where e is the formation energy of one NO molecule (e = 1.515 x 10-12 erg or 0.95 eV), M is the mass of the HLLV, and V, is the entry velocity. To be consistent with the two-dimensional atmospheric model adopted in the present work, the global atmosphere was partitioned by the latitude increment of 5° and the altitude increment of 2.5 km (1.6 mi). Figure 5 shows the distribution of NO^ by altitude. The total amounts of NOj. produced per reentry, in terms of the mass equivalent of NO, and the efficiency of conversion of the initial kinetic energy into NO are given in Table 2. The efficiency values obtained here are nearly equal to those for the Space Shuttle Orbiter (28) and for large meteoroids (29). Figure 6 shows the production of NO molecules as a function of altitude and latitude for the nominal entry case (45° angle of attack). 4. THE ACCUMULATION AND DISPERSION OF ROCKET EXHAUST CONTAMINANTS The models described above have been used to simulate the accumulation and dispersion of the substances deposited during HLLV launch (water vapor, nitric
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