NASA - National Aeronautics and Space Administration

The Permanent Multipurpose Module of the International Space Station is featured in this image photographed by an Expedition 26 crew member. Credit: NASA

Expedition 30 Commander Dan Burbank is pictured among stowage containers in the Leonardo Permanent Multipurpose Module. Credit: NASA

Derived from the Leonardo Multipurpose Logistics Module (MPLM), the Italian-built Permanent Multipurpose Module (PMM) is attached to the Earth-facing side of the Unity node. The PMM is a large, reusable pressurized element that was originally used to ferry cargo back and forth to the station. It added 2,472 additional cubic feet of pressurized volume for storage and for scientific use, and it can hold up to 16 racks of equipment, experiments and supplies. It also has an end-cone that has additional storage space for cargo bags and other items.

To transform an existing logistics carrier used for 10 years into a permanent module able to stay an additional 10 years in orbit, modifications consisted of the following:

• Enhancing the module shielding with an improved micrometeoroid debris protective shield design to satisfy the new penetration requirements
• Providing an in-orbit maintenance capability by changing the internal harness routing and brackets layout to allow crew access to internal equipment
• Providing easy interfaces
• Providing a certified life extension for all equipment and subsystems
• Developing a software update to eliminate faulty alarms

The Italian Space Agency contracted with Thales Alenia Space, which also designed and built the three multi-purpose logistic modules, to make the modifications. This module flew seven times as Leonardo, the multipurpose logistics module.

PMM Specifications
Length	22 feet
Diameter	14 feet
Payload mass at launch	28,353 pounds
Empty weight	21,817 pounds
Launch date	2/24/11