Non-equatorial space elevator design approach

Abstract

The advantages of a non-equatorial space elevator have attracted the attention of several researchers. In this paper, two static tether models are presented for studying the tapering of a uniform-stress tether using a discretization method. The efficiency and accuracy of the two models are verified by comparing them with models used in other studies. We then study the range of latitudes that allowed for a uniform-stress space elevator and evaluate the influence of the anchor-point latitude on the system payload capacity. The results show that increasing the tensile strength of the tether material can expand the range of the space elevator system deployment. However, a high latitude of anchorage would greatly sacrifice the payload capacity.

Dynamics and Energy Analysis of Nonequatorial Space Elevator Using Three-Dimensional Nonlinear Finite Element Method Extended to Noninertial Coordinate System

“…Gassend [8] studied the latitudinal range applicable for nonequatorial space elevators. Subsequently, Cowan and Leonard [10] modeled the tether as rigid bar elements, and Wang et al [20] proposed a multibody-rigid-bar model and a spring-mass model with multiple degrees of freedom applicable for nonequatorial space elevators and obtained the equilibrium position. Moreover, Wang et al [21] analyzed the oscillation modes of the tether of a nonequatorial space elevator using a spring-mass model with multiple degrees of freedom.…”

“…In nonequatorial space elevators, the direction of the combined gravitational and centrifugal forces is complicated, which creates difficulty in deriving the characteristics of the tapered cross-sectional area using analytical methods. In context, Wang et al [20] proposed a numerical method to determine the tapered shape of a nonequatorial space elevator under constant stress for a rigid bar and spring-mass model. Wang et al [20] formulated the rigid bar model in a two-dimensional planar coordinate system comprising the X -Z axes.…”

“…In context, Wang et al [20] proposed a numerical method to determine the tapered shape of a nonequatorial space elevator under constant stress for a rigid bar and spring-mass model. Wang et al [20] formulated the rigid bar model in a two-dimensional planar coordinate system comprising the X -Z axes. As reported, the same gravitational and centrifugal forces can be obtained on any two-dimensional plane containing the rotation axis [8].…”

“…As indicated, the gravitational force was dominant in the region proximate to the Earth than in the GEO radius of 4.1 × 10 7 m. In contrast, the centrifugal force caused by the rotation of the Earth was dominant in the region located farther from the GEO radius. In the rigid bar model proposed by Wang et al [20], the tether is divided into rigid bar elements, and the unknowns represent the cross-sectional area of each node, magnitude and direction of the acting tension, and angle between the rigid bar and equatorial plane. The solution for these unknowns with a solver yields the tapered crosssectional area characteristics.…”

The Stability Analysis of a Tether for a Segmented Space Elevator

“…Gassend gave an approximate solution of the crosssectional area of the earth's non-equatorial space elevator [11]. Wang Established the static model of the earth's non-equatorial space elevator in 2019, found that increasing the tensile strength of the tether material can expand the deployment range of the space elevator system [12], established the dynamic equation and analyzed its vibration mode [13]. Okino proposed a new type of counterweight space elevator system.…”