- Hi, it's me, Tim Dodd,
the Everyday Astronaut. Welcome to STARBASE Texas. This is where SpaceX is building testing, and even launching their
mars bound rocket Star ship. Today, I'm gonna take you inside the gates and show you things that have never been
shared outside of SpaceX. First of all, we have the
ultimate tour guide, Elon Musk, who answers all of my questions and gives us unbelievable insights to the rockets development. We talked and walked
around for over two hours. So I'll be cutting this
up into three parts. The first two are at the Star Base factory and the last one is at the launch pad. Each section has a goldmine
of valuable information. So make sure you're subscribed. You've got your notifications on and you've got your note
pads ready to jot some notes. Now heads up, we talk about some
pretty advanced concepts and subject matter that
can be pretty intimidating on first listen, but don't
worry, I've got you covered with lots of informational
videos here on my channel. So perhaps if you are new to Star ship or really all of this stuff, consider watching my
complete guide to Star ship, that'll be a really good overview for you for some of the things that we talk about here in this conversation. And I'll also be linking to
some of my other videos that will help out with some of the stuff that we talk about as well. Now you might notice, we
mention Soviet rocket engines quite a bit in this conversation. Maybe it's because I was
wearing my new Soyuz shirt that you can get at
everydayastronaunt.com/shop, or perhaps it's because I've been working on a complete history and family tree of Soviet rocket engines
for almost two years now. And that video is currently in the works and it will be out when it's done. And one last thing, this video is broken up into
sections and we have links in the description for those sections. We also will occasionally
be putting up a little map, courtesy of ring Watchers on
Twitter that will help you keep your bearings as
we're walking around. I think that'll help quite a bit. And we also have an article version of kind of our conversation
and some of the key points that we bring up over at
everydayastronaut.com. There is a link in the
description to that as well. Okay, enough talking, let's
go hang out with Elon. - Is it the camera? Probably with the camera, and then somebody else for the camera. - [Tim] It's just camera envy at this point. He saw me with this and he's like listen- - I'll get my camera out. - [Tim] Yeah, you take a video of me. - So I can take a video of this, of you guys taking the video. - Make sure this is going through there. Just shoot the screen the whole time. I don't want anything else. - All right, so this is... Okay, so this is I'm being videoed here. And then the video of the video. This is the video on
the video of the video. - Go back there. (laughs) - So I feel like I got here maybe at about the most exciting peak of insanity. - It's definitely a very
exciting time, 'cause we are in kind of a final push
to complete the launch pad system, stage zero, essentially. So we're saying that the launch system, the tower and the, you know, the chopstick arms to catch the rocket are as complex as either of the stages. - [Tim] Really? - Yeah, absolutely, if not more. We could produce boosters and ships way easier than we could
make the launch site. So therefor I'll say it is
harder suddenly than any single booster or ship. - I think that's one of the
things people don't even realize is the manufacturing out here, that's kind of one of the
things that you harp on so much is how, you know, how that's so important and
that's in the long scheme, the hardest part of all of
this is just manufacturing. - I think, currently a
factory is underrated and design is overrated. So people generally think that, like this Eureka moment of
like you come up with this idea and that's it, now it's good. But the design like this, literally a thousand percent, maybe 10000% more work that
goes into the production system than the thing itself. So say like how much effort we
put into say designing Raptor versus deciding the manufacturing system it's 10 to a 100 times more effort to design the manufacturing
system than the engine. - [Tim] Even of a Raptor? - Oh yeah, absolutely. Especially with Raptor. Quote basically the amount
of effort that goes into the design rounds down to zero. - [Tim] Right, right. - Relative to the amount
of the effort that goes into the manufacturing system. And if this was not true, I'd like 1000 Raptors please. Oh, you can't make them? Oh, okay. - [Tim] Right, right. - So this is like just very fundamentally underappreciated. If people have not been in manufacturing, especially manufacturing of
something that's relatively new, then they don't understand. And they think the
design is the hard part, and they think production is like a copier or something like that. This is completely false. - [Tim] It's definitely not
as sexy as the end thing. Like, you know, the end product
is very sexy and you know, that's what draws people's attention, but the whole back end of it
is what makes it possible. - I can't emphasize enough, I'm trying to correct the misperception that design is the hard part. It is not the hard part. There have been lots of great
rocket engines designed. You've spend a lot of time looking at the Russian rocket engine designs. There's some amazing Russian
rocket engine designs. They've been doing stage
combustion for a long time. And they've done, I don't know, hundreds of different designs, literally. So the hard part is not, can you design a stage combustion engine? This has been done. Now admittedly, ours is a
