:50Elon MuskWe'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.
51:02Tim DoddYou're working on a new high bay, too, right?
51:05Elon MuskYeah, we're building a higher high bay.
51:07Tim DoddUber high.
51:09Elon MuskIt'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.
51:18Tim DoddOkay.
51:19Elon MuskSo, 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.
51:27Tim DoddAbout how tall?
51:33Elon MuskI don't know. Probably. Oh, it's like 100 meters.
51:35Tim DoddOkay. And this one's.
51:37Elon MuskThe one's
51:39Tim Doddlike 80?
51:40Elon MuskYeah, 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.
51:55Tim DoddYou did that on purpose?
51:57Elon MuskNo, 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.
52:05Elon MuskSo 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.
52:13Tim DoddRight.
52:13Elon MuskSo 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.
52:32Elon MuskAnd this is all happenstance.
52:34Tim DoddRight, Right. I love that.
52:37Elon MuskWhat the hell's going on?
52:41Tim DoddWell. 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.
52:56Tim DoddIt was like what? Something ridiculous. Yes. It was like the weirdest.
53:00Elon MuskNo, I was born 69 days after 4:20, by the way. Oh, yeah. Come on. Come on.
53:07Tim DoddThis is ridiculous.
53:08Elon MuskIt's ridiculous.
53:09Tim DoddThat's so funny.
53:10Elon MuskI mean, what the hell?
53:14Tim DoddOh, man. This is insane.
53:20Elon MuskIt's like. Am I an avatar in someone's video game? Yes. Oh, really?
53:25Tim DoddStatistically, yeah.
53:26Elon MuskOkay.
53:28Tim DoddYou're probably doing pretty good at the game though. I bet you're like the top ranked player.
53:31Elon MuskOkay, well, that's something.
53:35Tim DoddSo what, do you have a name for the High Bay Bar yet?
53:39Elon MuskNo, 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.
53:52Elon MuskAnd 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.
54:03Elon MuskThey're installing the grid fin.
54:05Tim DoddYeah. 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.
54:17Tim DoddIs 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.
54:26Tim DoddYou're likely not doing pitch and yaw when it's coming in for reentry.
54:31Elon MuskWell, actually, no. We're controlling on three axes. Now, technically you only need three fins to control on three axes, but you
54:43Tim Doddcan also roll if you need to change your yawn, roll 90 degrees to do pitch.
54:48Elon MuskWell, 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.
54:55Tim DoddRight.
54:57Elon MuskAnd. 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.
55:07Tim DoddYeah.
55:08Elon MuskSo 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.
55:18Tim DoddYep.
55:19Elon MuskAllows them to contribute more in pitch. Yep.
55:21Tim DoddWhich then allows more glide or more. More of the airframe hitting the sides of the booster.
55:27Elon MuskYou care about. Like, how much force do you have relative to how much force you need in a given axis?
55:32Tim DoddOkay.
55:33Elon MuskSo 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.
55:44Elon MuskYeah. But this is a reasonable guess in between. Yeah.
55:49Tim DoddWell, 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.
55:58Tim DoddSo maybe this could pitch even more and arrest more of its velocity. It's actually.
56:05Elon MuskYou'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.
56:17Elon MuskA 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.
56:26Elon MuskJust 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.
56:34Elon MuskSo 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.
56:48Elon MuskOkay. 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.
56:58Elon MuskBasically 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.
57:10Elon MuskAnd 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.
57:27Tim DoddTo turn it.
57:27Elon MuskYeah. So basically.
57:29Tim DoddGotcha. Gotcha. That makes sense.
57:31Elon MuskYeah. If you had like a really short stubby thing, it would actually be quite hard to move it.
57:35Tim DoddTo move it.
57:36Elon MuskYeah.
57:37Tim DoddBut 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.
57:48Tim DoddBecause 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.
58:04Tim DoddYou 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.
58:15Elon MuskRealistically, 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.
58:36Tim DoddRight.
58:37Elon MuskLike 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.
58:51Elon MuskBig things don't move like small things. Right. So like you don't see a supertanker dashing around like a speedboat.
58:56Tim DoddRight, Right.
58:57Elon MuskThis 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.
59:10Tim DoddYes, it is.
59:12Elon MuskSo 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.
59:33Tim DoddYeah.
59:33Elon MuskSo it's, it's. Yeah, like I said yeah, there's, there's a lot of potential improvements.
59:49Elon MuskI mean,
59:55Elon MuskYeah.
59:56Tim DoddMan, 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.
1:00:06Tim DoddIt'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.
1:00:15Tim DoddAgain. 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.
1:00:27Tim DoddIf 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.
1:00:52Tim DoddYou'll find lots of fun [email protected] 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.