Under NASA 's New Millennium Program Space Technology 8 Project , four experiments are being developed for future small system applications requiring low mass , low power , and compactness . GSFC is responsible for developing the Thermal Loop experiment , which is an advanced thermal control system consisting of a miniature loop heat pipe ( MLHP ) with multiple evaporators and condensers . The objective is to validate the operation of an MLHP , including reliable start - ups , steady operation , heat load sharing , and tight temperature control over the range of 273 K to 308K. An MLHP Breadboard has been built and tested for 1200 hours under the laboratory environment and 500 hours in a thermal vacuum chamber . Results of the TV tests are presented here .