A 100 km high tower is erected on a pole, e.g., the north pole. A Sling mounted on top of the tower rotates about a vertical axis. (The axis of sling rotation will precess unless the tower is erected on a pole.) The minimum mass of a steel sling (for 1-ton cargo) is greater than the mass of the Earth! Sling made of a high-strength plastic would be vulnerable to space radiation and thermal fatigue. Perhaps the best material for the sling is a rope made of strong (6.5GPa) carbon fibers coated with a thin layer of aluminum and fused together in a hot press. No bibliography. Jerome Pearson proposed this idea.

Sling on tower