Increased concentrations of green houses gasses results in warming of the lower atmosphere and cooling of the upper atmosphere. Cooling of the upper atmosphere results in an increased density of oxygen atom, a reactive diradical and the dominant species in the upper atmosphere. Space vehicles, traveling at a high rate of speed, collide very energetically with the reactive oxygen atom resulting in aerodynamic drag and chemical reactions. The work discussed in this seminar explores how computational methods can be used to model chemical reactions involving oxygen atom. The talk will give an overview of the motivation for the work, a discussion of the computational resources, and how these resources are used both to calculated chemical energies and also the kinetics of the reactions.