A thermal management system using heat pipe principles and incorporating capillary-pumped equipment mounting panels such that a heat transport loop without moving parts is provided. The panels can function to either absorb heat or to reject heat and can interface with heat generating equipment or heat radiators. Each panel comprises a pair of coextensive flat plates bonded together with a thin, fine-pore sheet wick interposed therebetween. A network of liquid grooves in one plate is in fluid communication with the sheet wick which covers the grooves and most of the plate and a separate liquid line connecting the panels. A network of vapor channels in the other plate is in fluid communication with the wick and with a separate vapor line connecting the panels. The vapor channel networks of the panels and the liquid groove networks of the panels are connected such that the panels are arranged in parallel in the fluid circuit or loop. A heat input into panels in the loop causes evaporation of liquid off the surface of the sheet wick. Vapor from the evaporated liquid is circulated to panels serving as cold sinks where the vapor is condensed. Capillary action of the wicks returns the condensate to the panels being heated where the cycle is repeated.