Aerodynamics of re-entry bodies is one of the most critical aspects of design for any space missions. The velocity of a re-entry body varies from hypersonic Mach number in outerinner atmosphere to supersonic, transonic and finally subsonic Mach numbers till it touches down on earth. Generally, a bluff body is chosen for re-entry missions. Flow over multiple bluff bodies (two or more) in proximity is a very interesting topic and it has wide variety of applications in the area of aerospace engineering. An attempt has been made to study the aerodynamics of pair of separating bodies in tandem at subsonic Mach number. This separation event occurs when apex cover is separated from re-entry module before the deployment of drogue chutes. In this study reentry module is considered as fore body and apex cover as aft-body. CFD studies have been carried out to estimate drag coefficient of the aft-body using two different CFD software FLUENT and CFD++. The effect of gap on axial force coefficient of aft body placed at various axial distances from the fore body, at subsonic Mach number and zero degree angle of attack, is the subject of this paper.