RE-ENTRY ANALYSIS COMPARISON WITH DIFFERENT SOLAR ACTIVITY MODELS OF SPENT UPPER STAGE USING ESA’S DRAMA TOOL

Kurzfassung

The goal of the paper is to investigate the influence of di�erent methods for solar activity forecasts on the simulation of residual lifetime of upper stages in GTO. For this study the OSCAR software from the ESA DRAMA tool suite was used to perform an orbital decay simulation for an Ariane 4 upper stage (1997-016-C) from 1997 to 2012. As a reference, the orbital decay of the rocket body has been compared to TLE data available from Space-Track. For the simulation, it was possible to select between a best-guess scenario (including best case and worst case scenarios), constant equivalent solar activity, ECSS standard cycle or any user-selected historic cycle and solar activity sampled through a Monte Carlo approach. In addition, the evolution of the orbit has been analysed taking orbit perturbation into account (Drag, Geopotential, Third Bodies e�ect). Finally a sensitivity on the mass and cross-section area of the upper-stage have been performed in order to understand which parameter may influence the residual life in GTO.