Astronaut Paul W. Richards, STS-102 mission specialist, works in the cargo bay of the Space Shuttle Discovery during the second of two scheduled space walks. Richards, along with astronaut Andy Thomas, spent 6.5 hours outside the International Space Station (ISS), continuing work to outfit the station and prepare for delivery of its robotic arm. STS-102 delivered the first Multipurpose Logistics Modules (MPLM) named Leonardo, which was filled with equipment and supplies to outfit the U.S. Destiny Laboratory Module. The Leonardo MPLM is the first of three such pressurized modules that will serve as the 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.