I've been using the freeware version of RPA, and I have to make some allowances. Like, the low grade version doesn't have any modules to account for how one pumps the propellant for instance. But it does the chemistry for me anyway. This is why I can have some idea what the right expansion ratio is for the SL version of some engine, but I have no way except analogy to do that for atomic systems.
Let's do rocket engineering from the beginning
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I don't have that. However, 25 years of mechanical engineering experience gives me a very good idea of what the thermodynamic nightmare that says "hello" looks like when the pressures and/or temperatures are outside of what the materials you have access to can handle.
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I find it personally hilarious that the OP specifies that the biggest explosive source this society has access to is black powder, and one of the first questions is 'what about nuclear'.
Outside of the physical parameters of the planet -- if orbit is easy enough even simple black powder could do the job, albeit rather dangerously -- I think the big question is what this society has access to in the way of general purpose hydrocarbon refinement, because that dictates whether you can use kerolox setups or need to resort to something even more old-school.
Outside of the physical parameters of the planet -- if orbit is easy enough even simple black powder could do the job, albeit rather dangerously -- I think the big question is what this society has access to in the way of general purpose hydrocarbon refinement, because that dictates whether you can use kerolox setups or need to resort to something even more old-school.
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The Δv required to reach low orbit from the Earth's surface is about 9.4km/s. That's too much for single stage to orbit with a useful payload.
Two stage and and stage-and-half (Mercury-Atlas and Vostok anyone?) works.
As for getting to outer space on a suborbital trajectory? The very first picture taken from outer space was done using a captured V-2 with a camera instead of a warhead in 1946.
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I don't see a mention of SSTO requirement anywhere, and if there was, I'd ignore it.
Like, ultimately, orbital and suborbital hops can be done without particularly high-proof fuel mixes. The V2s you mention ran on alcohol. But you specified that they could produce, albeit not store long-term, LOX, which means that the real interest, at least for liquid rocketry, is on the fuel side. Hence my question about what kind of refinery capabilities there are to deal with. From your reply I'm assuming we're dealing with, functionally, Earth, in terms of orbital parameters and such.
Cloak&Dagger
Definitely Insane
For ground-to-space nuclear engines to be cheap, you need either an Orion Drive or an air-breathing rocket, not just a chemical rocket with a nuclear reactor attached, that gives up the entire advantage of a nuclear engine and makes it useless. At least for low-tech nuclear engines.
I was assuming that they were a peaceful species or whatever. The question is pointless otherwise, you aren't going to space in any meaningful capacity with pre-1945 technology.
Could you theoretically destroy the economy of an early 1900's state to make a big pile of explosives that might detonate in proper sequence and get something to space intact? Uh, maybe, sure, but that's not particularly useful.
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You can't build a nuclear bomb with black powder, you goof.
Cloak&Dagger
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You could make a nuclear bomb with no explosives at all, it doesn't have to have an explosive trigger.
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While true, assuming you had some other means to achieve criticality such as perhaps a railgun, any attempt to build the kind of bombs needed for an Orion setup requires implosion.
Cloak&Dagger
Definitely Insane
Criticality is just having enough of a fissile material in an area to continue a fission reaction. Get some highly enriched material and you can do that with just a screwdriver. There's nothing special about explosives for making nukes, and if you wanted you could use black-powder or air-guns for early nukes. Later designs would be different, but presumably this society would get better explosives, or just make alternative designs to our current implosion ones.
As far as Orion, it's very simple. You can fire any kind of nuke out of the end. Obviously a Little Boy is going to be much less efficient than a shaped-charge thermonuke, but you're competing against black powder rockets, so there's going to be absolutely no competition in cost per ton into orbit.
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Fat Man was a plutonium implosion weapon. The criticality event with the screwdriver would not be practicable for a nuclear bomb, and yes you could try to use black powder for a gun weapon but, as I reiterate, gun weapons won't work with an Orion concept.
This is your same damn hobby horse you always come in on.
Cloak&Dagger
Definitely Insane
A gun nuke is obviously going to be less efficient, yes, but the pusher plate doesn't really care what generated the force pushing into it.
Come to think of it, if you want to get really silly, for ground launches you could have Pusher-Plate spacecraft with no actual nukes on board, and just have guns on the ground shoot them with nukes to fling them into space (after they're lifted from the launch site by a prepositioned nuke).
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For this thought exercise the question of "can they build a nuclear bomb?" is meaningless because their answer to the question of "do we need something like that?" is a "NO!" issued with prejudice.
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BTW, when I said I wanted the right side of the complete combustion reaction to be only carbon dioxide and water to avoid fouling up the environment I wasn't joking. If there's any nitrogen in the mix you'll get some NOx. If there's both nitrogen and carbon in the mix there will be some cyanides too. Getting rid of such pollutants is why your car has a catalytic converter.
