Space fountain

As known materials cannot support a static tower with this height, a space fountain has to be an active structure: A stream of pellets is accelerated upwards from a ground station.

The necessary force for this deflection supports the station at the top and payloads going up the structure.

Its largest downside is that the tower will re-enter the atmosphere if the accelerator fails and the stream stops.

[2] The lower part of a pellet stream has to be in a vacuum tube to avoid excessive drag in the atmosphere.

[3] Unlike a space elevator, this concept does not need extremely strong materials anywhere, and unlike space elevators and orbital rings, it does not need a 40,000-kilometre (25,000 mi) long structure.