A Study Of Contactless Space Debris Removal Based On Ion-beam-propelled Method

With the increasing of human space mission,there are more and more space debris in space.The increase of space debris is not only a menace to human space activities,but also makes it easier to produce more space debris when striking other spacecraft.Space debris is very difficult to be removed automatically under natural conditions,and it's going to occupy the limited orbit resources as time goes by.Now,there are lots of space debris removal methods have been presented,and the method of ion-beam-propelled has been paid attention widely because of its advantages of low cost,non-contact and safe operation.This method needs ion beam satellite to trace the space debris persistently,and to eject high-speed plasma to the space garbage.By the strike of plasma and space debris,the momentum transfers.The ion beam pushes the space debris along the tangential direction of the orbit.At the end,the space debris will be removed.This method needs to control the ion-beam satellite and the debris have the same acceleration.This article will study the characteristics of ion-beam by mathematical modeling and propose some control strategies to control the satellite.Firstly,the concept of ion-beam-propelled for contactless space debris removal is illustrated.And this article studies the influence to debris removal under the thrust of satellite.It shows that the satellite can perform a good job by employing very little fuel.Secondly,the article analysis the characteristics of ion-beam by numerical modeling.The ion beam thruster is an electric propulsion system,and it can generate ultra-high speed plasma plume.It's very important to establish a mathematical model for ion beam to study the force analysis of space debris.In this article,the Parks and Katz self-similar model is chosen in order to study the distribution of ion number density of plume,the distribution of ion velocity,and the distribution of pressure and the efficiency of momentum conversion.These job lays a foundation for the space debris control.Thirdly,a basic aspect to be investigated is the dynamical model of ion-beam satellite and space debris.In detail,this article set up a wide range of orbit maneuver model and a relative dynamic model of satellite and debris.At last,the article investigates the control of satellite when it removes the debris.There are two cases during the space debris removal.On the one hand,using the linear quadratic optimal control theory to control the satellites and space debris when the satellite is close to the debris,and the purpose is to maintain a constant position between the two objects.On the other hand,using the theory of optimal control based on Gaussian pseudo-spectral method to control the satellite for a wide range of orbit maneuver.