Abstract: There is provided a heat pipe assembly 10 formed of dissimilar materials for the heat pipe 18 integrated with the host structure 16 in a manner that optimizes removal of unwanted heat generated by various devices on a space or terrestrial platform 14. A conventional heat pipe construction 18 mounted within a circular cross-section channel 28 formed in a retaining block 26 leaving an annular gap 30 between the outside surface wall 33 of the heat pipe and the inside surface wall 32 of the channel 28. A heat conductive fluid 40 is injected into the annular gap 30 permitting the dissimilar CTE materials to thermally expand and contract as the platform or structure 14 experiences extreme temperature changes.