Well, where to begin? Colonisation of space is the dream of many, but it isn’t exactly easy. There are hundreds of problems, the main one being how to get up there.
The Space plane and other “Shuttle-U-Haul” systems are frankly wanting, as they aren’t ever going to be capable of getting all the way into a decent orbit without a huge extra fuel tank and boosters, if they take off vertically, and if they try to use the atmosphere to help them, they are generally even worse off. I have a novel solution, but am currently checking into the patent scene, so I won’t be putting them here just yet!
SSTO, or Single-Stage-To-Orbit, is also a right pain, due to the sheer amount of dead weight you need to carry so the whole craft gets into orbit.
Multi-stage is, pretty much, the way to go. Burn it and chuck it. Or, like the clever British chap who now holds the patents on a new rocket system “Burn it all!”.
It is hard to think that no-one has invented the magnetic drive, or anything like that yet, so they don’t help.
A novel idea is to launch from underwater, so the added buoyancy of the craft helps you boost your initial speed while you are at your heaviest, and therefore get the biggest gain for the work you do.
Another novel idea is to use an electromagnetic railgun or linear accelerator to allow the ship to be fired at high speed before the motors and thrust system are fired. This would allow perhaps a ten percent reduction in overall mass, or more, if the more ambitious systems are used, some of which are “space elevators” or “tethers”, as envisaged by the likes of Arthur C. Clarke.