Absent the effect of gravity hair strands have a tendency to straighten and spread out. Usually astronauts with long hair tie it up, but there are some pictures showing what this looks like:
Makes me wonder whether that's depicted in the manga.
This is the early Soviet space program, so they’re never out of the SK-1 space suit when in orbit, and it has a head covering the binds hair down. They make a point of being very accurate to the science and technology of the program, down to training and flight procedure.
So, it’s from a science fantasy light novel “Irina: The Vampire Cosmonaut” (Tsuki to Raika to Nosuferatu). The image is one of the posters. It was adapted in to a 2 volume manga and one season anime.