Great idea for a thread, Booman!
Those guys are officially called spacetroopers and have had action figures in recent years. I’ve seen behind the scenes photos of them being filmed, (back in the states just like the Cantina inserts) and the backpacks and airhoses were pretty much cobbled together as they were never going to be seen in closeup. (My Google Fu is failing me tonight, but the pics are out there.) The hoses just tuck in under the helmet. One of them was played by Joe Johnston.