The total and the spectral intensity of the radiation emitted by rocket combustion productsAT HIGH PRESSURE WAS STUDIED. Spectral and total radiation data are presented for 3 rocket propellant systems HNO3 and HN3 N2O4 and NH3 and N2O4 and N2H4. Each of the combinations contained H2O as the principal radiating gas. The measurements were made at a nominal combustion pressure of 700 psia. Emissivity correlations and methods of estimating the temperature of the combustion gases are developed. A technique is given for obtaining direct observation of high temperature gases inside the combustion chamber of a small rocket motor.