Nasa ISS

Nasa is preparing to reconfigure the International Space Station (ISS) to create primary and back-up docking ports for the US commercial crew spacecraft.

Docking ports will also be re-organised for future commercial spacecraft that will deliver research, supplies and cargo for the crew.

Boeing and SpaceX are working on the spacecraft to transport astronauts from the US to the orbiting laboratory, with plans for a return journey in early 2017.

On 27 May, the large Permanent Multipurpose Module (PMM) on the ISS will be robotically moved to the forward port of the Tranquility module from the current Earth-facing port of the Unity module.

Nasa plans to convert the Unity port into a spare berthing location for the cargo spacecraft, while the Earth-facing port on Harmony will be the primary docking location. Harmony’s space-facing port is currently the spare berthing location for cargo vehicles.

Expedition 43 Commander Terry Virts and flight engineer Scott Kelly from Nasa will oversee the PMM attachment to Tranquility.

"Harmony’s space-facing and forward ports will be prepared for crew arrivals later this year."

The module’s hatch will be closed on 26 May and re-opened at its new location.

Nasa said that Harmony’s space-facing and forward ports will be prepared for crew arrivals later this year.

The agency will deliver a pair of international docking adapters (IDAs) onboard the seventh and ninth SpaceX cargo resupply missions, to attach them to pressurised mating adapters two and three, which will allow the spacecraft to balance internal pressure with the ISS.

Originally named Leonardo, the 22ft-long PMM has an internal volume of more than 2,400ft³ and is designed to drag supplies back and forth from the station during space shuttle assembly missions.

Image: Illustration of the PMM’s current (blue) and new (green) locations on the ISS. Photo: courtesy of Nasa.