A space tether is a long, strong cable that connects two objects in space, such as a satellite and a spacecraft. It can be used to transfer energy, momentum, or even materials between the two bodies. By utilizing the gravitational pull of a planet or the rotation of a celestial body, space tethers can help reduce the amount of fuel needed for propulsion, making space travel more efficient. There are different types of space tethers, including electrodynamic tethers and rotational tethers. Electrodynamic tethers generate thrust by interacting with the Earth's magnetic field, while rotational tethers use centrifugal force to maintain tension. Both types have potential applications in satellite maintenance, orbital debris removal, and even interplanetary travel.