Space Debris Environment Modeling Research Based On Historical Orbital Data

Space debris environment modeling is a complicated and comprehensive engineering project, which is a problem must be studied to ensure the safe operation of on-orbit spacecraft, maintenance space security in our country and protect space environment at the same time. In this paper, the key technical problems of modeling space debris environment were studied based on historical orbital data, and the error propagation of observation data was analyzed. The main achievements are summarized as follows:Studied initial error propagation of elliptical orbit based on T-H equation. The orbital prediction error can be seen as relative motion between the true state and predict state of one space object, the theory of relative motion was introduced to study the characteristic of error propagation. The explicit function of error propagation was deduced based on T-H equation, which is suitable for both circular orbit and elliptical orbit, with which we obtained the initial error propagation law in circular orbit and elliptical orbit. And the non-gaussian characteristic of elliptical orbit perigee was analyzed and corrected.Determined the sche me of equal-area spatial partition and the rule to numbering spatial unit. Established a mathematical model to divide the space area into equal acreage, and made a detailed instruction of the rule to numbering spatial unit combined with the plan of equal-area spatial partition which was adopted in this paper, then designed the data structure to store spatial information.Studied the spatial density model and calculation method of space debris. Under the assumption that the distribution law of the space debris’ location about height, latitude and longitude were mutual independence, established the spatial density function and obtained the stay probability function about altitude, latitude and longitude. According to the engineering application, developed a simplification form of spatial density function. Made a simulation case to validate the LEO and GEO’s space density, the results consistent with the MASTER2005’s results.Studied the collision flux model and calculation method of space debris. Collision flux of space debris is the statistics of impact number between target orbit and space debris in a running cycle. First, studied the method to calculate collision flux within a single space unit, and then extended to the whole target orbit’s collision flux. Then analyzed the collision geometry between target spacecraft and space debris at local level coordinate, obtained the calculation formula of impact azimuth. Made a simulation case to calculate collision flux of International Space Station on LEO and Galaxy-11 Communication Satellite on GEO.Studied the application of space debris collision flux. The distribution law of space debris’ actual position was studied based on T-H equation, the conclusion came out that the actual position distributed in the error ellipsoid whose center is the forecast position. Made a short-term forecast to the instantaneous distribution of space debris in the future, confirmed the feasibility of T-H equation with which to predict the satellite orbit. Made a detailed analysis to the influence of America and Russia satellite collision event on LEO space debris environment, which is validation of the space debris environment model.