>>98349
Serious answer: if humanity becomes an interplanetary species, it isn't the West that will do it, not with the current culture. The US might have done it had certain technological achievements or insights appeared prior to around 1955. Now we're too risk-averse, too squeamish, too comfortable with managed decline.
Go lookup the Zubrin nuclear salt water reactor. We could build them today. Full stop. It's completely feasible and would have fit perfectly into Chesley Bonestell's illustrated version of Willy Ley's "The Conquest of Space" that so many Boomers still have on their coffee tables. Will we? No. It's nucular. It's scurry. We'd have to spend money on it that we already plan to use babysitting Paco, Jamal, and Pajeet.
Russia isn't going to do it. They're in a demographic death-spiral and en route to complete collapse in the near term, worse than 1917, worse than 1991. China? China has always looked inward, not outward. The CCP's ideal future is hive-cities right here on Earth, filled with genetically engineered posthuman bugman slaves content to live in ze pod, eat ze bugs, devote their lives to enriching them then die quietly without making a fuss. I also rather strongly suspect that China's much-ballyhooed meteoric ascent is 98% smoke and mirrors, that their population figures and GDP are both a fraction of what are claimed, but everyone in their government pretends to believe it and passes inflated figures for everything up and down the chain because failure to go along enthusiastically could cause Party members to lose face, which would result in somebody getting disappeared at 2am by a Ministry for State Security black-bag team. The uncs among us may recall the Japanese "bubble economy" of forty years ago, which they managed just with fear of public social shaming, without even an Orwellian 24/7/365 total surveillance totalitarian police state that literally kills people for questioning it. China has been "ten years from superpower status" and a seat at the big kids' table since the Great Leap Forward and isn't far behind Russia on the path to collapse.
We aren't willing to do it. Western Europe imploded thirty years ago. Russia can't. China can't and doesn't even have the cultural drives that'd make them contemplate the idea for a quarter of a second. Japan's population is aging rapidly and much more interested in other things. India? Wait, you're serious. I'll laugh harder. That leaves approximately nobody with the drive and resources to pursue the project, barring a yuge geopolitical shakeup and every applecart getting not just overturned but blasted to atoms.
https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket
https://www.projectrho.com/public_html/rocket/enginelist2.php#nswr
https://www.npl.washington.edu/AV/altvw56.html
For the curious. The tl;dr is, imagine a large-ish, on the order of tens of meters in diameter, hollow incomplete sphere lined with a heat-resistant material that reflects neutrons, like maybe tungsten carbide. The sphere is the reaction chamber. One side of it, which we'll call the bottom, has a rocket nozzle sticking out of it. The other, which we'll call the top, has tubes going in that bring in a liquid fuel. This isn't just any rocket fuel. It's soluble uranium salts, like maybe uranium tetrabromide, dissolved in water, with a high level of fissile isotopes like U235 or maybe U233. The concentration of dissolved uranium and the volume and shape of the reaction chamber are designed very carefully so that you get a chain reaction when the chamber is not quite full of fuel; fuel tanks are long and skinny so that a critical mass doesn't form until the fuel is in the reactor. Anyway, when sufficient fuel is in the reactor, a chain reaction takes place. In a millisecond the water mixture flashes over to steam, then plasma, and squirts through the nozzle as a roostertail of radioactive fire going that-a-way at, if you believe Zubrin's back-of-the-envelope calculations, around fifty kilometers a second. That's-a spicy-a meatball! Specific impulse, the number that the rocket scientists call Iₛₚ, is yuge for this system and makes any and all chemical rocket fuels, even the weird exotic ones that use crazy dangerous stuff like chlorine trifluoride as the oxidizer, look pointless.
It is for real. It is legit. Dr. Zubrin is the real deal. And if he'd been born seventy or eighty years earlier, I'm sure President Eisenhower and Admiral Heinlein would have the Navy building "atomic blast engine" space battleships before cars had tailfins. Americans could have been prospecting the asteroid belt for rare heavy metals before 1965. But he wasn't. And they didn't. And Americans have been conditioned from birth since the 1970s to hear the word "nuclear" and start screaming and flailing hysterically like children with Down's Syndrome on a school trip to visit an abattoir. Who will come after us, who'll pick up the King's crown from the gutter to put it on their own heads like Napoleon? Will anyone? Spoiler: no
