Animation of a futuristic space elevator, linked to an orbital ring. Space elevators present a novel
way of getting personal and materials into orbit. Traditionally they are 'cables' tethered to the
ground and anchored to a counterweight in geostationary orbit. But this makes them 36,000 km (22.000
miles) long, and no known material can support its own weight at this length. An orbital ring uses a
different approach. A magnetic ring encircles the entire Earth, and it can be placed at any
orientation and altitude - even as low as 100 km. It moves slightly faster than orbital velocity, so
that it remains taught. 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
interior of an imaginary 'sky train' destined for an orbital ring at an altitude of 300 km. Each
train has twenty individual 'carriages' which each have three levels. Moving at 150 km per hour it
could reach the ring in as little as two hours.