The development of practical rockets for space travel was slow in the first decades of the 20th century.

From the 1900s to the 1920s, Tsiolkovsky wrote extensively, and mostly accurately, of the potential for liquid-fueled rockets to support orbital and interplanetary flight, correctly identifying H2/O2 as the highest specific impulse bipropellant and noting the value of staged rocketry. The theory is obviously important but most of the real barriers to this use of rockets were engineering problems, rather than physics problems per se, and Tsiolkovsky did not build real rockets.

Robert Goddard made the first steps towards practical long range rocketry. de Laval nozzles were already in use in steam turbines, and his decision to apply them to his rocket engines meant that he was able to build the first rockets with more than 50% efficiency. Before Goddard, rockets typically had efficiencies in the single-digits. The other significant advance he made as the use of electrically operated fins, controlled by 2-axis gyroscopes, to control attitude. He used compressed gas to force the fuel into the combustion chamber.

Unfortunately there was little public or financial support for Goddard’s work. Possibly with a bit more backing he would have been able to build larger rockets and perfect his guidance systems during the early 1930s. The greatest of his rockets never reached heights over a couple of km.

It was the Aggregat rocket program, headed by von Braun and worked on by such leading lights as Walter Thiel and Hermann Oberth, that made most of the engineering advancements required for a serious long-range, orbital or interplanetary rocket program. The Aggregat program culminated in the A4, better known as the V-2. It wasn’t just a scaled up version of previous liquid-fueled rockets, but instead relied on a number of new tecnhologies developed over a few years.

It’s quite remarkable that so many developments came together so quickly. To wit:

• Turbopumps driven by a steam turbines, powered by a reaction of sodium permanganate and hydrogen peroxide, to pump the fuel and liquid oxygen into the reaction chamber

• Radio controlled shut off and radio controlled guide beams

• Onboard analog computers to control the eight rudders, based on the output of the gyroscopes and integrating accelerometers. Indeed, these were the first electronic analog computers of any kind, built by Helmut Holzer.

• Variation of the fuel to liquid oxygen ratio with altitude to allow for a thrust profile best matched to the atmospheric pressure/altitude profile

Other developments that were useful though perhaps not crucial:

• Using the bipropellant to cool the reaction chamber (regenerative cooling): they didn’t invent this but developed the technique considerably

• Thermal shielding of the fuel and LOX tanks to prevent icing

Always liked the timing in this shot.

https://www.youtube.com/watch?v=2WoDQBhJCVQ

dv said:

The development of practical rockets for space travel was slow in the first decades of the 20th century.

From the 1900s to the 1920s, Tsiolkovsky wrote extensively, and mostly accurately, of the potential for liquid-fueled rockets to support orbital and interplanetary flight, correctly identifying H2/O2 as the highest specific impulse bipropellant and noting the value of staged rocketry. The theory is obviously important but most of the real barriers to this use of rockets were engineering problems, rather than physics problems per se, and Tsiolkovsky did not build real rockets.

Robert Goddard made the first steps towards practical long range rocketry. de Laval nozzles were already in use in steam turbines, and his decision to apply them to his rocket engines meant that he was able to build the first rockets with more than 50% efficiency. Before Goddard, rockets typically had efficiencies in the single-digits. The other significant advance he made as the use of electrically operated fins, controlled by 2-axis gyroscopes, to control attitude. He used compressed gas to force the fuel into the combustion chamber.

Unfortunately there was little public or financial support for Goddard’s work. Possibly with a bit more backing he would have been able to build larger rockets and perfect his guidance systems during the early 1930s. The greatest of his rockets never reached heights over a couple of km.

It was the Aggregat rocket program, headed by von Braun and worked on by such leading lights as Walter Thiel and Hermann Oberth, that made most of the engineering advancements required for a serious long-range, orbital or interplanetary rocket program. The Aggregat program culminated in the A4, better known as the V-2. It wasn’t just a scaled up version of previous liquid-fueled rockets, but instead relied on a number of new tecnhologies developed over a few years.

It’s quite remarkable that so many developments came together so quickly. To wit:

• Turbopumps driven by a steam turbines, powered by a reaction of sodium permanganate and hydrogen peroxide, to pump the fuel and liquid oxygen into the reaction chamber

• Radio controlled shut off and radio controlled guide beams

• Onboard analog computers to control the eight rudders, based on the output of the gyroscopes and integrating accelerometers. Indeed, these were the first electronic analog computers of any kind, built by Helmut Holzer.

