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Space elevators and tethers
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Concept using orbital mechanics to lift loads without rockets.
A cable from the equator to above geostationary altitude (about 36,000 km) could lift loads without rockets. Needs materials with huge strength-to-weight such as carbon nanotubes.
A counterweight beyond geostationary orbit keeps it taut.
Not yet feasible.
In more detail
A space elevator would be a tether from Earth's surface to a counterweight in geostationary orbit. Gravity and centrifugal forces balance along the cable, which must be extremely strong.
Real-world uses
- Space elevators are proposed as a low-cost way to reach orbit.
- Tether systems are studied for orbital debris and propulsion.
- Engineers study space elevators as a long-term way to lift cargo to orbit without rockets, using a tether anchored to the ground.
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Frequently asked questions
Is a space elevator possible?
It is an engineering challenge, requiring materials stronger than any available today.
Why geostationary?
Because the counterweight must stay above one point on Earth, so the cable is held taut.
Could a space elevator be built now?
Not with current materials. It would need a very strong, light tether, which is beyond present technology.
Related topics in Gravitation & Orbits
Equivalence principle · Orbital precession · Galaxy and cosmic structure · Gravity on other planets · Spacecraft launch energy