4 ideas
A cable can hang from Earth's equator to space if its center of mass sits above geostationary altitude, where orbital period matches Earth's rotation. Below that point gravity pulls the cable down, and above it centrifugal effect pulls outward, so a counterweight beyond geostationary orbit keeps the whole structure in tension and stationary over one spot on the ground.
Tension in the cable peaks at geostationary altitude, so the cable must taper, thickest there and thinnest at the ends. The required taper ratio grows exponentially as the material's strength-to-density ratio falls, so with ordinary materials the cable would be impossibly massive. The elevator is therefore a materials-science problem before it is a construction problem.
An orbital cable cannot be raised from the ground. At every stage the construction sequence has to keep the partial structure in equilibrium.
Rob Merlin, an engineer famous for record-breaking suspension bridges, is recruited by the ruthless tycoon Darius Regulo to build the first cable from Earth to orbit. Merlin tackles the problem by designing an automated spinning machine, modelled on how spiders extrude silk, that produces the tapered cable in space. The novel treats the elevator as a scaled-up suspension bridge whose real obstacles are materials, dynamics and the motives of its financier.