RESULTS OF REFERENCE LONG-TERM SIMULATIONS FOCUSSING ON PASSIVE MEANS TO REDUCE THE IMPACT OF SPACE DEBRIS

Long-term simulations of the space debris environment show an increase in the number of debris objects in low Earth orbit region. Over the next one hundred years, fragments from collisions and/or explosions are expected to become the dominant part of the debris population. Developing remediation measures for space debris is part of on-going research. Long-term simulations act as evaluation framework for understanding the effects on the space debris environment. The paper presents first the results of a comparison of two simulation codes on the basis of simple validation scenarios, which show a high level of conformance. In a second section, the paper presents a set of scenarios for the evolution of the debris population from LEO to GEO with the aim to single out and highlight the driving factors of the future environment evolution. Amongst others, the scenarios include an approach where the collision algorithm distinguishes between the main part of the spacecraft and the appendage, and generates less debris in case the appendage is hit. Despite the positive reducing effect of mitigation measures, the results of all scenarios show an increase of number of objects in the LEO region. Furthermore, we present an evaluation of the last state of an object about to re-enter Earth's atmosphere. The according orbital elements are recorded during the simulations and the information is then used for characterizing re-entry conditions. It serves as input for the design for demise approach, which aims to define predetermined breaking points in the structure of spacecraft and thus, limits the risk of space debris surviving re-entry.