Our current method of reaching beyond the womb of Earth is by chemical rockets, a method that currently requires approximately 95% of the vessel to be fuel. With this expensive method of travel, it is no wonder that humanity has yet to reach towards the stars in a significant way. The efficiency problems of spaceships propelled by chemical rockets seem as insurmountable as they are wasteful. Fortunately, humanity's ingenuity is not limited to chemicals. There are indeed feasible methods, and by this phase we will have the Aquarius colonies to provide the power.
To reach space, one only needs to achieve the correct speed. Of course the atmosphere creates some challenges, but by having a launch point on a mountain taller than 5600m, the denser half of the atmosphere is bypassed. A mountain launch is inherently inflexible; restricting the location items can be launched to. This is the benefit of an ocean-based launch tube. Trading atmosphere for flexibility, this set-up could be swivelled to point in any direction.
To utilize the speed generated by the spin of the Earth, the ideal mountain for a land-based launch would be along the equator - Mt. Kilimanjaro, Mt Cayambe, and Cotopaxi all fit these requirements. Locations for ocean-based launch sites along the equator are abundant.
Items would be launched by either magnetic propulsion or compressed gas through a vacuum tube. To further reduce friction, magnetic levitation could be used. If land-based, the tunnel will start horizontally and curve up the mountain, emerging from the peak. If ocean-based, the tube will be straight, floating at an angle in the ocean.
Utilizing compressed hyrogen gas and an ocean-based launching system, Quicklaunch has made the greatest advancements in developing a workable mass launcher.
Due to the rapid accelerations of the launch system, human survival is a concern. Non-living matter, on the other hand, has no such issues with high g-forces. We will utilize the mass launcher to transport materials up to the developing space colonies. The transportation of humans may require a more elegant approach.
To assist in the transportation of humans, a beam of light and a block of ice will be used. An array of land-based lasers will target the ice mounted on the launch capsule, flashing it to steam at 10,000°C. The superheated expansion of steam will create enough thrust to carry the ship into orbit. With this method we will move from having a spacecraft with a payload-to-fuel ration of 1-25, to a ratio of 5-to-2. Instead of expelling dozens of tons of pollution per launch, we will release a few tons of water vapour.
To further the efficiency of this approach, the space craft can first be lifted high into the atmosphere by glorified helium balloons or other such aircraft. Using advanced GPS tracking, the high elevation will pose little targeting difficulty for the laser array located far below on the surface of the Earth.
If a cable is extended far enough into the atmosphere, the centrifugal force caused by the spin of the Earth will eventually overcome gravity, holding the cable in place. Once set up, mechanical lifters would climb up and down the cable, ferrying humans and cargo to space and back. At the moment no material is strong enough to withstand the forces exerted by such a set-up. This, however, is merely a technical problem, and will eventually be solved. Currently advancements in carbon nanotubes show promising results.