A test series was performed in the Electric Arc Shock Tube (EAST) facility with the aim of reproducing flight conditions encountered during the Mars 2020 mission entry into the Mars atmosphere. For this test series, the EAST facility was instrumented with two spectrometers for optical emission spectroscopy (OES) measurements and three mid-infrared lasers for tunable diode laser absorption spectroscopy (TDLAS). This paper focuses on the spectrally and spatially resolved radiance measured with OES. Conditions were chosen to achieve similarity to backshell radiative heating measured with the MEDLI2 heat flux gauges near and after the time of peak heating. Comparisons were made against two candidate kinetic models for Mars entry. Below [Formula: see text], the chemistry is effectively frozen, with measurements being above both models and CEA predictions. It is shown that taking into account shock deceleration in the tube explains most of the discrepancy between measured and frozen radiance. For velocities above [Formula: see text], the data lies between the two models. However, adjusting for shock deceleration indicates that one of the models may be preferred for predicting [Formula: see text] dissociation. Finally, comparisons between OES and TDLAS data are made and show a good agreement on the measured temperature and [Formula: see text] number density profiles, typically within 10 and 5%, respectively. A good agreement is also observed for the radiance that would be inferred based upon the quantities measured by TDLAS.