Radiation measurements by using a ballistic range

In order to study the effect of radiation in a strong shock layer around a reentry vehicle, a ballistic range facility is used to accelerate a small plastic projectile up to higher than 5km/sec. Several optical measurements are done when the projectile passes through the test section emitting radiation from its shock layer around itself. A spectral observation is performed to find out the chemical species existing in the shock layer. The results show that the main spectra are from N2 with respect to its first and second positive bands, and several CN violet bands.