One thing, and I haven’t figured this out, because I haven’t spent any time on it: if you look at photographs of machines in space (satellites, orbiters, etc) they have very VERY harsh shadows. Pretty sure this is due to the lack of ambient light in space. Now, planets with atmospheres, not so much. The moon, of course, has harsh shadows. But if you look at the earth, it always has fuzzy, soft shadows going to the dark side. The other part is that when something is in shadow, it merges with the background black of space, becoming invisible.
So if you want to make your renders look hyper real, you’ll figure this part out… and when you do, you WILL tell me how you did it!