Space Elevator Stability.pdf

Acta Astronautica 62 (2008) 514–520 /locate/actaastro Space Elevator: Stability Lubos Perek?,1 Astronomical Institute, Czech Academy of Sciences, Prague, Czech Republic Received 22 December 2006; received in revised form 14 January 2008; accepted 17 January 2008 Available online 6 March 2008 Abstract Many papers have been published on engineering and economic aspects of the Space Elevator. The Elevator, however, is a very special and unusual astronomical body. Its behavior in space is affected not only by the attraction of the Earth and by the “centrifugal force” but also by the attraction of the Sun and the Moon, by the detailed shape of the Earth, by the presence of space debris, etc. Not all of the minor effects have been adequately studied. The size of the Space Elevator and its lack of resistance against buckling or bending require a detailed study of its stability, both in its initial phase as a geostationary (GEO) satellite as well as in its operational phase as a “sling”. Lunisolar perturbations and other minor forces may affect the stability in the initial phase and will cause oscillations in the operational phase. Station- keeping thrusters will have to be mounted at selected points along the cable in order to maintain stability. In addition, the thrusters will perform local maneuvers for avoiding collisions with passing space debris. The control system of thrusters has to be adaptive, reacting fast to actual situation and rectifying the attitude of the Elevator whenever necessary. A further advantage of the thrusters is a possibility to locate the Elevator at any longitude, possibly looking for a region with minimum traffic at GEO distance. Extensive numerical simulations will have to be performed in order to determine elements of the thrusters and their control system. ? 2008 Published by Elsevier Ltd. 1. Introduction The idea of building a Space Elevator has been made well known and popular by Arthur C. Clarke in his book “The Fountains of Paradise”. Wi