Space elevator construction

Three basic approaches for constructing a space elevator have been proposed: First, using in-space resources to manufacture the whole cable in space. Second, launching and deploying a first seed cable and successively reinforcing the seed cable by additional cables, transported by climbers. Third, spooling two cables down and then connecting the ends, forming a loop. Three basic approaches for constructing a space elevator have been proposed: First, using in-space resources to manufacture the whole cable in space. Second, launching and deploying a first seed cable and successively reinforcing the seed cable by additional cables, transported by climbers. Third, spooling two cables down and then connecting the ends, forming a loop. There are two approaches to constructing a space elevator. Either the cable is manufactured in space or it is launched into space and gradually reinforced by additional cables, transported by climbers into space. Manufacturing the cable in space could be done in principle by using an asteroid or Near-Earth object. One early plan involved lifting the entire mass of the elevator into geostationary orbit, and lowering one cable downwards towards the Earth's surface while simultaneously another cable is deployed upwards directly away from the Earth's surface. Tidal forces (gravity and centrifugal force) would naturally pull the cables directly towards and directly away from the Earth and keep the elevator balanced around geostationary orbit. As the cable is deployed, Coriolis forces would pull the upper portion of the cable somewhat to the West and the lower portion of the cable somewhat to the East; this effect can be controlled by varying the deployment speed. However, this approach requires lifting hundreds or even thousands of tons on conventional rockets, an expensive proposition. Bradley C. Edwards, former Director of Research for the Institute for Scientific Research (ISR), based in Fairmont, West Virginia proposed that, if nanotubes with sufficient strength could be made in bulk, a space elevator could be built in little more than a decade, rather than the far future. He proposed that a single hair-like 20-ton 'seed' cable be deployed in the traditional way, giving a very lightweight elevator with very little lifting capacity. Then, progressively heavier cables would be pulled up from the ground along it, repeatedly strengthening it until the elevator reaches the required mass and strength. This is much the same technique used to build suspension bridges. The length of this cable is 35,786 km or 35,786,000 m. A 20-ton cable would weigh about 1.12 grams per m.