The Raffaello Multi‑Purpose Logistics Module (MPLM) arrived at Kennedy Space Center in August 1999 after construction in Italy. This helped prepare a new way to move large amounts of pressurized cargo to and from the International Space Station (ISS) using the Space Shuttle.
Space Shuttle Discovery launched STS-102 carrying Leonardo, the first MPLM used with the ISS. The mission demonstrated the “moving van” concept: a pressurized module temporarily attached to the station so crews could transfer racks, supplies, and experiments in a shirtsleeve environment.
STS-100 launched with the Raffaello MPLM and transferred thousands of pounds of cargo to the ISS. In parallel, the mission installed Canadarm2, the station’s main robotic arm, which became essential for later assembly tasks and for moving modules like the MPLMs into position.
STS-105 launched with Leonardo on its second ISS flight, highlighting how the MPLM system could be reused. The crews used the module to move large amounts of equipment and supplies into the ISS and to load return cargo back into Leonardo for landing on Earth.
STS-111 brought Leonardo to the ISS again and then packed it with equipment and supplies for return to Earth. This reinforced the MPLM role as a two‑way logistics carrier, not just a delivery container, supporting station upkeep as assembly continued.
After the Space Shuttle fleet returned to flight, STS-114 flew Raffaello to resupply the ISS. The mission showed that the MPLM approach still fit the post‑Columbia safety era while meeting the station’s growing need for spare parts, food, and other essentials.
STS-121 launched to the ISS during a period when shuttle flights focused heavily on maintaining and supplying the station while also improving shuttle safety. This context matters because MPLM flights were part of a broader strategy to keep ISS operations stable while construction advanced.
STS-122 delivered and helped install the European Columbus laboratory, marking a major step toward a more fully equipped research station. As the ISS gained lab capacity, logistics modules like the MPLMs became even more important for delivering experiment hardware and support equipment.
STS-126 carried Leonardo and mated it to the Earth‑facing (nadir) port of the Harmony node, showing that MPLM berthing could be done at different ISS locations as the station’s layout evolved. This flexibility helped planners manage crowded docking and berthing ports during peak assembly years.
STS-128 launched with Leonardo carrying life support and science racks, reflecting the ISS’s push toward more capable long‑duration operations. Moving these large racks through a pressurized MPLM reduced the time and complexity of loading cargo through smaller hatches and pathways.
STS-131 brought Leonardo again as a major cargo carrier, supporting the ISS while external hardware and systems were still being installed and upgraded. During the mission, unberthing the MPLM required careful work with the Common Berthing Mechanism (CBM), the station’s mechanical-and-sealing system for connecting pressurized modules.
On STS-133, Discovery carried a modified Leonardo intended to stay on orbit as the Permanent Multipurpose Module (PMM). This decision changed Leonardo’s role from a reusable shuttle cargo carrier into a permanent part of the ISS, adding long‑term pressurized storage volume.
The PMM was installed on the ISS on March 1, 2011, becoming a permanent pressurized element rather than a temporary visiting module. This marked a clear endpoint for the MPLM era tied to routine shuttle logistics and a transition to post‑shuttle station operations with on‑orbit storage built into the station itself.
Leonardo Permanent Multipurpose Module and MPLMs: Shuttle Deliveries and ISS Integration (1999–2011)