The Great Moving Van in the Sky
What do you associate with the names Leonardo, Donatello and Raffaello? Some people think of the great Italian masters and a few think of cartoon characters, but NASA engineers think of moving vans. These are the names given to the three Multi Purpose Logistics Modules (MPLM) flown on the Space Shuttle for temporary duty on the International Space Station (ISS).
Image to left: Leonardo is one of three MPLMs built by the Italian Space Agency that serve as pressurized, reusable cargo carriers between the ground and the ISS. Credit: NASA
The MPLM versions of Leonardo, Raffaello and Donatello are pressurized modules, or freestanding units, that are temporarily used on the ISS. MPLMs are cylinder-shaped and about 6.4 meters (21 feet) long and 4.5 meters (15 feet) in diameter, weighing almost 4 long tons (4.5 short tons), and capable of carrying up to 8.9 long tons (10 tons) of cargo. Each MPLM is sent to the ISS via the Space Shuttle, where the Shuttle's robotic arm lifts and transfers the module from the cargo bay to the ISS. It's then bolted in place, and power, data and water cables make it a fully functioning extra work area. Inside, there are racks of equipment and stowage items that the crew uses for daily living and specific experiments and procedures. When the materials have been used, the MPLM is then loaded with old equipment, racks and other items no longer needed. The robotic arm returns the MPLM to the Shuttle's cargo bay and it makes the return trip home. The MPLM is sometimes called a moving van, because its primary function is to carry loads of supplies from one location (Earth) to another (the ISS) and back again. Just like moving vans, they can be loaded with new cargo and sent out again and again.
Image to right: A Multi Purpose Logistics Module sits in the Space Shuttle cargo bay, waiting to be deployed. Credit: NASA
The modules are built to carry 16 ISS equipment racks. ISS racks aren't merely shelves, however. Racks on the ISS and Space Shuttle are self-contained cabinets that hold entire experiments or other projects. Each rack is a refrigerator-sized carbon fiber box, and from there, it can be customized to fit its need. Depending on the purpose of any given rack, the MPLM can be equipped with power, data and fluid to support refrigerators or freezers, or it can be used to stow excess materials. All modules include components that provide life support (oxygen, water and temperature control), fire detection and suppression, electrical distribution and computer capabilities.
The MPLM names reflect the involvement of the Italian Space Agency in providing the units to the ISS program. The three units were named to honor these men, who have been admired and respected for their contributions to our culture.
Image to left: The ground crew services an MPLM for launch. Credit: NASA
Why did Italy provide MPLMs for use on the ISS? It's one more example of the international cooperation that makes the International Space Station a success. The MPLMs were Italy's contribution, and in exchange, the Italian Space Agency was given access to research time on the ISS. The Italian Space Agency and their contractor Alenia began work on the MPLMs in 1995 and delivered the last of three modules in January 2001.
The names given to the MPLMs invoke the images of great Italian cultural icons, who probably never dreamed of working in an orbiting work station. Da Vinci, especially, would have loved to fly above the Earth. Some of his most notable inventions and designs focused on the mechanics of flight.