Near ultraviolet radiation during space vehicle entry into Earth atmosphere

A method is presented for calculation of nonequilibrium radiation spectrum in band systems of electronic transitions in diatomic molecules from plasma structures around space vehicles moving in the Earth atmosphere with hypersonic velocity. The method is based on numerical solution of the three-dimensional Euler equations for a nonequilibrium mixture of chemically reacting gases augmented with conservation equations for electronically excited states of molecules. As an example nonequilibrium radiation is calculated in near ultraviolet $\lambda=230\text{--}380$ nm from the shock layer on the windward side of the reentry vehicle (RV) “Soyuz-TM” along entry trajectory into the Earth atmosphere in the altitude range 45–70 km. Satisfactory agreement is obtained with a flight experiment on radiation observation during the entry of RV “Soyuz-TM” on board the International Space Station.