Modelling the reusable space transport system for small payloads delivery

Abstract

The problem of delivering a payload from orbit without the consumption of jet fuel is considered. To solve this problem, it is proposed to use a reusable space transport system that consists of a satellite in a circular orbit, a weightless tether, a capsule with a payload, and a lower module. The purpose of the paper is to develop a mathematical model of the transport system, and to determine the system's parameters ensuring safe payload descent without entangling the tether. Equations of motion were obtained by Lagrange formalism. The capsule and the lower module were considered as rigid bodies, and the friction force between the capsule and the tether was taken into account. Numerical simulation showed that when the capsule approaches the lower end of the tether, the tether segment under the capsule can transfer into rotation. In turn, this will cause the capsule to stop and entangle the tether. The influence of the mass of the lower module on the dynamics of the system was investigated. The dependence of the entanglement point position on the mass of the module was identified. For safe descent from orbit, the separation of the capsule must occur before it reaches this dangerous point.