• Variation of the fuel to liquid oxygen ratio with altitude to allow for a thrust profile best matched to the atmospheric pressure/altitude profile

Other developments that were useful though perhaps not crucial:

• Using the bipropellant to cool the reaction chamber (regenerative cooling): they didn’t invent this but developed the technique considerably

• Thermal shielding of the fuel and LOX tanks to prevent icing

Yes it’s an interesting topic.
I never realised that rocket engines were so complex and contrary.

I read a good book on the development of the V2 recently. It occurred to me they may have been able to shorten the development time a fair bit by using solid-fuel rockets rather than having to work out how to make nearly everything on a liquid-fuelled rocket work well enough. Note that solid-fuel rockets at that time also weren’t as advanced as the post-war scene, but I suspect the engineering effort to get enough performance may well have been easier & faster.

Spiny Norman said:

I read a good book on the development of the V2 recently. It occurred to me they may have been able to shorten the development time a fair bit by using solid-fuel rockets rather than having to work out how to make nearly everything on a liquid-fuelled rocket work well enough. Note that solid-fuel rockets at that time also weren’t as advanced as the post-war scene, but I suspect the engineering effort to get enough performance may well have been easier & faster.

The skyrockets of cracker night fame used to go pretty good for primitive solid rockets.

Neophyte said:

Always liked the timing in this shot.

https://www.youtube.com/watch?v=2WoDQBhJCVQ

Nice!

:)

Neophyte said:

Always liked the timing in this shot.

https://www.youtube.com/watch?v=2WoDQBhJCVQ

LOL “Destination, the Moon or Moscow.”

Neophyte said:

Always liked the timing in this shot.

https://www.youtube.com/watch?v=2WoDQBhJCVQ

I loved Burke back in the day. The Real Thing was one of my favourite shows.

Spiny Norman said:

I read a good book on the development of the V2 recently. It occurred to me they may have been able to shorten the development time a fair bit by using solid-fuel rockets rather than having to work out how to make nearly everything on a liquid-fuelled rocket work well enough. Note that solid-fuel rockets at that time also weren’t as advanced as the post-war scene, but I suspect the engineering effort to get enough performance may well have been easier & faster.

In some ways, yes.
They would still have had to solve the guidance and attitude issues, though.

dv said:

In some ways, yes.
They would still have had to solve the guidance and attitude issues, though.

Yes that took them a fair while as well, pretty much as long as it took the liquid-fuelled engine to be made to work with the reliability & power required.

Spiny Norman said:

I read a good book on the development of the V2 recently. It occurred to me they may have been able to shorten the development time a fair bit by using solid-fuel rockets rather than having to work out how to make nearly everything on a liquid-fuelled rocket work well enough. Note that solid-fuel rockets at that time also weren’t as advanced as the post-war scene, but I suspect the engineering effort to get enough performance may well have been easier & faster.

i suspect von braun knew this

solid fuel rockets if developed by scientists would have been able to be launched in much greater numbers daily, most likely by trucks requiring nothing more than pipes welded together aimed in the right direction and angle (you’d account for wind direction) or presumably take some ranging shots and use fast moving aircraft to spot where they were coming down. if von braun had wanted to make missiles i doubt if it would have taken years or the serious amounts of money they spent.

von braun was making moon machines not missiles, liquid fuel rockets take too much time to set for firing to be useful in a wartime situation. given that germany was quickly losing air superiority it should have been obvious that a quick set up and firing rocket system should have been set up. imagine if the nazis had a thousand of trucks carrying say 10 missiles each that could travel a great distance, D – day would have been a disaster.

the V2 was really an experimental device i suppose.

the yanks used to launch satellites in scout rockets till the early 90s i think.

> The theory is obviously important but most of the real barriers to this use of rockets were engineering problems, rather than physics problems per se

I found that out myself :-(

dv said:

…

It’s quite remarkable that so many developments came together so quickly. To wit:

• Turbopumps driven by a steam turbines, powered by a reaction of sodium permanganate and hydrogen peroxide, to pump the fuel and liquid oxygen into the reaction chamber

• Radio controlled shut off and radio controlled guide beams

• Onboard analog computers to control the eight rudders, based on the output of the gyroscopes and integrating accelerometers. Indeed, these were the first electronic analog computers of any kind, built by Helmut Holzer.

