In order to decrease errors associated with precision orbit determination, the U.S. Naval Research Laboratory (NRL) is developing a new atmospheric model, NRLMSIS (NRL Mass Spectrometer and Incoherent Scatter), which utilizes near-real time atmospheric data to generate a more accurate total density prediction. By integrating NRLMSIS into SpecialK, NRL's parallel processor orbit determination software, a space object's ephemeris can be generated with the refined atmospheric density as an input. This paper compares ephemerides generated by current atmospheric models used by SpecialK with results generated by SpecialK and a model similar to NRLMSIS. Although this study hoped to confirm NRL's hypothesis that NRLMSIS improves orbit determination, preliminary results are somewhat inconclusive.