higher pressure than before, and it is a full flow stage combustion, but that's a relatively minor increments relative to what the
Russians have already done. What is super hard about Raptor is, how do we make a Raptor where
the cost per ton of thrust is under a thousand dollars? Yeah, I mean, we
definitely don't wanna cut, the fundamental thing
that needs to be fixed is the cost per ton to orbit. So things that address the
cost per ton to orbit are good. If humanity will be a
multi-planet species, if we get cost per ton
to orbit to a point where we can afford to become
a space race civilization and a multiplanar species. - [Tim] Right. - So this is, at it's heart, it is a fundamentally an optimization of cost per ton to orbit
and then ultimately cost per ton to the surface of Mars. - [Tim] Right. - Well, if you're working
on getting the cost of, even when you're starting
to think of it as dollars, dollar per ton of thrust, I don't know if anyone's ever considered
that as a key metric. That's a new thing that
I've never thought about, never considered, well, not even... - [Tim] Raptor is kind of unique. And now you start also thinking about instead of thrust to weight ratio, when you have a fixed diameter
and fixed circle area, you're also worried about the
nozzle exit to thrust ratio as being a pretty strong
consideration too. - Yeah, you basically end
up pulling up all the area under the rocket. So for this version, we have 29 engines. There is a lot of beeping. I'm not sure having this many things beep is actually helpful. - [Tim] It's a sensory overload. - It's like everything
around you is crying Wolf. - If everything's in danger, nothing is danger - - And you're just got to turn it out. Yeah, exactly. So it's pretty silly, but- - [ Tim] So this is
obviously the nose of booster 4. - [Elon] This is
basically, that's the inter stage and the fuel tank of booster 4. - What are the little... So obviously that's where
the grid fins go, right? And then what's the thing in between them? - that's basically, that's
actually the Mount point. There are two. It's debatable whether this
is the right design or not. In fact, it's like the
whole design is wrong, just a matter of how wrong. But that's one of the load points for picking up the booster. It's just like tiny
little, it looks small, but it's actually not
that small, like close up it's this thing is just high in the air. Like all your sense of
perspective is wrong. And when this lands, it has like basically the
density of a beer can. An empty beer can. With like some mass, you know, with the engine is obviously- - [Tim] What is the dry mass, are you under 200 tonnes? - We should be under 200 tonnes. (machines beeping) The mass is a moving target. You often say like, what are propellant
residuals when you land? That's a big deal. Like both how much margin
on what you have and what are the unusable propellant. Like you can't just go
to zero margin, you know? Because you're the things going to like, crater. And it should be under 200 tonnes though. But as a rough rule of
thumb, like the engines, including mountain mass
are roughly two tonnes. So that's 29 engines at 58 tonnes. Then the sort of the fuel tank itself, and the oxygen tank, it's probably on the order of... Well, it's a little heavy right now. So maybe it's like 80 tonnes or so. Then you've got the inner stage, we've got the grid fins, batteries and a bunch of other things. So that's around 20 tonnes, and then you got propellant residuals, which might be on the
order of 20 tonnes too. All of that should come to, I don't know, call it 160 to 200 tonnes depending on the sort of final mass numbers. But like right now
everything is too heavy, like avionics too heavy. - [Tim] The avionics even? - Yeah. - [Tim] I thought it was just a little- - I mean, it should be, but the grid fins are electrically powered so we have batteries that
are energy optimized instead of power optimized. So like this grid fins
only let things work for like two or three minutes. So it's very different
from like an electric car, which you wanna have
several hours of driving. So it is really, we need
power optimized batteries, not energy optimized batteries. This is just a short term thing. So the battery mass can probably drop by maybe a factor of 10. So that's just one example. - [Tim] Should we back up a
little bit so there's little- - Yeah, less banging. - And then we're trying
to get that crane in here and do work. - [Tim] You got a lot of people on set right now. - Yeah, I mean, that residuals number is a super big deal on the mass though, because the booster is designed to have 3,600 tonnes of propelling, which is an almost 80%
liquid oxygen by mass, like 78%- - [Tim] 'Cause you burn at what? Is it 3,71- - 3.5, 3.7. - [Tim] Okay, yeah. - And you wanna bias in favor of oxygen because oxygen is dancer and cheaper. So in terms of improving
your payload and you know, reducing cost per ton, oxygen is basically plants make it
for free and plankton. So it's basically like electricity cost of separation and distillation. - [Tim] Right. Now, remind me though. Is it like, as far as the ratio goes, fuel OF ratio having a lighter molecule. Do we kind of want that
to be spewing out faster or something, 'cause it's less reaction. It can be accelerated quicker or faster. - Yeah, There's a trade off between... Well, I mean, would you
tend to get limited by is you don't wanna go too
close to stoichiometric 'cause the heats basically
melt your engine. So that tends to limit you on trying to go to higher OF, that's the actual thing limiting you. You tend to hit the
