What is the earliest point in history for a viable space program?

[DougM]

It tooks many many hours if not days to move the largest artillery as it had to be taken apart loaded on a train then moved and set up again. So I doubt you re moving larger gun far enough to clear a nuclear blast in the short time it would take to shoot from the US to the USSR

 

[Kalga]

By a decade or even more, if the world wars (and similarly large wars) do not happen, but [realistically] that there's still friction and competitive nature between the great powers (and their flunkies).

"But what about all the scientific and technological innovation from those wars?"

Bruh OTL got the large slice of a much smaller pie. The wars consumed and destroyed vast quantities of resources, labor, and talent. Most of those creating off the shelf* hardware and the stuff of yesterday*. A world of a longer Belle Époque isn't going to stay stuck with their tech level (nor fashion, but predicting that's a crapshoot).

*Most of the German WWII production weren't their supertech, but their pre war existing stuff (and modifications), even late into the war. For a specific WWI example the Royal Navy's R class battleship was a downgrade from their previous class.

 

[NHBL]

"But what about all the scientific and technological innovation from those wars?"

That is the point of my "Reach for the Skies," to get an ongoing war level push for technological development while reducing the wars. That does mean that the next war the United States is in will be a RUDE shock to the Europeans, who underestimated how MUCH the "rocket technolgy" they were wasting their money on had spin off effects. (Late Great War fire control on one American battleship in the War of 1897 will be a VERY unpleasant shock to a lot of people.)
From 1897 until the Great War, they will close the gap.

I will note that I am trying for a plausible rate of advance--we won't see moonshots in 1910 or anything...

 

[Juumanistra]

I’ve been pondering this question. Originally, I was thinking someone like Howard Hughes, an early Elon Musk, was the solution. However, the sheer breadth of what would need to be done makes that scenario unlikely. Then it hit me.

Robert Heinlein.

You know, someone should write a timeline about Robert Heinlein becoming enmeshed in the Navy's quite serious and sadly mostly forgotten space ambitions. I'm sure there are interesting things you could do with that. Cough, cough, shameless plug, shameless plug.

I think the Navy brass finds a way to keep the research going, particularly considering the need to keep the Navy relevant. The Army Air Corps at this point is selling the A-bomb carrying bomber as the wave of the future and cheaper than all these carriers the Navy is talking about funding. In OTL, there was a very nasty political/congressional fight over the issue culminating the ‘revolt of the admirals’, that’s what it was called believe it or not. The Truman administration wound up siding with the Air Corps and the Navy found itself constantly on the backfoot.

In this TL, the rocket/satellite program is something the Navy can use to stay relevant, so the funding continues by nook and cranny. Even if the funding is completely shutdown the idea and some infrastructure is in place and someone else can pick up the slack. Someone like Howard Hughes or someone in the corporate world who can see the future benefits of the project.

Except that IOTL, the Navy did have an orbital rocket program from 1945 until 1948. It was the High Altitude Test Vehicle, helmed by the Committee for Exploring the Feasibility of Space Rocketry. The boys at CESFR just wanted to put a thousand-pound satellite into a several hundred nautical mile-high orbit using a single-stage hydrolox rocket. Nothing too technically daunting there, natch.

HATV, of course, died a brutal death because of just how ridiculously tight budgets were during the post-WW2 demobilization. And that it was trying to do a great amount of technological groundbreaking as well. About the greatest contribution of HATV was helping build the first H-Bomb, which is no small feat for a program that's even a bit obscure among space cadets. (Aerojet did a good deal of the yeoman's work in figuring out how to produce liquid hydrogen at scale and their liquifier they built for HATV-related work eventually got sent to Eniwetok.)

Also, research into the Atlas rocket program started in 1946 OTL. It was canceled and restarted several times and not really taken that seriously until Sputnik. In this TL, the research program continues without interruption.

