The earth's upper atmosphere continuously emits infrared radiation. Some of this radiation is powered by the energy stored in vibrationally excited nitrogen that can be produced by a number of exothermic processes. One of these processes is the reaction NO + N to N2 + O, in which 3.27 eV is available for vibrational and rotational energy of the N2 product as well as for kinetic energy. Once produced, the vibrationally excited nitrogen is deexcited only by collisions. In the E region, one important quenching mechanism is energy transfer to CO2, the rate for which is moderately well known. A second important deexcitation mechanism was considered to be V-T energy exchange with O(triplet P). At the start of this research program, the rate coefficients for this latter process were only known for translational temperatures far higher than are found in the earth's atmosphere. The report discusses the measurement of this rate down to as low a temperature as possible by the use of a shock tube with ozone as the source of atomic oxygen and the infrared-tracer method to monitor the vibrational energy in the nitrogen.