This work focuses on the study of plasma effects having an influence on the aerodynamic properties of a rarefied Mach 2 air flow interacting with a cylinder. The effect of a DC glow discharge plasma on the shock wave resulting from the interaction of a Mach 2 supersonic rarefied flow and a cylinder is being studied experimentally and numerically. The flow field is experimentally analysed with a iCCD camera and the experimental images are compared to the calculated Mach number fields. Rotational temperatures deduced from emission spectrometry help to improve physical interpretation by refining input data in the simulation code. The experimental investigation was carried out in the supersonic wind tunnel Marhy located at the Icare laboratory and a numerical investigation using a fully 2D compressible Navier Stokes simulation was carried out at the IUSTI laboratory.