Covert Maneuvering Orbit Design For GEO Spacecraft

The United States and other countries are developing space surveillance system.Spacecrafts,from space stations to small satellites,are all exposed to the system.The surveillance system allows them to track and catalogue the space targets.The security of the spacecraft is threatened.It is difficult to keep secrets and adversely affect the national economic interests,political interests,especially military interests.This problem has attracted attention in the aerospace industry and has led to the development of satellite stealth technology.However,due to the slow progress of key technologies and economic costs,the technology has not been practiced.This paper proposes a unique approach to this problem from the point of orbit design,in order to achieve the penetration of the space surveillance system with a small cost and achieve the concealment of space missions.The geostationary orbit(GEO)orbit is important orbital resource.The monitoring of the orbiting spacecraft by the surveillance system means that the system and motion states are exposed,which causes great trouble for the spacecraft.Aiming at this problem,this paper studies the covert orbit design for spacecraft on GEO orbit.The method of modeling the optical surveillance system,the covert maneuvering orbit optimization design method and the hidden trajectory design method utilizing the Earth shadow are studied,and a set of hidden trajectory design methods for different situations are formed.Firstly,the problem of modeling the visibility for GEO orbit by optical surveillance system is studied.Based on the constraints of earth occultation,ground shadow,sunlight interference,and field of view,the visibility model of optical monitoring is established.The solution of the model is simplified to a multi-constraint solving problem.The simulation results show that the current space surveillance system has a large gap for high-orbit space monitoring,which provides a prerequisite for the design of covert maneuvering trace.Then,the design of spacecraft’s hidden concealed maneuvering trajectory is studied.Aiming at the various types of surveillance systems for GEO orbits,based on the multi-pulse rendezvous model of spacecraft,a design method of spacecraft covert maneuvering trajectory is proposed.Firstly,the convert trajectory design optimization model is established.The requirement that satellite is not monitored during maneuvering is converted to the real-time path constraint during the spacecraft maneuver.A penalty function is designed to handle this path constraint.The model was optimized using a differential evolution algorithm.The simulation demonstrates the effectiveness of the method.The spacecraft avoids monitor by changing the orbital inclination to achieve concealed maneuver.The covert orbit of the spacecraft is greatly affected by the ground station and low-orbit satellite monitoring,but is less affected by the high-orbit monitoring satellite.When the number of sensors in the surveillance system increases,the gap in space surveillance is reduced,and the design of the covert trajectory becomes difficult.Finally,the hidden trajectory design method using ground shadow is studied.The ground shadow constraint is the inherent constraint in optical observation.This law provides a method for covert maneuver of spacecraft,that is,using the ground shadow in space to avoid monitoring and realize the covert maneuver of spacecraft.A step-by-step reverse path planning strategy is proposed.The mission process is divided into two parts: phase modulation segment and covert maneuver segment.According to the time-reverse sequence of the task,the ground shadow interval,covert maneuver trajectory and phase modulation strategy are designed.The results verify the effectiveness of the method and the method error is analyzed.Focus on the problem of GEO orbiting spacecraft being monitored,the paper first proposed a complete series of methods for initiative covert orbit maneuvering.This method can put forward different solutions for covert maneuvering for various surveillance system and provides a solution for spacecraft stealth.