stoichiometric melting point before you rollover on ISP. - [Tim] Okay, okay. - Generally. - [Tim] That makes sense. - [Tim] And remind me of the grid fins. Do they still fold in? - No. - [Tim] No, is that gonna
be permanently that way? - Yeah. I have a rule just implement rigorously is the sort of five step process. First make your requirements less dumb, your requirements are definitely dumb. It does not matter who gave them to you. It's particularly dangerous, if a smart person gave
you the requirements, because you might not
question them enough. - [Tim] Yeah, you might
take it as like gospel. Like you have to do this. - Everyone's wrong, no matter who you are, everyone's wrong some of the time. So mega requirements is less dumb, then try very hard to
delete the part or process. This is actually very important. If you're not occasionally
adding things back in, you are not leading enough. The bias tends to be
very strongly towards, let's add this part of the
process step in case we need it. But you can basically
make in case arguments for so many things, and for a rocket that
is trying to achieve, try to be the first fully reusable rocket, there's never been a fully
reusable rocket people don't understand. Like this is like the holy
grail of rocketry, okay? And so you have to run
a tight margins because if you don't run tight margins, you're gonna get nothing to orbit. So you've got to delete
the part or process step, it's super important. And you can like hedge your bets. So that's why the grid fins for example, do not fold down because
that's a whole extra mechanism that we don't need. - [Tim] And they just compensated
for by having strong enough engine authority to steer
it in the little atmosphere. - Actually our simulation show, we don't really need any
extra engine authority. As long as the grid fins, you know, basically follow the flow, they're not really
disturbing the flow, it's really here nor there. As long as they don't have
a high angle of attack, it doesn't matter. - [Tim] A few degrees or something within a degree or two. - But in any case, it's the
thing we could add later. So now these grid fins are humongous. We will go see them. But they're like, I mean,
like a dinosaur bear trap. It's like you've build a
bear trap or a dinosaur, that's what these things look like. And if you have a whole
mechanism for folding them, that's like clearly a
part that we don't need. So this is a good design decision that actually I didn't come up with it, and it was like, great. But it followed the principle of like fleet partly lead the process. I was like, great, good
idea, let's not fold them. Why are we folding them, anyway? It's so random. Whatever requirement
or constraint you have, it must come with a
name, not a department. 'Cause you can't ask the departments, you have to ask a person, and that person who's putting forward, the requirement or
constraint must agree that they must take responsibility
for that requirement. Otherwise you could have a
requirement that basically an intern two years ago
randomly came up with, off the cuff and they're not
even have the company anymore. But it came from the, let's say, air loads department. They're like, actually
there's no one at our current department that currently agrees with that. This has by the way it
happened several times. - [Tim] So again, it could be literally thought of... - this could be,
it's every department. - [Tim] It can be thought
of as gospel again, but it might be something
that's just totally in passing. Or someone played too much Kerbel and had fins at the top of the rocket. And then it just, you know, it did this. - These things are often just
way more silly than you think. Anyway, so step one, make
your requirements less dumb. Step two, delete the part or process step. If you're not deleting
a part or process step, at least 10% of the time, basically if you're not
adding things back in 10% of the time, you're
clearly not deleting enough. And then only the third step
is simplify or optimize. The third step. The reason it's the third step
is 'cause it's very common, possibly the most common
error of a smart engineer is to optimize the thing
that should not exist. And say, well, why would you do that? Well, everyone has been trained in high school and college that you gotta answer the
question, convergent logic. So you can't tell a professor,
your question is dumb. You will get a bad grade. You have to ask the question. So everyone is basically,
without knowing it, they got like mental straight jacket on that is they'll work
on optimizing the thing that should simply not exist. I'll give you an example
for way back in the day of Falcon 1. So in the original sort
of like when Tom Mueller and I were like batting around, like, okay, what should this rocket look like? I think I was literally in like
Tom's kitchen or something. And we had like the
spreadsheet and like, okay, we need to like make
minimally viable rockets, like with half a tonne or
whatever something like that. And then initially the spreadsheet had, we had an NOT / MMH upper
stage, so sort of hypergol, upper stage kind of like a
varient of the TRW LMD. - [Tim] Which I think
Tom worked on, right? - Well, we trained Tom worked
on it, he's not that old. It was like a baby, you know, (laughs). A very advanced baby. But his mentors did work on the LMD. So, you know, lunar module descent engine. Basically a pintel injector- - [Tim] That's right, 'cause that's where the
pintel injector comes from. - You can also deep it and everything. Now the problem with that is, how much this NTO/MMH costs. It's super expensive, okay. It's like a rare chemical. So even if you're like, you know, if Edison and Tesla had a baby and that baby was smarter
