"Destiny" arrived at the station pre-configured with five racks housing electrical and life support systems that provide electrical power, cooling water, air revitalization, and temperature and humidity control. Seven additional racks were flown to "Destiny" in the "Leonardo" Multi-Purpose Logistics Module by STS-102, and ten more were delivered on subsequent missions. "Destiny" can hold up to 13 payload racks with experiments in human life science, materials research, Earth observations and commercial applications. The laboratory has a total of 24 racks inside the laboratory, six on each side.