ISS robotic operations, spacewalk, further prepares laboratory for commercial vehicles. Building on the work completed by spacewalking astronauts March 26, ISS mission controllers robotically relocated Pressurised Mating Adapter 3 to prepare for the arrival of commercial crew spacecraft March 26.
Using the station’s Canadarm 2, PMA-3 was detached from the Tranquillity module - where it has been located since 2010 - and moved to upper berthing port of the Harmony module. A second spacewalk made by Expedition 50 Commander Shane Kimbrough and Flight Engineer Peggy Whitson April 30 connected the adapter’s umbilical cables to the Harmony module completing PMA-3′s installation. Known as EVA-41 in the US’s EVA manifest, it was the 199th spacewalk conducted for ISS assembly and maintenance. While the astronauts were installing micrometeroid shields to the now-vacant berthing port on Tranquillity, one of the four shields floated away forcing the spacewalking astronauts to use a now-unneeded thermal shield from the PMA.
During this time Whitson became the most experienced female spacewalker, ultimately logging more than 53 hours and 22 minutes outside a spacecraft when the EVA officially ended.
Diagram showing the location of PMA-3 before and after its relocation March 26.
Since 2015 the International Space Station has been undergoing reconfiguring to allow for the impending arrival of two U.S. commercial crew vehicles. May of 2015 saw the relocation of the Permanent Multipurpose Module from the Unity module to Tranquility, freeing up an additional berthing space for commercial cargo vehicles. A second International Docking Adapter is set to arrive at the orbiting laboratory in 2018 and will be attached to PMA-3. The first docking adapter, IDA-2, is currently attached to PMA-2 also on the Harmony module. The International Docking Adapter acts as an interface between the older APAS-95 docking system installed on the PMA’s and the newer NASA Docking System that future commercial crew vehicles will be outfitted with. Reconfiguring the US Orbital Segment is the largest external modifications made to the International Space Station since its assembly was completed in 2011. Below, the configuration of the station’s Harmony module in 2018, showing both Pressurized Mating Adapters and International Docking Adapters. PMA-3 was relocated to the module March 26. IDA-3 is scheduled to arrive at the complex in 2018.
P/C: NASA