than both of them combined and said, your job is to
optimize an NTO/MMH Upper stage, you're screwed, okay? So like nitrogen tetroxide
or monomethyl hydrazine are super expensive
and they're also toxic. - [Tim] They're super nasty, yeah. It's the handling costs
alone are pretty appreciable. - I mean, I do think like
saving safety is over-corrected on the NTO/MMH. It went from like, nobody had any protection
and breathe the fumes all day to it's cyanide. And neither of those are
true, it's not cyanide. You won't die. Bill Gerstenmaier told
me like this story of like, when he started at NASA,
they actually, I think passed around like a cup of like hydrazine so that everyone knew
what hydrazine smell. - [Tim] Nooo.... So like, 'cause it has like
a lot more rotten egg smell or something like that. So he literally opened a
cup of hydrazine and like, obviously he's still alive. So that's an example of like, don't optimize this thing
that shouldn't exist. We should not have NTO/MMH upper stage. Now Dragon does have that, but that's because Dragon's
got to do a lot of like nuanced firings of the Draco engines, you know, with very short pulse durations. And trying to have something
that's not hypergolic is very difficult and
it can be done, like, not hypergolic and not cryogenic. Now you options tend to suck. So, you know, they start
going down the peroxide barking up peroxide tree
or something like that. Or super esoteric mono props. And that's like the
again back to big money. - [Tim] That's step three. - Yeah, so exactly. Thanks to these quite laborious, sorry for the laborious explanation here, and then finally you get to step four, which is accelerate cycle time. You're moving too slowly, go faster, but don't go faster until you've worked on the
other three things first. If you're digging and you're great, don't dig it faster,
stop digging your grave. But you can always make me go faster. And then the final step is automate. And now I have personally made the mistake of going backwards on all
five steps multiple times. So I have to repeat this. - [Tim] Well on Model 3 Yes, multiple times, but on Model 3. Where literally I automated, accelerated, simplified and then deleted. But like one example
I've talked about before, is like the, they were
these like fiberglass mats, on top of the bottle three battery pack, they were in between the
full pan and the battery. And it was one point
Chuck in the battery pack production line and I was like, basically living on the battery
factory production line, like probably fixed the line. 'Cause it was like choking the entire Model 3 production program. So the first mistake was
we should not have... I like try to fix the automation, like make the robot better, make it like move faster, shorter
path, increase the torque, delete the reverse 720
degrees on the bolt. 'Cause that's unnecessary. Just go forward fast on a
20% rate at a 100% rate. And instead of spackeling glue
on the entire battery pack, just put little dabs of glue
because the fiberglass mask was sandwiched between the battery pack and the floor plan anyway. So all you need is like
somebody to hold it in place until put the backpack into the car. So automating was a mistake. Then accelerating was mistake. Then optimizing was a mistake. And finally I said, what
the hell are these mats for? And I asked the, the battery safety team, 'cause I was like, what
are these mats for? I said are they for fire
protection or something? They said, "No, they are
for noise and vibration. "So you don't get that." And I said, "But you're
the battery department." And I asked a NVA noise
vibration analysis team, what's it for, they said fire safety. So literally it was like
being in a Goldberg cartoon. It was like actually, I feel like I'm in a Goldberg cartoon quite frequently. So I'm like, you know, are we in like some simulation where I'm like trapped in some like
Kafka esq. / Goldberg cartoon situation, but that's
what it feels like a lot. So then finally, okay, great. Let's try a car with the
fiberglass mats and without, and they put a microphone in both, and see if you could tell the difference. You can not. In fact, I was like, which one is which? So we just deleted them and
just bypass this $2 million robot cell as a complete pile of none sense. Another mistake that has
to happen in production is too much in-process testing. So when you were first
setting up a production line, you don't know where things are breaking. You don't know where things are breaking, so you'll test like working
process at various steps and 'cause you wanna isolate
where's the mistake occurring? So a very common issue
with production lines is to not remove the end process testing after you diagnose where the problems are. So basically if you have
like a very high acceptance, like if things are getting
to end of line testing and are passing, then you don't need to
do in-process testing. But what used to happened
is they'll be like an initial development
engineering team that will be like basically debugging the production line, but then they will forget to take out the in-process testing steps. So then what happens is
the in-process tester will often choke the cycle time. Choke took the line production time. It'll be like the limiter
and also have some number of false positives and false negatives. But they'll be like false positive, like then you're like
rejecting good parts. So really in volume production,
if things are working well, you're really just taking a risk, will this subsystem be rejected in the training production
process or at the end. And so you just really wanna
