Developed and delivered a two-temperature, 17-species CO2-N2 gas model for planetary atmospheres in the gdtk-uq/gdtk repository, targeting more realistic simulations of gas dynamics for Mars and Venus environments. The work involved defining species, constructing a detailed reaction network, and implementing energy exchange mechanisms based on established models by Park et al. for both Mars and Venus atmospheric conditions. Utilizing Fortran and leveraging expertise in atmospheric modeling and chemical kinetics, the new model expanded the repository’s capabilities to support complex, multi-species gas simulations. This contribution addressed the need for accurate planetary atmosphere modeling without introducing bug fixes during the period.