Atmospheric drag on artificial satellites

Abstract

By using observed values of dP/dt and a convenient model to represent the variable density (ρ) and the scale height (H) of the atmosphere, we calculate mean values for the effective cross-section (S) of a non-spherical satellite at every day during a period of about two and half months. For that calculation we assume in advance that the satellite tumbles around an axis perpendicular to the longest axis of symmetry. For Satellite 1958 Epsilon (Explorer IV) the orientation of the axis of rotation has been determinated by an analysis of the variation in intensity of the measured radio-transmission from the satellite (Naumann,196l). A similar analysis has been carried out for the rocket of Sputnik III (Satellite 1958 δ1) based on its variations of visual brightness (Notni and Oleak,1959). Our results on the effective drag area show a good agreement with those obtained from both analysis.