move things pretty much, almost always to just test at
the end line, and that's it. Maybe there's like one
or two in-process steps that are hard to test an end of line, but basically remove almost everything. And there is another thing
with battery pack where, this is so crazy. Like one of the things the
battery pack has to do is to resist water ingress,
so it has to be leak proof. So if you drive through deep water, water doesn't come into the battery pack you're short of battery back. You might have seen some
of the videos of like people driving Teslas in like
extremely flooded waters, where it's like half underwater. Yeah, like there was literally a guy, I believe in Kazakhstan
literally drove a model S through a submerged water tunnel. All the other cars were out and he basically steered
the car with the wheels and use the wheel rotation, like a boat and drove out the tunnel. So it's important to have the battery pack resists water ingress. But then instead of us doing a pressure test on the battery pack, we were actually pressurizing
the inside of the battery pack which was the wrong direction. And the battery pack lid was glued. But, you know, we basically
had resin that was not cured. And so we were just
blurting out the resin, which doesn't a dumb sense. 'Cause you should actually
be drawing your vacuum on the front of pack
and not pressurizing it. And especially not
pressurizing it when there's uncured resin is what's
holding down the battery pack. So the pack was failing quite often on the pressurization tests, which should have been a vacuum test. - [Tim] Oh, speaking of grid fins. - Yeah, great. - [Tim] Look at that. Man, that thing is huge. - Yeah, that's right so it's like a- - [Tim] Dinosaur bear trap? - Dinosaur bear trap. - [Tim] Oh, wait, that'd just
a dinosaur trap wouldn't it? - This is a dinosaur trap. - [Tim] That's insane, honestly. - This thing could catch a T-Rex. (laughs) - [Tim] Oh my gosh, that's crazy. And of course it's got the serrated teeth, which helping the
transonic regimes, right? - Yeah. - [Tim] Is there any
other reason for the teeth other than that? - No it's just, well, it actually helps in
transonic and subsonic, but the effectiveness is
better if you've got a pointy , if it's more pointy basically. There is a lot of pointy-ness, Sorry, hey Marvin. So he just gets crushed under a... - [Tim] Wow, so how
heavy are these guys? - These are, I like... actually I don't know the number off hand, but probably at least
three tonnes, I'm guessing. When I say it's like a moving target, this is not the, like I
wouldn't take this to the bank. Like it's not, you know... There's quite a lot of mass
we can get out of this. - [Tim] It's just good enough for now. Like that's- - Yeah, it's good enough now. But like, you know, we're basically just needs to be like enough control authority to get
this through the atmosphere and positioned well enough so
that when the engines light, the engine can correct
whatever error is left after that we couldn't take
out what the grid fins. - [Tim] Man, that is crazy. Those are huge. It looks like the motor will mount to the lever arm there, is that just... - So this is, yeah... This will react to onto the
dome, basically a fuel dome. So there's like kind of
like a C channel around the fuel dome at the top. And there's a motor that's
gonna rotate this with a gearbox and that's basically the load
will agree reacted between the circular feature that you see there. And the sort of, I
shouldn't say C channel, sort of a L channel on the dome. So it's just a simple
sort of ring on the dome. - [Tim] And then is that
so, what I'm seeing there, where there's the rope is actually a through on the end here, is that the lever arm for the thing? Or is that just... - Yeah. - [Tim] ahh I see is
slides over, it's like... - Yeah. - [Tim] Okay. - That's where the motor
will interact, so yeah. - [Tim] Wow. - But it's just basically, it's using like Model
3 motors basically. - [Tim] Yeah, which is so cool. - Yeah, might as well use it. - [Tim] So you mentioned, you know, really trying to simplify it. There's been talks that they're not... Did you say it on Twitter that you're gonna eliminate
the cold gas thrusters or hot gas thrusters on the B4,
for the first orbital test? - Yeah, well we can move to like maybe a quieter location. I'm pretty sure we can cut
the weight of that in half, like that's, you know, we're not even really trying
to optimize the gauge. That's just basically plate. That's just like cut
plates welded together. First just got to like
making that thing work and then we'll optimize it. - [Tim] Yeah, of course. Which again is some of the
Soviet union was so good. It was like minimum
viable product basically, get it good enough to fly and test it. And obviously you guys
did that with Starship, big time with 8, 9, 10, 11, 15 was like, let's just get it out
there, see what works, see what doesn't and iterate, you know? - Yeah, and if you look at
like the various reasons, like why we blew up Starship is like, and you looked at the risk list, none of the reasons that
blew up are on the risk list. - [Tim] Really? - Yeah, it was like, no,
maybe you can argue like, one of them maybe was
on somebody's risk list, but it wasn't brought up beforehand, if you can put it that way. I mean, there's a crazy
amount of new technology happening here and it's all
evolving simultaneously, we need to iron out like
the unknowns sort of thing. Yeah, the unknown are the big ones. - [Tim] Is that the new
flaps for 20 down there? - Yeah. - [Tim] So remind me the numbering scheme. 'Cause you were talking
