Animation of a futuristic space elevator, linked to an orbital ring. An orbital ring is a magnetic structure or cable that encircles the Earth, and can be placed at any orientation and altitude. It moves slightly faster than orbital velocity, so that it remains taut. Theoretically, once this infrastructure is in place, objects can be magnetically levitated above the ring, or hang from it, suspended by electromagnets, and they would stay in place relative to the ground (if the orbital ring is above the Earth's equator.) A cable could be suspended from this, allowing vehicles to ascend and descend. This animation shows the base station of one such elevator. The vertical 'sky trains' each have twenty individual 'carriages' which in turn each have three levels. Moving at 150 km per hour they could reach the ring in as little as two hours.