Collision risk prediction for constellation operators
Résumé
INDEMN is an object-oriented Python program dedicated to the modeling of the evolution of the densities of space objects. Following the work achieved by G. L. Somma (IAC 2016), the dynamical model is based on a source and sink approach for various altitudes. The source terms represent the future launches, the explosion of intact spacecrafts, and the collision between objects. Different collision cross sections are used for the various types of objects and the number of debris generated is based on the NASA break-up model. The sink terms are the drag and the end-of-life de-orbitation for the satellites launched after 2009, with a controllable success rate. The code was validated using the benchmark released by the Inter-Agency Space Debris Coordination Committee on the Stability of the Future LEO environment (IADC-12-08, Rev. 1, 2013). In addition to the classical object types featured in several statistical codes, which are intact objects, explosion debris, and collision debris, a new type representing the satellites of a specific constellation is included. These satellites orbit with altitudes close to 1 200 km and they can perform collision avoidance maneuvers as long as they are fully operational. It is shown that if only one primary collision occurs, the risk of a collision involving a constellation satellite becomes larger than 5% by 2035, which highly jeopardizes the satellite constellation as a whole.