Practically all the nuclear propulsion designs are ideally launched from space. You want to get the "fallout" as far from the Allen Belts as you can from what I remember reading of General Atomics's Project Orion.
Since nuclear rockets are far more practical for all major interplanetary travel, that's why a moon base or captured asteroid habitat will be the first real step to a "space civ".
Of course I'm nutso enough to think that SpaceX should launch antimatter collection arrays in orbit to grab it from the solar wind, right now.
Getting to Mars otherwise is really just a big marketing exercise.
It now kinda seems unrealistic that most sci fi interstellar empires have lots of planet based settlements (well, the ones that have to deal with gravity). Gravity wells are a huge PITA once a reasonably closed-loop space civ gets moving. A nice asteroid belt seems a lot more valuable or a planet with a crapton of low-gravity moons, than a planet with 1G gravity well you have to spend millions to escape.
On the moon, you could probably setup maglev launch or assisted launch with just solar panels.
Asteroids may make up the vast majority of available system mass. Kind of hard to mine the interior of planets, so that mass is irrelevant. The asteroids are bits of broken up planet internals, right there for the taking?
Since nuclear rockets are far more practical for all major interplanetary travel, that's why a moon base or captured asteroid habitat will be the first real step to a "space civ".
Of course I'm nutso enough to think that SpaceX should launch antimatter collection arrays in orbit to grab it from the solar wind, right now.
Getting to Mars otherwise is really just a big marketing exercise.
It now kinda seems unrealistic that most sci fi interstellar empires have lots of planet based settlements (well, the ones that have to deal with gravity). Gravity wells are a huge PITA once a reasonably closed-loop space civ gets moving. A nice asteroid belt seems a lot more valuable or a planet with a crapton of low-gravity moons, than a planet with 1G gravity well you have to spend millions to escape.
On the moon, you could probably setup maglev launch or assisted launch with just solar panels.
Alas, our delicate earth-adapted physiology.