Abstract: Equipment support and thermal radiation panels for a spacecraft include a transverse header heat pipe and a set of a plurality of "spreader" heat pipes each including an elongated longitudinal portion and an "L" portion lying in thermal contact with the header heat pipe. The elongated longitudinal portions of the spreader heat pipes are spaced apart and mutually parallel. A further set of spreader heat pipes, similar to the first set, is provided. At least part of the elongated longitudinal portion of each further heat pipe is physically parallel, and in thermal contact, with a heat pipe of the first set, and the "L" portions of the further heat pipes are in thermal contact with a second header heat pipe. A make-break thermal joint juxtaposes a header heat pipe of each of two panels lying in different planes.