On the rocky seashore of Santa Catalina Island, California, astronauts Drew Feustel, Norishige Kanai, and Thomas Pesquet are conducting a week of undersea analog training. NEEMO NXT is training them for lunar excursions, with a submersible “rover” and “spacewalks” in simulated lunar gravity using a partially-buoyant diving suit. Uniquely for the NEEMO program, this effort does not involve overnight stays in an aquatic laboratory – the trainees get to breathe fresh air each night. The NXT mission is hosted by the University of Southern California Wrigley Institute for Environmental Studies.
Meanwhile, Nick Hague and Andrew Morgan set out for ISS EVA218 on 21 Aug 2019 at 1148 UT to install a PMA-to-IDA docking adapter. A twenty-year-old space station will develop logistics problems over time. Oddly enough, one of those problems is what shape the doors should be.
Today, there are three different types of docking ports on the ISS. Not long ago, there were four. The work today finally eliminated the old Pressurized Mating Adapter (PMA), which dates back to Shuttle-Mir. An adapter unit converted the last open PMA port to the International Docking Adapter (IDA) hatch design.
In addition to the newer IDA, the older-style Common Berthing Mechanism (CBM) is still available. Russian Progress and Soyuz spacecraft will continue to use the separate SSVP docking system.