Jeff Bezos

You get more benefit from the higher specific impulse on the second stage. And that stage carries less propellant, so you don't get such geometrically gigantic tanks. The Delta IV is an example of a vehicle that is all hydrogen. The booster stage is also hydrogen. And I think that it's a very effective vehicle, but it never was very cost effective.

So it's operationally very capable, but not very cost effective.

So it's operationally very capable, but not very cost effective.

So it's operationally very capable, but not very cost effective.

Size is costly. So it's interesting. Rockets love to be big. Everything works better. What do you mean by that? You've told me that before.

Size is costly. So it's interesting. Rockets love to be big. Everything works better. What do you mean by that? You've told me that before.

Size is costly. So it's interesting. Rockets love to be big. Everything works better. What do you mean by that? You've told me that before.

I mean, when you look at the physics of rocket engines, and also when you look at parasitic mass, Let's say you have an avionics system, so you have a guidance and control system. That is going to be about the same mass and size for a giant rocket as it is going to be for a tiny rocket. And so that's just parasitic mass that is very consequential if you're building a very small rocket.

I mean, when you look at the physics of rocket engines, and also when you look at parasitic mass, Let's say you have an avionics system, so you have a guidance and control system. That is going to be about the same mass and size for a giant rocket as it is going to be for a tiny rocket. And so that's just parasitic mass that is very consequential if you're building a very small rocket.

I mean, when you look at the physics of rocket engines, and also when you look at parasitic mass, Let's say you have an avionics system, so you have a guidance and control system. That is going to be about the same mass and size for a giant rocket as it is going to be for a tiny rocket. And so that's just parasitic mass that is very consequential if you're building a very small rocket.

but is trivial if you're building a very large rocket. So you have the parasitic mass thing. And then if you look at, for example, rocket engines have turbo pumps. They have to pressurize the fuel and the oxidizer up to a very high pressure level in order to inject it into the thrust chamber where it burns. And those pumps, all rotating machines, in fact, get more efficient as they get larger.

but is trivial if you're building a very large rocket. So you have the parasitic mass thing. And then if you look at, for example, rocket engines have turbo pumps. They have to pressurize the fuel and the oxidizer up to a very high pressure level in order to inject it into the thrust chamber where it burns. And those pumps, all rotating machines, in fact, get more efficient as they get larger.

but is trivial if you're building a very large rocket. So you have the parasitic mass thing. And then if you look at, for example, rocket engines have turbo pumps. They have to pressurize the fuel and the oxidizer up to a very high pressure level in order to inject it into the thrust chamber where it burns. And those pumps, all rotating machines, in fact, get more efficient as they get larger.

So really tiny turbo pumps are very challenging to manufacture. And any kind of gaps between the housing, for example, and the rotating impeller that pressurizes the fuel, there has to be some gap there. You can't have those parts scraping against one another. And those gaps drive inefficiencies. And so if you have a very large turbopump, those gaps in percentage terms end up being very small.

So really tiny turbo pumps are very challenging to manufacture. And any kind of gaps between the housing, for example, and the rotating impeller that pressurizes the fuel, there has to be some gap there. You can't have those parts scraping against one another. And those gaps drive inefficiencies. And so if you have a very large turbopump, those gaps in percentage terms end up being very small.

So really tiny turbo pumps are very challenging to manufacture. And any kind of gaps between the housing, for example, and the rotating impeller that pressurizes the fuel, there has to be some gap there. You can't have those parts scraping against one another. And those gaps drive inefficiencies. And so if you have a very large turbopump, those gaps in percentage terms end up being very small.

And so there's a bunch of things that you end up loving about having a large rocket and that you end up hating for a small rocket. But there's a giant exception to this rule. And it is manufacturing. So manufacturing large structures is very, very challenging. It's a pain in the butt. And so if you're making a small rocket engine, you can move all the pieces by hand.

And so there's a bunch of things that you end up loving about having a large rocket and that you end up hating for a small rocket. But there's a giant exception to this rule. And it is manufacturing. So manufacturing large structures is very, very challenging. It's a pain in the butt. And so if you're making a small rocket engine, you can move all the pieces by hand.

And so there's a bunch of things that you end up loving about having a large rocket and that you end up hating for a small rocket. But there's a giant exception to this rule. And it is manufacturing. So manufacturing large structures is very, very challenging. It's a pain in the butt. And so if you're making a small rocket engine, you can move all the pieces by hand.

You could assemble it on a table. One person can do it. You don't need cranes and heavy lift operations and tooling and so on and so on. When you start building big objects, infrastructure, civil infrastructure, just like the launch pad and the, you know, all this, we went and visited it and took you to the launch pad and you can see it's so monumental.