about version two Raptor, the other day, what we've seen so far, and are those original version two yet, like the green nozzles, those
aren't version two yet, right? Have you started making version two? - We've made parts of version two. So we've made the thrust chamber assembly. And we have, I think pretty much finished
the design of the pumps, we're gonna make the pumps. So hopefully we'll have either Raptor 2 in about a month we might
be testing the first one. - [Tim] Okay, and will that be, you said it you're going to be
kind of producing stuff or the prototypes are kind of
gonna be always in Hawthorne that eventually gonna be moving mass production to McGregor. - Yeah, we're doing volume production of Raptor and McGregor. We will keep California factory operating basically for development engines and the Raptor vacuum version. - [Tim] So if you're reaching
230 tonne on version two, what's that gonna be at, like 330 bar? - But technically, I think 298, but I think we should come on, we've got like get two more
bar out of that thing. - [Tim] Wait, wait, so even only 300, big air quotes on 300, you're
getting to 230 already? - Yeah, but then we're opening the throats and reducing the area ratio. The extra thrust is
like, there's a slight, I think we lose two or
three seconds of ISP, but we gain a lot more in thrust. And the increase in thrust
outweighs the slight drop in ISP. - [Tim] Yeah, especially
on the first stage. yeah. - I mean basically any thrust to weight below one is worthless. - [Tim] It's worthless, yeah. So if we go from .4 to .5, it's a massive leap compared to even... Yeah, yeah. - [Tim] Okay, so that makes total sense. So the Rap Vac currently what that for thrust? Is it still around that
same number about 200 tons? - The Raptor vacuum, or RVac as we put it We will actually be the
230 ton gross number is the thrust at sea level of the sea level version
of version two of the... It's essentially it's like
helpful to certainly like quibble about like, why are you talking about thrust in tonnes? That's not technically a scientific thing. It's because you can do the
math in your head really easily if you have a rocket in
tonnes and thrust in tonnes. - [Tim] Right, of course, - That's why, and Newton
has got like divide by 10 all the time. Which is like annoying. And then you only get kilograms
now you've got to like divide by 10,000 to get tons. Which is ridiculous. Okay, so you're like, this is absurd. Only a fool would use
Newtons in my opinion, if you're designing a rocket. And especially big rockets, 'cause you just like
have a zillion Newtons. But if you measure things in tons and you measure thrust in tons, now you know thrust weight very easily. - [Tim] Is that like
the only Imperial thing you measure then? - No, these are still metric tonnes. - [Tim] Okay, that makes sense. I was getting nervous for a second. - The pressure is in bar, 'cause everybody kinda knows
like what's one atmosphere. So but Pascal's another trash unit. I hate Pascals. That's why it's so tiny, it's absurd. - [Tim] We did have a whole
segment of units that Elon hates and it's just (laughs). - It's like units that
make understanding things more harder instead of easier. But everyone understands like a bar or an atmosphere essentially. And everyone like crew can
get their mind around a tonne. Like you have an
intuitive sense for a ton. Like your car is like two tons. - [Tim] You have some grasp,
you have some context. - Yeah, if you got hit by a
tonne, you'd know what that meant. If you got hit by a Pascal, that's like, I dunno a mouse fart. (laughs) That's like one Pascal. There's another important
principle, which is that, you really want everyone
to be chief engineer. So if everyone is chief
engineer means that people need to understand
the system at a high level to know when they are
making a bad optimization. It's like, like when they are like, because we've done this
many times where we've like put immense effort into
reducing the engine mass, but hardly any effort into
reducing proponent residuals or like order of magnitude, less evidence reducing
proponent residuals. And then you land with a
literal ton of unused fuel. And actually we still kind
of do that with Falcon 9. It has about a tonne of
unused fuel upon landing, which is pretty annoying. - [Tim] Oh, that's still not much in the grand scheme of everything. It's still not much,
but that is in context. So it still is quite a bit though. - Yeah, but like we spend so much effort getting a ton out of
engines, like, you know, that sort of whatever, like
130 kilograms per engine, like that's, yeah So that's like 120 ish. - [Tim] Wow, look, the sunsets out here are pretty hard to beat. That's insane. God, that's amazing. So congrats on the HLS
solidify a little more today. - That was cool. The GAO was a staunch
defender of good contracting. - Can we head over and
check out the mock-up there? Because there's still a lot
that we don't know about HLS publicly, at least. I assume that, you know,
a decent amout more. - I don't know if I do, but... - Well, first off, I
guess the most obvious one that I'm excited is those thrusters. - So the thrusters are a good example of running that algorithm
I just mentioned, laboriously mentioned, which is, a question to the requirements, making requirements based on deleted part. When we're looking at, what does the booster actually need to do with stage separation? If you put rotation into the stack like before you turn off the main engines. So they both rotating. They're gonna rotate and just- - [Tim] Wait, sorry. Like pitching and yawing or rolling? - So like you got the integrated stack. We do this with...
- [Tim] with Starlink!
