Atomic oxygen density values in the 80-105 km altitude equatorial region have been obtained by analyzing the chemiluminescence of nitric oxide point releases from three CENTAURE II-C rockets. The light emission produced by the NO-O chemiluminous recombination was sufficiently high to render the artificial clouds observable only by ground-based instruments. The difficulties associated with these kind of experiments have been greatly avoided by a new technique ejecting the NO gas into the backward direction of the flight. It has been found that below 90 km the derived atomic oxygen densities are in relatively good agreement with those reported by other workers. At approximately 105 km the measured value is about two times higher than the n(O) density obtained by averaging a set of data from a great number of other nights but coincides rather well with the measurements of Dickinson al.