nednobbins t1_jaelc5r wrote on February 28, 2023 at 9:42 PM

Reply to comment by ForgiLaGeord in China to expand its space station, international astronaut selection underway by ye_olde_astronaut

Yeah. I'm wondering how scalable that is.

I had initially assumed that the sort of infinite scalability you see in video games is just for video games and that in an actual space station you would run into some practical considerations that keep you from just adding modules indefinitely.

Now I'm starting to doubt that assumption.

SteveMcQwark t1_jaex0wr wrote on February 28, 2023 at 11:02 PM

On the one hand, you don't have gravitational loading for the most part (there's some because of various forces that get applied to a space station during operation, but not at the level you'd have on the ground). However, you can get structural oscillations which behave somewhat differently than they do on the ground, as well as various torques that get applied throughout operation. And because of weight considerations during launch, space structures are often made of aluminum, which doesn't have a fatigue limit, so it will weaken over time even for minor stresses. You hear about fractures being found in the walls of Russian ISS modules because of this. These effects get worse as you scale up a structure.

nednobbins t1_jaezmpx wrote on February 28, 2023 at 11:20 PM

That all makes sense and I did expect that there were some practical limits I hadn’t thought.

It sounds like there are but they may be higher than I had first guessed.