- with Starlink. So we rotate the stage and- - [Tim] And kind of fling it out. - Yes, but they basically have different amounts of an inertia, essentially rotational
maybe to linear inertia. They basically move at different rates. So if you rotate the thing, depending on where you are, you will move at a different speed. And so it automatically separates if you rotate and then separate. So there's no actual separation mechanism for the Starlink satellites and they technically
can bump into each other and occasionally do, but if
they bump into each other, for like one mile an hour, doesn't matter. So there's bounce off. - [Tim] It's already made it through the pretty harsh environments of launch. - Yeah, it's fine. But like, I'm pretty sure this is like, this might be the only ride, we were like literally
tussling 60 satellites off with like a hay, bundle of
hay, like dry, you know? Dumping the rods that hold them down. Like a hay bale and just flinging them. And it's fine, then they just separate, split up and go to their position. So we've got to stage step, instead of asking the
attitude control thrusters, the reaction control thrusters to do the booster rotation,
which has a lot of force. You have the main engines
initiate rotation. Now this is quite complex space ballet. 'Cause everything has got to
happen in just the right way. But you basically initiate
the rotation of the stack, kind of stop the main engines. Then the two will actually
separate by themselves. And you need like a little bit, we have like cold gas ACS,
or reaction control system. It's like, depending on who you ask, it's a reaction control system, or an attitude control system. So it's basically like small maneuvering thrusters So you fire those on the ship that gives you a little
bit of maneuvering. And then on the booster, we actually have quite
a lot of ullage gas, like basically you've got a lot of hot gaseous
oxygen and hot methane, which actually have, you know, if you've got a big enough area, it's got decent thrust and vacuum. - [Tim] The actual- - The vents. But literally you use to
vent to vent the stage. - [Tim] Yeah, so not in a separate bottle, but literally like the ullage of the main tanks. - Yes. - [Tim] Okay. - So just use the ullage as your thrusters and just control the
orientation of the venting. So it is not just venting out sideways, but it is venting in a
direction that will just work. Which can be sideways sometimes. Anyway, we've got like basically
a lot of gas in this thing, which would have to actually
just vent to vacuum anyway. 'Cause it's got too much gas. And that's just extra
mass that you don't need. So if you've got basically
enough control authority because of the kicking
the whole stack over before main engine cut off, plus using the ullage gas to vent, you don't need a separate
hot gas thruster system. You don't even need a
cold gas thruster system. You already have hot gas. Question the requirements,
delete the part. - [Tim] But this is only
for the booster, right? - Yes. Although arguably, now you mentioned it, it might be wise to do
this for the ship too. - [Tim] You'd think that- - At least mostly well- - [Tim] Because the tanks are what, six or eight bar or something? The main tanks? - Yeah, there'll be like six-ish bar. - [Tim] And so one of those
would be pretty low pressure, low ISP gas thrusters. If you're only doing the gas from there, or is there some trick you can do to... - In vacuum, like it's this
different in atmosphere. Like six bar in vacuum is actually decent. It's like common to
have thrusters in space, thrusters that are, let's say eight bar, like the Draco thrusters
for that maneuver dragon are operating around
chamber pressure of around eight or nine bar. - [Tim] What? - Yeah. Like dragon is still in PSI. So it's like 120, 130 PSI. Technically it's a pressure
pulse, but you know, so 120 PSI is like roughly eight bar ish, maybe eight and a half bar. So it's not that far
from the tank pressure. - [Tim] Right. So you don't even need to store
the gas in an even higher, like in a bottle that's
like 200 bar or something. You don't even need to
do that to operate RCS. - No, if you've got a hot gas, first of all it's like, we really want the ullage
gas to be as hot as possible up to the point where it
is impacting the strength of a hull. Like we don't wanna
soften the metal so much that it pops basically. So the hotter the gas
is the higher the ISP. So having hot gas is good and it's already there and you already have the pressure vessel and you're gonna choke it away anyway. So obviously you just use
for attitude to control. So like, obviously... Initially you can't do this with the ship because everything's cryo, but once the ship is mostly
empty and you drive to orbit, it also is in the same
situation with a lot of hot gas. So actually we should really
be the vast majority of our maneuverings should be with
the hot gas that's in the ship. Thanks, now we are gonna fix that. - [Tim] So the thrusters on
HLS that are gonna be around the ring, the renders showed
like 24 or something of like- - Those are different. That's for landing on the moon. - [Tim] Okay, yeah, yeah. Are those pressure fed? Like, what are those? Do you have a name for
them yet or anything? - Let's just say like, this is the tentative design right now. But with the agreement with NASA, I think we may see that design evolve and it may be better actually. Like a big question here is like, can you land on the moon
with the main engines or do you need a separate thruster system that's way up there. Like basically, if you land
with the main engine, you're gonna dig a big ditch
in the moon and then fall over. 'Cause you landed in a ditch that you dug. It's like literally dig your own grave. That would be obviously bad. So we don't wanna dig our own grave and then fall in it. But more analysis is like, I think we could probably
land with the main engine and not dig a grave and die it, but we would have to prove that, you know, get something that's like, I don't know, the consistency
of like lunar regolith and like something that's like a good- - [Tim] A good analog. - Analog of that, and then like land the ship in that and
see how big is the hole that we're digging. If you've got low pressure
engines that have high up naturally, you're not
gonna dig a hole basically. So that's kind of like the sure thing. But I think if we can
prove that the main engines do not dig a giant hole, then we can land with the main
engines and then not have- - [Tim] Any of those, the ring. What about the, are you gonna have any sea level
