The Atmosphere Explorer (AE) satellites have acquired a large data base of aeronomic parameters measured over a wide range of geophysical conditions over the past 3 years. These data have already been used in a straightforward way to determine rate coefficients for many thermospheric reactions. In this paper we report the use of the AE data in a new way to simulate laboratory-type control of variables to determine the rate coefficient for the reaction O+(2D)+O&kgr;→O+(4S)+O. By appropriate selection of data we succeed in eliminating the effects of three uncertain rate coefficients on our determination; these are recombination of N2+ and electron and N2 quenching of O+(2D). We find that k<3¿10-11 cm3 s-1. This upper limit is a factor of 3 smaller than an earlier estimate of the rate coefficient made from AE data. The difference in results is attributed to a large uncertainty in the dependence of N2+ recombination on vibrational excitation which affected the earlier work. Our technique demonstrates how the atmosphere can be used successfully as a laboratory to study atomic and molecular processes.