Single Status Update
Ohhhh, you like Planetes! It’s one of my favourite (maybe even my number one). Recommend any similar hard sci-fi shows??
That's really difficult. "Hard" SF is pretty uncommon. Softer stuff is so much easier to make, and usually pays as much or more than SF that tries to do the science well. Most of the audience can't tell the difference anyway, so why bother?
That said, my favorite is probably Ghost in the Shell. Another cyber-themed one was Dennou Coil. It played the tech kind of loose, but it never quite veered into "fantasy" territory. I'd consider the first "Aincrad" arc of Sword Art Online as "hard" as well, though the science part was mostly just a plot device to bridge into the fantasy story.
If you're looking for space-themed stuff there's Space Brothers, though that's more a slice-of-life type that just happens to feature contemporary NASA astronauts instead of school kids. If you can find it I thought Moonlight Mile was decently "hard", as was Rocket Girls.
MM is probably closest in theme and style to Planetes. It is a bit more "adult" and serious than Planetes, but if you liked Planetes then it might be worth a look.
That's all I can come up with at the moment. Like I said, there's not much out there.