• Variation of the fuel to liquid oxygen ratio with altitude to allow for a thrust profile best matched to the atmospheric pressure/altitude profile

Other developments that were useful though perhaps not crucial:

• Using the bipropellant to cool the reaction chamber (regenerative cooling): they didn’t invent this but developed the technique considerably

• Thermal shielding of the fuel and LOX tanks to prevent icing

I’ll need to check the timing of those.

I realised a few years ago that the speed of all technological development slows in wartime, and I mean all, even military technology.

For example, the increase in aircraft speed between 1939 and 1944 was negligible compared to that between 1945 and 1950.

mollwollfumble said:

I realised a few years ago that the speed of all technological development slows in wartime, and I mean all, even military technology.

For example, the increase in aircraft speed between 1939 and 1944 was negligible compared to that between 1945 and 1950.

Not all technologies. For example burns treatment was improved somewhat in WW2.
The speed increase is simple enough to explain, as before WW2 there were no jets, some during, and after WW2 there were. Same for rocket-powered aircraft. The war demonstrated the need for faster aircraft, etc.
The atomic bomb is another; it only really happened because of WW2 and the threat of Germany possibly developing a bomb, (they weren’t really) so the US decided to get there first no matter the cost. When it became apparent that Germany was going to lose their war, the bomb effort was them targeted to Japan. We all know how that went.

Seems strange that they would test a solid booster rocket in the horizontal position
I would have thought that gravity would have played some part in the propellant feed system but it’s probably a pressurised gas system.

https://www.bbc.com/news/av/science-environment-54006573

Peak Warming Man said:

Seems strange that they would test a solid booster rocket in the horizontal position
I would have thought that gravity would have played some part in the propellant feed system but it’s probably a pressurised gas system.

https://www.bbc.com/news/av/science-environment-54006573

If it’s solid fuel wouldn’t it burn from the bottom to top without any fuel movement.

Tamb said:

Peak Warming Man said:

Seems strange that they would test a solid booster rocket in the horizontal position
I would have thought that gravity would have played some part in the propellant feed system but it’s probably a pressurised gas system.

https://www.bbc.com/news/av/science-environment-54006573

If it’s solid fuel wouldn’t it burn from the bottom to top without any fuel movement.

No. The fuel mass has a hole bored down the middle of it which acts as a combustion chamber, and which increases the surface area of fuel exposed for ignition by the igniter, which is usually at the top of the fuel mass.

So, it burns from the inside towards the outside.

captain_spalding said:

Tamb said:

Peak Warming Man said:

Seems strange that they would test a solid booster rocket in the horizontal position
I would have thought that gravity would have played some part in the propellant feed system but it’s probably a pressurised gas system.

https://www.bbc.com/news/av/science-environment-54006573

If it’s solid fuel wouldn’t it burn from the bottom to top without any fuel movement.

No. The fuel mass has a hole bored down the middle of it which acts as a combustion chamber, and which increases the surface area of fuel exposed for ignition by the igniter, which is usually at the top of the fuel mass.

So, it burns from the inside towards the outside.

Yes. Now I remember. Thanks.

Spiny Norman said:

mollwollfumble said:

I realised a few years ago that the speed of all technological development slows in wartime, and I mean all, even military technology.

For example, the increase in aircraft speed between 1939 and 1944 was negligible compared to that between 1945 and 1950.

Not all technologies. For example burns treatment was improved somewhat in WW2.
The speed increase is simple enough to explain, as before WW2 there were no jets, some during, and after WW2 there were. Same for rocket-powered aircraft. The war demonstrated the need for faster aircraft, etc.
The atomic bomb is another; it only really happened because of WW2 and the threat of Germany possibly developing a bomb, (they weren’t really) so the US decided to get there first no matter the cost. When it became apparent that Germany was going to lose their war, the bomb effort was them targeted to Japan. We all know how that went.

> For example burns treatment was improved somewhat in WW2.

Hardly. Even now, nothing can beat a bath in cold water. Unless you mean artificial skin, but that was developed in the 1970s.

> The atomic bomb is another.

Yeah. OK. Nuclear technology was coming anyway, but not for bombs.

The cavity magnetron is another wartime invention. But it would have come anyway, being an improvement on the klystron which was pre-war.

mollwollfumble said:

> For example burns treatment was improved somewhat in WW2.

Hardly. Even now, nothing can beat a bath in cold water. Unless you mean artificial skin, but that was developed in the 1970s.

Example 1
Example 2