Raptors on the lunar variant or we only have vacuum optimized? - [Tim] Because I assume like
on a normal star ship, even at stage separation, you'll probably light all six at first, just to minimize gravity
loss or something, right? So you'll still fire all
six then probably shut down the sea levels and let the back
of them optimize, you know, like they probably do what like, half the second stage
burn time or something with sea level or if you? - Well, so the vacuum
engines don't gimbal. So you'd have to have some things to provide the control authority. I mean, technically you
could say like, well, if you're in a low disturbance situation, like the moon has no atmosphere. Man, this is beeping city. - [Tim] You wanna move on? - Yeah. If you're not facing like a lot
of atmospheric disturbances, then you need much less control authority and you could probably land with three just by differential
throttling and three engines. But if you lost any of the engines, you'd be toast. So probably make sense to, I don't know, probably keep the same config, you know? - Or like you can even
just have one in the middle that would offer, you know, a decent amount of gimbal
authority and all that. - It's based on how much
optimization we're aiming for here. - [Tim] 'Cause you're only going to make one of these things, right? Or are you planning on like, is NASA wanting multiple or, oh, my word. So by the way, I think
there's a good chance that ITAR and comms might not want all of this. Wait until you see part
two is unbelievable. And I promise I'm going to
get it to as soon as I can. Thank you Elon, for spending
so much time with me and allowing me to ask all
of the questions I had. It was amazing. And thanks to the teams
at SpaceX for allowing me to share this all with you. And thanks to Cosmic Perspective
for helping shoot this and just kind of helping out all the time. Find them on YouTube
and on Patreon as well. And I owe a huge thank you
to my Patreon supporters for helping make this and
everything else we do here at Everyday Astronaut possible. If you want access to our discord channel, where we're probably going to be talking about this conversation a lot or live streams or lots of other fun stuff, head on over to
patreon.com/everydayastronaut. And while you're online, be sure and check out
our awesome web store. You can find shirts like this, the R7 / semyorka / the predecessor to Soyuz new shirt that
we have that is awesome. As well as our new Mars hats. We can also find some classics
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and schematics collection and lots of other fun stuff. So head on over to
everydayastronaut.com/shop. Thanks everybody, that's
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Honestly, even without Musk, its just nice to see the high bay and Starbase in general up close. Seeing inside the tents even! Man I've watched NASASpaceflight videos for over a year at this point watching Starbase expand and its honestly thrilling just seeing what its actually like.
As for getting hard info from Elon, he really does hit home the point that NOTHING they are doing there is final. I think he learned from his previous 2 BFR/ITS/Starship presentations completely changing gear each time - there's no point in saying they're gonna do it x way because its more likely they'd end up doing it a whole other way. I don't think we'll get any real hard new info from Elon because he simply doesn't know whats next himself.
Elon’s Design and Engineering Steps
Make your requirements less dumb (all requirements are dumb, make yours less dumb)
Delete the part or process (if you are not forced to add back in at least 10%, you didn’t delete enough in the first place)
Simplify or optimize (step three so that you are not optimizing a step which should be deleted)
Accelerate cycle time
Automate
Edit: steps
When Elon speaks about miscommunication about fire safety vs battery safety, I can't imagine stuff like that in a non-integrated environment with multiple contractors.. Billions poured down the drain.
This is fantastic!
Elon regarding B4 "The whole design is wrong the question is how wrong." So don't get too attached to this booster render artists!
As someone who works in an industry full of requirements, I feel this one....
Also, it amazes me he makes the time to do this stuff.
Here's the interesting stuff I remember after finishing the whole video with no intention of writing a summary. Please add more!
So it seems like non-folding grid fins will be permanent if it works out. Best part is no part. They shouldn't affect flight very much.
Tesla Model 3 motors are used to move the grid fins.
Booster mass is a moving target, probably 160-200 tons.
A lot of mass can be removed from the booster, including cutting the battery mass by a factor of 10 and probably halving the grid fin mass. Currently just flying whatever is good enough.
We get a good look at load points for picking up the booster. Sounds like these are the catching points as well.
Raptor 2 testing probably starting in about a month, there has never been a finished Raptor 2 yet.
Raptor 2: 230 tons of thrust at 298 bar (wants to push it to 300 of course)
Hot gas thrusters on booster won't have any intermediary tank, just straight from the big tanks to the thrusters. Around 6 bars of pressure is enough in a vacuum. Sounds like it wouldn't work very well in atmosphere.
Some speculation in the comments below that the hot gas thrusters might not actually combust the gas, just release it overboard like cold gas thrusters do. Kinda sounds like that's what Elon is describing.
Tim's question about hot gas thrusters on upper stage made Elon realize that would be a good idea and they're gonna do that. Funny!
Probably same engine config for HLS starship, and if they can prove starship can land on the moon without those extra landing thrusters they'll ditch em. Could prove this by landing starship on something that approximates lunar regolith without digging a huge hole.
Didn't learn much else about HLS starship, although we didn't go deep into it. Sounds like SpaceX doesn't know much themselves yet.
Part 2 seems to start with them walking into a tent with a bunch of Raptors, looking forward to that.
Starbase is noisy!
This is essentially the long awaited starship presentation for this year
For reference, the last time we had a detailed starship update was September 2019!
Starship stage separation: unlock the stage and fling it like Starlink 😎
Now we know why the tank vents are oriented like RCS for yaw and pitch.