NASA says preparations are underway to relocate one of the storage modules on the International Space Station (ISS), in the biggest change to the orbiting laboratory's configuration since assembly was completed in 2011.
The ISS is being reconfigured to facilitate future arrivals of U.S. commercial cargo and vehicles, the space agency said in a release.
On May 27, the large Permanent Multipurpose Module (PMM), utilized as a supply, will be moved from the Earth-facing port of the station's Unity node and robotically relocated to the forward port of the Tranquility node.
The move will be made using the station's 58-foot Canadian-built robotic grapple arm, and is scheduled to take a few hours.
According to the NASA statement, this will "create primary and back up docking ports for U.S. commercial crew spacecraft currently in development by Boeing and SpaceX to once again transport astronauts from U.S. soil to the space station and back beginning in 2017."
The move will make the Unity port available for conversion into a spare berthing location for U.S. cargo spacecraft — as a backup for the primary docking port, located on station's Harmony module.
Currently the spare berthing location for cargo vehicles, the Harmony port will become the arrival location for commercial crew-carrying spacecraft.
The module move will be broadcast on NASA Television beginning at 8 a.m. EDT on May 27.
ISS Expedition 43 Commander Terry Virts, along with Flight Engineer Scott Kelly, will oversee the separation of the PMM from the Unity node and its attachment to the Tranquility node.
The hatch between the PMM and Tranquility will be opened on May 28.
International Docking Adapters for the newly configured crew arrival ports will be brought to the ISS on future SpaceX cargo resupply missions, NASA said.
Originally dubbed "Leonardo" by the Italian Space Agency in charge of its manufacture, the PMM weighs almost 11 tons. It is 22 feet long and 14 feet in diameter, with an an internal volume of more than 2,400 cubic feet.
It was one of three cargo identical modules built to carry supplies from Earth to the ISS during space shuttle assembly missions.
The PMM was left at the ISS permanently after a journey to the space station aboard the shuttle Discovery, in its last mission before retirement.
