NRLMSIS 2.1 Error in Drag Estimation During Geomagnetic Storms of the GRACE-FO Satellite

For proper collision avoidance prediction, life estimation and orbit degradation prediction, accurate atmospheric density prediction is critical for ensuring proper drag estimation especially in Low Earth Orbits (LEO) and Very Low Earth Orbit (VLEO).This study conducts an analysis of the error on the commonly used NRLMSIS 2.1 model, by observing and quantifying the accuracy of the NRLMSIS 2.1 model before, during and following geomagnetic storms. Determining the extent to which drag models such as NRLMSIS2.1 are affected by geomagnetic storms, this paper hopes to ensure the field of astrodynamics and space flight mechanics can proceed with models that can accurately predict the information required to make correct astrodynamics assessments.