Reply To: I need to know what to do

[Jolly Roger]

JoeL wrote: The main Space Fountain (and related concepts) stumbling block that hasn’t been addressed is that whatever reduction in weight {that} is experienced by the structure will be experienced as a downwards force on whatever turns the pellets around.

You seem to be assuming that the entire weight of the structure is supported by the top deflector station. That will not be the case. “Lifting Stations” will be positioned at regular intervals up the pellet stream. These will be pellet decelerators, and momentum will be transferred from the pellet stream to the lifting stations. A section of vacuum tube will be suspended from the lifting station above it. Each lifting station will only be responsible for lifting the weight of the section of vacuum tube between itself and the one below it.

Sections of vacuum tube will be loosely connected in some sort of sealed sliding arrangement that allows a little relative movement of lifting stations and tube sections.

Other structures, such as walls, elevators, etc. will be attached to lifting stations.

… a vertical underground shaft deep enough to effect a manageable rate of change in momentum would probably penetrate into the earth’s mantle.

You seem to be assuming that the base decelerator has to be linear. Current designs assume that the pellet path can be bent 90 degrees.