For any electronic equipment to function properly heat generated in it must be dissipated so that temperature does not rise above the threshold operating limit. In outer space applications, usually the electronic equipment is mounted on to the satellite structure using bolted joints. Thermal contact conductance (TCC) between the base plate of the electronic component and the satellite structure/heat sink plays a critical role in determining the heat transfer rate between them and hence the equilibrium temperature attained by the electronic component. In this work, TCC is compared for an interface formed by an electronic package base plate mounted using a single bolt on to the structure/heat sink plate both made of AA 6061 (an aluminium alloy). The TCC for this configuration under three conditions is compared viz. (a) in vacuum (b) in atmospheric conditions and (c) with thermal interface material (TIM). The vacuum condition represents the actual outer space conditions where there is no convection. Experiments are performed for a fixed bolt torque for all the three conditions. Steady state temperature measurements are obtained at predetermined sensor locations on the top plate using the heat transfer experiments. Higher temperature on the top plate means lower TCC at the interface.