N 2 spacecraft glows from N( 4S) recombination

The N ₂ Lyman-Birge-Hopfield band is the only N ₂ band system which has been identified in spacecraft glow. These bands are thought to arise from the recombination of N( ⁴S) atoms on the spacecraft surface. The absence of band systems such as the 1PG normally observed in laboratory afterglows resulting from N( ⁴S) recombination is attributed to the higher N atom kinetic energy in the spacecraft case. A brief review of the processes for the initial population the radiating states in laboratory afterglows is presented. Extensions of these processes to the N atom energies that occur in spacecraft recombination are employed to suggest the emission of other band systems that may (or may not) be expected.