If we're splitting hairs, HIROC and Atlas were different things. But ultimately Karel Bossart had in his mind's eye a balloon-tanked ICBM, so I suppose that's just a niggling quibble. The more practical problem is that Atlas is a ballistic missile and there are hard limits to how much you can accelerate that. As warhead miniaturization and the guidance revolution are both necessary and it's very hard to have them happen earlier than they did. You can still have commsats and rockets to launch them without ballistic missiles, but they're going to have nowhere near the resources that are going to be thrown at ICBMs. And without those resources, your development timelines get greatly extended. (Which is a problem which plagues the entire scenario: You can only accelerate spaceflight over its OTL timeline with an earlier and even more titanic expenditure of resources and it's very, very hard to get those resources without guided missiles being the justification.)

Small quibble. I suspect that first satellite launch vehicle would be more like the smaller, multi-stage rockets used by Explorer 1 than the modified R-7 rocket used for Sputnik.

It's not at all hard to get a V-2-based orbital launcher, honestly. It'd be very al-Abid-like, with a cluster of V-2s in the first-stage and then smaller clusters as you gup the pyramid. Assuming you can't spare the engineering time and resources to do bespoke upper stage(s), which is actually an interesting writing challenge to justify why you'd be that hard-up to not do things properly short of the conditions von Braun was operating out of by 1944-45. And if you've got something Redstone-sized that isn't built of steel girders, even better and easier.

Another thought--Theoretically, an underground nuclear bomb could launch a satellite into space. During one underground nuclear test in the mid-50s, calculations prove that a steel manhole cover would have been launched into orbit had it not been vaporised. So maybe have an early nuclear test be underground (for secrecy, for safety, who knows) and have it launch some similar object sky high and someone puts two and two together and realises they've made the world's most powerful gun and the Jules Verne-style cannon is actually feasible. Problem at that point is making a satellite that can survive the launch since that's an insane amount of G-forces to survive. This sort of "hole in the ground" launch system is fairly limited too in terms of what you can launch, since for a bigger satellite and probably manned spaceflight you'll need the famous Project Orion nuclear pulse engine (i.e. shooting atomic bombs out the back of the ship and letting them slam into a pusher plate).

So this possibly means the first satellite before 1950 and perhaps also means the Orion drive is seen as a perfectly reasonable way to launch something into space. Maybe with knock-on effects like Project PACER is seen as a reasonable way to generate energy and other "peaceful nuclear explosions" programs. Downside is the environmental/anti-nuclear movement would come down hard on spaceflight meaning things might not be much ahead of OTL, but if the nuclear lobby/space lobby is strong enough and there's a strong belief that space activities can save the natural environment from hydro dams or mining and make green energy both cheap and environmental (for when global warming becomes a concern) then it might be mitigated.

The Verne Orion is one of my favorites. Bonus points for referencing PACER, which remains the only fusion power plant we've yet discovered that produces meaningful amounts of net energy. But I mostly want to see the Verne Orion happen to see the absolute monster of a pulse-unit necessary for it. As I've always seen it described with a 10 MT pulse-unit, which is not small thermonuclear warhead in its own right, before getting to making it a shaped charge and packing it with enough propellant to make use of that much explosive force.

Alternatively, you might have the nuclear launches go away entirely in favor of something like Gerald Bull's Project Babylon space gun. A gun that size (Bull's gun had a 1 meter bore) could launch small, sturdy satellites and fulfill at least some of the demand for space satellites. That could get military funding too if theoretically one could alter the gun's trajectory and let it point directly at [insert Soviet/Chinese city] and drop some nuclear artillery shells--the shells are cheaper than a missile and with some artillery tractors or a train it could be moved about and thus potentially difficult to eliminate in a nuclear war. I'm not sure how early you could have space gun technology and the capability to launch any sort of satellite which could survive the gun being fired, but it's obviously a very old and popular idea thanks to Jules Verne.

I want to say I recall hearing somewhere that someone, at some point, proposed building a gargantuan turn-table to mount HARP on following the verification of Martlet's sat-launching capabilities, to allow the gun to optimize launch trajectories as well as open up new ones. But that could easily be an observation made twenty years after the fact, hindsight saying that's a good idea, or just sheer conjuring from the ether, because it is a good idea. Or equal parts of all three.