But our grandfathers' Space Corps existed, and still exists [1]. And it stood strong. It's just that the force it stood against was the United States and NATO (or, from the opposite perspective, the Soviet Union and the Warsaw Pact), and the landing pods were the tens of thousands of nuclear-tipped ICBMs built with the same technology that was showcased in programs like Apollo and Soyuz.
One of the literally marvelous phenomena of the twentieth century is how good people were at pretending that this wasn't happening. It's not just nostalgia: People ignored the militarization of space in real time. Werner von Braun was able to literally drop ICBMs on people's heads, then move to the USA and continue developing ICBMs, all the while maintaining, and apparently sincerely believing, that the ICBMs were not the real story, that the real story was the impending colonization of space. And everyone went along with that, except during Tom Lehrer concerts, when they permitted themselves a little chuckle at the irony of it all.
(I blame World War II. I don't think it's possible for young folks like me to really understand how apocalyptic World War II was. The aspects of the 1960s that scare me witless, like the Cuban Missile Crisis, felt normal to people who had lived through World War II.)
Unfortunately, though, the USA wasn't actually paying von Braun for moon rocks, they were paying for ICBMs. And I don't think it's a coincidence that, once the ICBMs were finished, the money started drying up. Space research is stalled for the same reason that the US military still flies B-52s, designed in the late 1940s: Flight is a solvable problem, and it was solved. ICBMs ended up being overengineered: We have amazing ICBMs, with lightweight warheads, that remain perfectly capable of accomplishing their core mission of destroying all the major cities of the world. That research is finished, and our major concern today is the delicate political task of destroying our remaining ICBMs and never building any more.
In the absence of a military motive, there's a lot less money for space. [2] The good news is that the money isn't quite zero, and our amazing advances in robotics stretch it a lot farther.
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[1] I've heard that it's the worst job in the Air Force and the personnel involved are absolutely miserable: Spending all day maintaining their doomsday weapons, never able to act, praying that they never have to act, knowing that nobody may be alive to admire them if they ever do act, constantly wondering what decision they'll make when the button gets pressed. Drinking, presumably. Watch the first few minutes of WarGames: Those soldiers are based on real people, and their reactions are based on real drills. They're the unsung heroes of the last fifty years. If they don't do their work with care, we might all die, and nobody wants to think about them.
[2] To be precise: There is still plenty of military motive to launch things into space, and plenty of money too. But we now know that the strategic purpose of space is to hold lightweight satellites that watch stuff on the ground, and those satellites are increasingly small and disposable. In the early 1960s we didn't yet know that we wouldn't have much use for gigantic launch vehicles the size of the Saturn V, and we didn't know how microcircuitry was going to happen.