I want to believe. I do. I've been a fan of space and all the science fictiony- science facty shit that entails since long before you were born. But I went to my first launch and it let me truly see the problem for the first time. Let's say Elon Musk builds his launch gun. Let's assume he builds it for free. Let's assume he's also cornered the market on solar energy such that he can sell it for 6 cents per kilowatt hour. And he's managed to get someone else to pay for the panels, too, so that's also free. Finally, let's presume that he's figured out a way to 3D-print anything he wants out of air, also for free. Our cost per kilo to LEO, presuming Zeus himself gifted Elon the whole fuckin' apparatus, is 225 kW/H x .06 = $13.50 per kilo. For starters, this hopefully illustrates what kind of prime-grade weed Elon is smoking when he says he can get Falcon Heavy launches down to $20/kilo. But it also means that lofting the 408,000 kg International Space Station is gonna cost about $5.5 million dollars. That gives you a pressurized volume of about 32,000 cubic feet, or basically a quonset hut. You can keep six people alive. For five and a half million dollars, all else being free, cheapest, most optimistic possible conditions, you can play space volleyball. Or, you could if you had two teams instead of one. But disregard that. What can you do in space that you can't do cheaper on the ground? You wanna see a depressing Wikipedia article? Here you go. It starts off with "During the Soyuz 6 mission of 1969, Russian astronauts performed the first welding experiments in space" and makes its way to "Research and development is required to determine the best commodities to be produced, and to find efficient production methods. The following products are considered prospective early candidates." Fifty fuckin' years, yo. We've been attempting to justify our presence in space for fifty fuckin' years and the best we can do is "look, insulin crystals are bigger." So the question then becomes why. WHY go to space. Okay, so that if a big fuckin' asteroid wipes out Earth we're still kickin' it on Mars. But even my Tooth Fairy Express is $14 to get a can of beans to LEO and the only justification I have to launch beans at low earth orbit is "fear of asteroids." ULA can get a Delta II up for $164m. Elon Musk puts a Falcon 9 at $62m. Go Elon! Let's put his pricing at 30% what the Bad Guys can do. So if a return manned mission to Mars is $230 billion that means that Elon can do it for $70b. And that's one mission to Mars and back, no interplanetary manufacturing capability, no waystations at the Lagrange points, nothing sexy like that. And all that sexy shit? Yeah, you need that before you're mining asteroids. I want to believe. I do. But this here gravity well is so very much deeper than most people really want to grapple with. Yeah, LEO is 90% of the way to anywhere in the universe but it's also 10 times as fast as a bullet. Bullets the size of Volkswagens require office buildings worth of high explosives to get up to speed. And if it isn't an office building worth of high explosive, it's a thunderous amount of energy some other way, and it's not going to get anywhere near cheap enough when our cost-cutting measures are things like "land the first stage." I want to believe. But the more I've learned, the harder it is.