Error-Tolerant Technique For Catching a Spacecraft With a Spinning Tether

Abstract

This paper presents a novel configuration of a space system which addresses the issue of rendezvous and capture of a spacecraft in a lower (or higher) energy orbit for later injection into a higher (or lower) energy orbit. We first demonstrate that a slender long tether loop in space can maintain its shape while spinning and that the width of its opening depends on the boundary conditions of the loop arms near the center of rotation. Subsequently, we show how the tether loop could be utilized to allow a rendezvous and capture of a spacecraft approaching the loop from a lower (or higher) energy orbit while the natural target area of the loop enables an extended time opportunity for spacecraft capture which is tolerant of errors. We also discuss at the conceptual level a possible device/technique for making a soft contact between the loop and the incoming spacecraft. These results are directly applicable to spinning tether systems for space transportation from low Earth orbit to geotransfer orbit and to escape trajectory or for reentering payloads into the Earth atmosphere (from higher energy orbits) with high ΔV and a predictable reentry trajectory.