Research On Spacecrafts On-Oribt Servicing Mission Planning

“On Orbit Servicing(OOS)” has already become an important development direction in aerospace area,due to its remarkable value in commerce and significant potential in military.OOS mission planning is to work out the best mission scheme for the Servicing Spacecraft(SSc),satisfying all requests of the users,as well as making the most use of the resources.Aiming at developing a set of modeling and optimizing methods for OOS mission planning problems,the modeling methods and its improvement used for typical missions are studied.The main results achieved in this dissertation are summarized as follows.1 HOC mission planning model,a model of certain versatility is proposed for OOS mission planning.Based on the analysis and summary of the general OOS mission flow,it is pointed out that OOS mission is essentially a multi-spacecraft rendezvous mission,which usually consists of space rendezvous and on-orbit operation.And then a HOC mission planning model is developed on the basis of the Hybrid Optimal Control theory.This model is suitable for “one-to-many” and most “many-to-many” OOS missions.2 A set of modeling and optimizing methods is proposed for active space debris removal mission.These methods can address LEO and GEO active debris removal mission planning problems.(1)A planning method of LEO active debris removal is developed.Considering the long-duration effect of 2J perturbation and the communication constraint,taking the mission requests and characteristics into account,a HOC model is proposed,as well as the solution method.Numerical experiments verify the availability of the method,and achieve plenty of valuable outcomes,which can provide effective reference for practical application.(2)A fast scheduling method of GEO active debris removal is proposed.The scheduling of debris removal in a coplanar GEO orbit is studied.A heuristic law between the debris distribution and the best mission scheme is found out,that the optimal sequence is always the combination of the counter-orbit-wise segments in which each phase difference is larger than a certain threshold.A Rapid Method,which can achieve favourable results in short time,is presented based on this law.(3)Biobjective planning method of GEO active debris removal is proposed.The mission planning of GEO debris removal with multiple SScs is studied.The objective is to find a set of optimal planning schemes with minimum fuel cost and travel duration.A multi-objective HOC optimizaing model is presented.A modified multi-objective particle swarm optimization is employed to address the model.Numerical experiments indicate that for a definite GEO debris removal mission,that which alternative(single-SSc or multiple-SSc)is better(cost less fuel and consume less travel time)is determined by many factors.3 A set of modeling and optimizing methods is proposed for On-Orbit Refueling(OOR)mission planning.These methods can apply to Peer-to-Peer(P2P),“one-to-many” and mix refueling strategies.(1)A mission planning method for P2 P OOR is presented.The strategy that satellites exchange fuel amongst themselves in pairs is called P2 P OOR.Taking the telemetering time window constraint into consideration,a Two-level Decoupling Planning Model is established.The up-level is mission assignment,which assigns fuel-deficient satellites to fuel-sufficient satellites in optimal pairs.The low-level is time distribution,which finds the time allotted for each rendezvous segment and associated minimum total cost.Simulation verifies the effectiveness of the proposed methodology.(2)Considering complex constraints,an orbital rendezvous mission planning method is proposed and applied to P2 P OOR mission planning.Taking all phases as a whole and considering all the complex constraints(e.g.communication link,sun illumination etc.),a mathematical optimization model is established for rendezvous mission,as well as a two-stage mission planning framework.The upper stage works out a rough rendezvous path first to meet the overall requirements by using the two-body analytical propagator;while the lower stage focuses on modifying the rough path by using a high precision propagator.Afterwards,this orbital rendezvous mission planning method is applied to P2 P OOR.(3)A planning method for “one-to-many” GEO OOR mission with uncertain targets is developed.Considering three optimizing objectives,i.e.target number,task priority and fuel cost,and the uncertainty of the targets,a HOC multi-objective planning model is established for “one-to-many” GEO OOR mission.Corresponding solution method is given afterwards.Simulation analysis concludes that the proposed method can effectively address the problem;the optimizing results are influenced by the optimizing objectives and the distribution of the satellites,and these influences have their own regulations.(4)A scheduling method for mix strategy GEO OOR mission is presented.Assuming that only part of the targets can be refueled by the SSc,and the remaining targets should be refueled by the fuel-sufficient satellites.Based on the HOC mission planning model,a new model is established for the mix strategy OOR mission,and then the solution algorithm is given.Numerical experiments verify the effectiveness of the method,and analyze the good and bad points of different OOR strategies(“one-to-many”,“many-to-many” and mix).Summing up,spacecrafts OOS mission planning technology is studied in this thesis.The HOC mission planning model,which is of certain versatility,is proposed for OOS mission planning.Based on the typical application,i.e.space debris removal and on-orbit refueling mission,a series of corresponding modeling and optimizing methods are studied and proposed,which can be applied to LEO,GEO active debris removal missions and the P2 P,“one-to-many”,mix strategy OOR missions.The research work in this paper can greatly advance the spacecrafts OOS mission planning technology.Since some engineering factors are considered in this paper,the achivements can provide useful reference for practical applications.