The oxidation of a porous carbon network (FiberForm) has been studied in flow-tube experiments where the reactive gas was O2 . Unlike in pure graphitic materials, O2 diffuses easily into the porous network, causing in-depth oxidation under rarefied flow conditions because the reactivity of O2 with carbon is low . In contrast, such in-depth oxidation is unlikely to occur with a flow of atomic oxygen, because the high reactivity of O atoms will result in reactions before they have penetrated very deep . Characterization of O2-oxidized fibers using SEM showed etch pits similar to those observed in the oxidation of HOPG . Interest in graphene has prompted many experimental and numerical studies to examine the oxidation and reduction of HOPG and graphene oxide. Oxidation of HOPG by atomic oxygen has also been extensively studied to understand material degradation in low Earth orbit (LEO) . Most experimental studies of the oxidation of HOPG by atomic oxygen have been limited to moderate surface temperatures (~1000 K or below), but a recent study from our lab reported O-atom reactive scattering dynamics on HOPG at temperatures up to 2300 K . In addition, we have conducted similar experiments with vitreous carbon . Key results that were obtained from the previous studies in our laboratory on the oxidation of hot HOPG and vitreous carbon were: (1) O2 has extremely low reactivity compared with O atoms and scatters inelastically. (2) Even when incident O atoms have a very high translational energy of ~5 eV, they have a significant probability of sticking to the surface momentarily and then desorbing, and the probability of this process increases with surface temperature. (3) CO is the dominant reactive product and exhibits apparent non-Arrhenius behavior, with the flux of CO reaching a maximum and then decreasing as the surface temperature increases. (4) CO formation occurs mainly through reactions of adsorbed O, even when O atoms with very high incidence energies strike the carbon surface. The probability of CO formation is dependent on the surface coverage of O. The apparent non-Arrhenius behavior of carbon oxidation has been observed in the past . However, our work was able to explain this behavior as a competition between the thermal desorption of O and reaction to form CO .