A mathematical model of a thermionic thermal protection system has been developed to study the characteristics of heat and mass transfer in a spatial, high-enthalpy air flow around a body. The effect of electron evaporation (emission) from the emitter surface on the decrease in the temperature of the composite shell of thermionic thermal protection is estimated. The effect of different angles of attack on the heat-transfer regimes in the system of multielement thermionic thermal protection is studied. Qualitative agreement of the calculation results with the known data has been obtained.