Low-orbiting spacecraft have been observed to cause UV emission in the N2 Lyman--Birge--Hopfield bands. We examine the chemical processes expected to underlie this emission. Recombination between incident and adsorbed N atoms has been proposed as the source of radiating N*2; however, the cubic dependence of the intensity, as [N2>3 or [N2>2[O>, has not been explained. We suggest that this can be explained by a model where adsorption of nitrogen on the spacecraft surface is balanced mainly by the removal of N from the surface by atomic oxygen. On the basis of these assumptions we construct a mathematical model for the production of N*2. We show that for large enough reaction efficiencies our model predicts a magnitude and altitude dependence for the emission which can explain the measurements reported by other investigators. ¿ American Geophysical Union 1989