That all skips the interesting middle values of the problem parameters :) . Seriously, for long time already it's not a rocket science. Existing technologies

That all skips the interesting middle values of the problem parameters :) . Seriously, for long time already it's not a rocket science. Existing technologies - with engineering efforts - are capable to bring humans to any point between Mercury and asteroids. We'll likely develop something better, and Solar system would be all reachable without major breakthroughs. Certainly not of the kind "rocket fins on Earth, tip on Mars".