Dynamics of Robotic GEostationary orbit Restorer system during deorbiting

With the development of human space activities, the number of spacecraft in geostationary orbit (GEO) has increased dramatically. According to the European Space Agency (ESA), by the end of 2008, there were 1186 objects in GEO of which only 32% were controlled operational satellites [1]. In the GEO, there are also many malfunctioning or abandoned spacecraft and lots of space debris that need to be deorbited [2] orbiting alongside functioning spacecraft. It has become necessary to monitor and deorbit these uncontrolled spacecraft and space debris to afford a safe environment for operational spacecraft so that collisions can be avoided. To do this, several alternatives have been proposed by scholars and aerospace research institutions all over the world. Among the suggestions are the RObotic GEostationary orbit Restorer (ROGER) for orbital monitoring and deorbiting [3, 4], an ion beam shepherd for contactless space debris removal [5], electrodynamic tether deorbiting [6-8], deorbiting using solar radiation force [9-11], and space robots. [12, 13]