The Orbit Maneuvers for Spacecraft reentry with Full Parameters

In order to send the spacecraft to return to the scheduled placement accurately in accordance with the nomina 1 trajectory, three orbital maneuvers can control the spacecraft to the nominal reentry point with fully-parametric position and velocity including six reentry-point parameters of height, longitude, latitude, velocity value, velocity inclination, velocity azimuth to meet requirements. Three orbit maneuvers are non-redundant accurate reentry trajectory controls to achieve the reentry point with fully-parametric position and velocity. Affected with orbit perturbation model error, orbit determination error, orbit control error, etc. the reentry-point status will deviate from the theory status after a longer flight. Moreover, with the implementation of orbit maneuvers one by one, orbit maneuver programming variables decrease. Under the conditions of the various errors and the orbit maneuver variables reducing, to solve the technical problems of the spacecraft landing at the predetermined placement with the multi-parameter optimization reentry point, the fully-parametric reentry trajectory control strategy need to be adjusted dynamically. This paper designs three orbital maneuvers control mode ls and algorithms to achieve spacecraft accurate reentry point with fully-parametric position and velocity. For the reentry point of fully-parametric position and velocity objective requirements, the relationships of the maneuver programming variables in match with the objective reentry point parameters are established, and the orbit maneuver initial values are solved for the reentry position vector and velocity vector independently. A gradual orbit maneuver programming strategy is established with the main constraint to the velocity vector, the supplement constraint to the position vector. The performance indicators are designed to solve globa 1 optimization and local optimization solution, and differential correction iterative algorithm is achieved to solve a series of orbit maneuvers in whole. The error analysis model of the spacecraft reentry point fully-parametric position, velocity reentry is establishe d, and the reentry point error states are analyzed with the orbital perturbation parameter error, orbit determination error, orbit control error and other factors.