LoTEC© is a passive thermal carrier designed to maintain the temperature of biological samples for ten days or more for transport to and from the International Space Station (ISS) without the need of external power. LoTEC© relies on a combination of high thermal resistance insulation and high energy density storage phase change materials. The initial capability of LoTEC© encompasses several temperature ranges (e.g. 36 to 40C, 18 to 22C, 0 to 4C, and - 16 to -20C). LoTEC© fits into a standard mid-deck locker or an Express Rack locker; this facilitates easy transfer between the shuttle and the ISS. Thermal analysis modeling and laboratory test results are presented that characterize the performance of LoTEC© and the planned PCM materials.