Application of a Six Degrees-of-Freedom Drag Model for Small Satellite Mission Development

For spacecraft in low-perigee orbits, atmospheric drag presents one of the largest uncertainties in dynamics modeling. These uncertainties are particularly relevant to small satellites, which often fly in the LEO regime and produce control forces and torques comparable in magnitude to drag. In this study, a six degrees-of-freedom orbital dynamics model with drag perturbations is developed, and several applications of the model are investigated. The model is used to evaluate differential drag dynamics for the MR and MRS SAT microsatellite pair, and the implications to collision avoidance and end-of-life procedures are discussed. Preliminary propellant usage estimates for the mission are also generated. A modified method for determining ballistic coefficient using relative satellite navigation data is introduced and compared to previous methods.