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Don't get me started on what tetraethyl lead does to everyone nearby when it's used to allow high compression ratios with gasoline. You will not like what I have to say.
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If they can store Liquid oxygen, then they can probably also store Liquid fluorine, which gives you that little extra highly reactive kick needed for all the fun chemistries. Who doesn't want to trade a few extra seconds of impulse for highly reactive fluoride byproducts in the upper atmosphere and an increase in the difficulty of handling by, oh, not much more than an order of magnitude.
You could also try for chlorine triflouride. You can keep it liquid much easier than pure fluorine, and all for the extra costs of explosive decomposition if it meets any contaminants!
Pair it with something like Kerosene and you're well on your way to space and ozone depletion!
You could also try for chlorine triflouride. You can keep it liquid much easier than pure fluorine, and all for the extra costs of explosive decomposition if it meets any contaminants!
Pair it with something like Kerosene and you're well on your way to space and ozone depletion!
Aperture lemon
Eat this and you will get super powers or tumors
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I wonder how much cheaper rocketry, planes, etc would be on a planet with like 80% earth gravity? Some civilizations could luck out or lose out leaving their planet with chemical rockets.
Cloak&Dagger
Definitely Insane
On the contrary, without nuclear war leading to nuclear hysteria, there's all kinds of useful stuff you can do with nukes, besides engines like we're discussing here.
Other than Orion as an engine, you could also have a nuclear Verne Gun to launch things into space.
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Sandy River DL
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You need to explain where the idea would even come from in this scenario. Nukes didn't invent themselves after all and anyone crazy enough to say 'let's invent bombs capable of flattening cities so that we can launch small towns into space' would be more likely to be tossed into a mental hospital than being taken seriously.
Cloak&Dagger
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Physics research, same as particle accelerators, and the obvious potential for mining and construction these were used for.
Sandy River DL
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Then you'd be more likely to get some sort of quickly abandoned particle beam rocket than Orion Drives. Also, given that subsurface nukes vaporize the immediate surrounding and cause neutron activation in what survives, they're terrible for mining. Turning ore into lung cancer fog ain't exactly going to be an economic success. Seriously, try actually reading the entirety of those wiki articles you posted.
There is another thread going right now about ASB (query if that initialism is not familiar) habitable Venus--we are quarreling about how habitable is possible.
Assuming an alternate Venus is the same mass and radius, surface gravity is about 90 percent, radius about 95 percent, these taken together mean potential energy near the surface of 85.5 percent, enough to substantially lower orbital speed; gravity loss would be lower, though assuming the same surface barometric pressure with similar air composition the air drag would be about 10 percent higher (that is, pressure and density fall off more slowly under the lower gravity so scale height is greater--also we have to finish deciding what the surface temperature is for atmospheric details).
Through a rather involved sequence, I estimate that while Starship is supposed to put about 150 tonnes of cargo into LEO, launched from Venus (if it had an atmosphere similar to Earth's) it would be more like 215 tonnes, a 43 percent improvement.
Starship itself, even if up-engined with three more SL engines so as to have a substantial positive balance of thrust after dead weight is deducted, rather than the negative one we'd have with the currently projected 6 engines (pretending the Vacuum engines as well as SL engines could produce useful thrust at sea level; with modifications this might be possible) still cannot reach orbit around Venus by itself. On either planet, the booster stage is needed, though I suppose we could get by with a smaller VenusHeavy designed for the lower gravity--but that would just reduce the payload.
Going down to 80 percent Earth G should improve more on that, but making a SSTO vehicle remains a stunt.
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Einstein didn't believe black holes existed. I know how to prove they do exist using only classical physics because every object has an orbital velocity and escape velocity equal to the speed of light.
I consider reaching orbit the practical definition of "reaching space," though I have noted if two rival powers were in a space race, and one developed the ability to reach orbit, the other would still be able to shoot down the more advanced nation's orbital vehicles with suborbital buckshot or other interceptor concepts.
Military applications seem close to certain to dominate early rocket research. I should note that one reason the German Army was willing to fund the German amateur rocket community was that the Versailles Treaty prohibitions did not apply to rockets, simply because none of the Allies involved in writing the restrictions thought of rockets as a serious weapons system; it just did not cross their minds. So the German military could pursue rocket artillery quite legally.
Also, the fact that the V-2 burned alcohol and LOX meant fueling them did not impact on the scarce petroleum or synthesized hydrocarbons the Third Reich had available in the end game of the war they started.
Ultimately, all the powers involved in WWII did turn to rockets for various important and practical applications--anti-tank missile systems like the Bazooka and Katusha, JATO units to improve airplane takeoff abilities. But these tended to favor solid rockets.
The British Interplanetary Society turned to solids for their wartime developed Moon expedition proposal, because the members had a hard time envisioning how liquid fueled systems would deliver propellant at the rates they figured would be required.
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You are a fool. For this society there are no wars there is no space race.