Microblog Memes

Space travel is not the same.

Strictly considering low earth orbit, one needs to accelerate a payload to 25,000 km/h and like 500km above the ground. This is not computation or atmospheric flight. There's no shortcut, no engineering to work out, the physics dictates this is a hard problem. Solutions:

• You go up with a chemical rocket, where almost all the launch mass is fuel. To get the ratio in your head, think the liquid in a coke can vs the can that holds it... that's the mass/fuel ratio we're dealing with, and tricks like hybrid engines or booster returns barely soften the MASSIVE cost for even the tiniest things you send up.

• You assist it from the ground. "Gun" launches, as some are developing (and that I'm quite enthusiastic about), can't launch humans. Stratolaunches (from planes) only get you partway there, more like a booster.

• You go nuclear. This is the only way to increase energy density vs. chemical rockets enough to make a difference. Needless to say, there are significant environmental/safety concerns when doing this on the ground, and I'm as pro-nuclear as anyone you'll find. Check out Atomic Rockets for more on this, with concrete theoretical designs that are still batshit crazy: https://projectrho.com/public_html/rocket/engineintro.php

• You develop a space elevator or some analogue. No commercial launch research is even pretending to develop this, and it would require massive materials science breakthroughs.

...That's it. That's how you get to space. This isn't a "Wright Brothers vs modern jets" thing, that kind of cost optimization is just not physically possible. And whenever Musk lies through his teeth about practically colonizing Mars, people need to understand that...