International Space Station (ISS)

STS-102 mission astronaut Susan J. Helms translates along the longerons of the Space Shuttle Discovery during the first of two space walks. During this walk, the Pressurized Mating Adapter 3 was prepared for repositioning from the Unity Module's Earth-facing berth to its port-side berth to make room for the Leonardo multipurpose Logistics Module (MPLM), supplied by the Italian Space Agency. The Leonardo MPLM is the first of three such pressurized modules that will serve as the International Space Station's (ISS') moving vans, carrying laboratory racks filled with equipment, experiments, and supplies to and from the Station aboard the Space Shuttle. The cylindrical module is approximately 21-feet long and 15- feet in diameter, weighing almost 4.5 tons. It can carry up to 10 tons of cargo in 16 standard Space Station equipment racks. Of the 16 racks the module can carry, 5 can be furnished with power, data, and fluid to support refrigerators or freezers. In order to function as an attached station module as well as a cargo transport, the logistics module also includes components that provide life support, fire detection and suppression, electrical distribution, and computer functions. NASA's 103rd overall mission and the 8th Space Station Assembly Flight, STS-102 mission also served as a crew rotation flight. It delivered the Expedition Two crew to the Station and returned the Expedition One crew back to Earth.