A new type of high capacity heat pipe for spacecraft use has been fabricated and tested. The heat pipe consists of an outer pipe and an inner pipe. The outer pipe is a container and it has two channels, one for liquid and one for vapor. The inner pipe is provided with axial grooves and circumferential slits, and it is inserted into the vapor channel of the outer pipe. The circumferential slits connect the liquid channel and the axial grooves. Preliminary test results for the first 1 m long development model are presented and discussed relating to its heat transport capacity. 資料番号: SA0033543000