I didn't want to shit up the Astronomy thread, but I found it interesting the newfound fascination with getting to the moon.
Suddenly China, India, and the US are all attempting it.
There's a theory that I saw a long time ago that says that most inventions are inevitable; if one inventor didn't invent it, there'd almost definitely be someone coming along shortly thereafter to do it. Even with space travel this seems to be the case where we had a few different companies suddenly in the race to try to get the first person into orbit commercially. And so now we see a bunch of governments attempting to go to the moon, and it seems to me we hit the threshold for it to be actually feasible. Which means 50 years ago it probably wasn't.
And, maybe they've addressed it, but it seems a bit strange to me that NASA has used the excuse that they never went back because we did everything we needed to. So why spend tens of billions to do it now? What changed?
It's like all technologies. They start experimental and expensive, then get practical and affordable. The scale simply changes based on technology.
In the 50s, "there is a market for maybe 6 computers in the world" (famous words by IBM). In the 60s, each university wanted its own. In the 70s, two guys in a garage made one with a partially eaten fruit logo. Cars went from demonstration in the early 18th to practical in the late 19th, to mass market 30 years later. Planes were in-between.
The only reason the USA went to the moon in 1969 is because they poured ungodly amounts of money in it. Once they did the one-up-manship over the SU, the money spigot for the Moon dried up and they could no longer afford it because all the money went elsewhere. NASA would probably have loved making Lunar Base Alpha, but they didn't get the money since Congress had wised up about how much pork there was there to be had, so they had to pretend it was all part of the plan.
Refinements piled up (better electronics, better materials, cheaper fuels), and what cost a major chunk of money for the largest economy of the world has become affordable for others.
(I still remember watching the launch on a black-and-white TV set, while on vacation at the grandmother's home of friends of my parents, in the mountains of the south of France. That's among my earliest memories, I was five, almost six at the time)