3 ms·
Where else would you get it? Unless it's beamed in the form of light, I don't know of many options. The challenge is to get from the Earth's surface, to orbit.
by neolefty 8y ago
Where else would you get it? Unless it's beamed in the form of light, I don't know of many options.
The challenge is to get from the Earth's surface, to orbit. Yes, there's oxygen along the way, but the speeds you have to go will wreck you if you stay in the atmosphere at all. So you get into vacuum ASAP.
Once you're in orbit, you have a lot more options. For example, you don't need a high-thrust engine—instead, high-efficiency is fine, even if it's low thrust. Etc.
- dangerbird2 8y agoHe's probably implying mining or synthesizing fuel on smaller gravity wells like Mars. Being able to synthesize fuel for the return trip could massively cut back on initial launch weight. Energizing propellant with a microwave beam (https://en.wikipedia.org/wiki/Beam-powered_propulsion https://en.wikipedia.org/wiki/Beam-powered_propulsion) has been hypothesized, while a solar sail is much more realistic with modern technology.
- mrfusion 8y agoHere are just a few: Beam microwave or laser energy to ship Launch loop Sky hook Launch fountain Some company is even working on a launch slingshot. I’d provide Wikipedia links but I’m on my palm pilot. Look them up though. Interesting stuff.