An electromagnetically propelled space transportation system is provided for transporting passengers and/or freight between the Earth's surface and orbiting spaceports via reusable spaceplanes. Each spaceplane is equipped with a plurality of superconducting propulsion coils extending along its fuselage and is accelerated to orbital velocities inside a vacuum tube by a 1,530 km long electromagnetic linear accelerator. The vacuum tube is evacuated by utilizing the accelerator as a giant vacuum pump wherein a free-moving, magnetically propelled, air-tight piston is driven through the entire tube at low speed thereby forcing the air directly out the end. The spaceplanes are equipped with movable wings and other aerodynamic surfaces that are retracted during launching and extended during landing. The accelerator is capable of launching spaceplanes directly to geosynchronous orbits or onto interplanetary trajectories. The accelerator is embedded deep underground with a maximum depth of 46 km and emerges near the summit of a high mountain. The system is powered by the Earth's gravitational field whereby natural hydro and geothermal energy is converted into electrical energy. Since substantially more electrical energy is generated than is used by the accelerator, the system produces vast amounts of clean renewable electrical energy.