Orbital maneuvers using space tethers

Abstract

The present paper has the goal of studying how to make impulsive orbital maneuvers in a system formed by two satellites using space tethers. The idea is to connect those two satellites by a tether, put them in a rotational motion and then cut the tether in the right moment. A simplified mathematical model is developed for the movement of this system, because the effects depend only on the osculating orbits before and after the tether cutting. Other effects of the dynamics are only important to find the correct time to make the tether cutting, but do not influence the orbits for the satellites after the separation. Therefore, the system is composed by two artificial satellites that move around the Earth connected by a tether in an initial circular orbit and that rotates around their center of mass with variable angular velocity. The goal is to find the conditions (tether length and instantaneous angular velocity of the system) that make one of the spacecraft to escape from Earth and the other one to collide with the Earth. This is an important technique to remove satellites from orbit after their end of life for Low Earth Satellites.