Thinking about how sign language would work for people who live and work in space, like in Planetes or the Belters in The Expanse. Modern sign language like ASL relies on a lot of emoting and body language, but obviously you don't have that in a space suit, which is a big reason for everyone to know a sign language. So you'd probably wind up with a halfway point between that, and the hand signals that cops and soldiers use.
@Zero_Democracy a total utilitarian sign language rework sounds quite appealing. is there any mathematically based conclusion we could draw on ideal grammatical structure, for instance? there are many constructed languages, but if there were one that were practical enough maybe it could catch on under that basis alone.
I love your metion of the belters. They absolutely WOULD adapt a gestural language like that.