[WalterBright]

Haven't changed since Goddard? Oh my! Here's a list of the innovations the Germans made to Goddard engines in order to scale them up for the V2:

1. turbo-pump

2. building a jacket into the nozzle to both cool the nozzle and pre-heat the fuel

3. putting tiny holes in the jacket so the leaking fuel would form a boundary layer that would protect the nozzle from heat

4. baffles in the combustion chamber to damp out pogo-ing

There's a picture of Goddard looking at a captured V2 engine with his mouth hanging open in astonishment.

The Saturn V engines were scaled up V2 engines.

[avmich]

> The Saturn V engines were scaled up V2 engines.

That's very debatable :) - everything is everything else, if squinting hard enough. Just an injector head of F-1 was a serious R&D topic, with whole methods of experiments invented.

[WalterBright]

Obviously there was a lot of refinement and development going on in those engines.

For another example, the Ohain axial flow turbojet is quite recognizable even up to modern jet engines. The Whittle radial flow turbojet was a dead end.

Innovations 1..3 are all revolutionary, not evolutionary, advances in rocket engines. 4 maybe is.

https://airandspace.si.edu/collection-objects/v-2-rocket-eng...

The Saturn V engines needed much more powerful turbopumps, and so used a secondary rocket engine just to drive the pump. How cool can you get?

[panick21_]

> The Saturn V engines were scaled up V2 engines.

I mean, not really. They were a totally different cycle type. Different fuel. Different way adjusting trajectory. Different injectors.

Seems pretty different to me.

[WalterBright]

Different cycle type? I'm interested - what's different?

[panick21_]

I mean one uses the main propellant to drive the turbine the other has a sodium permanganate/hydrogen peroxide. That seems to me a pretty significant difference in how the engine works.

To be fair, technically one could call both gas generators but its still significantly different.

[WalterBright]

I'm sorry, but picking a different source of hot gas to drive the turbopump is not a conceptual difference. Just like adding nitrous injection to your car doesn't make it a conceptually different engine.