Orville started out a shade too tongue-in-cheek (and a bit of touchy-feelie preachy), but settled down into some gritty SF.
Originally on plain old Fox, now all new episodes are on Hulu, who is producing, for now.
Expanse has been gritty SF almost from get-go. They have some science flubs in there (refer to Scott manel for details on that; and, he is a fan) but, it's good. SyFy hit this one out of the park in many ways. It has huge story arcs with a nuber of smaller one intersecting. It's had trouble "capturing" ratings as something close to 50% of SyFy's audience uses DVR, which don't get "booked." The series are short, intense, and filled with characters who are only fleshed out over the span of the episodes. SyFy had picked it up again, but it's not hit my DVR yet.
I have heard it's on Netflix, might be on other streaming services.
Expanse is almost too instense to binge-watch. Really, after a couple hours, you need a break just to collect your thoughts.
SyFy had another which started out good and gritty, but floundered after a while: Killjoys. Which were glactic bounty hunters operating in a troubled galaxy which was under a number of internal and external threats. The characters were engaging and fleshed out well, if in platoon quantity. That franchise has finally folded. Binge watchable.
HBO's Avenue 5 has been pretty good, even if it's hard to tell if it's satire or not (it's definitely satirical in nature, but that does not apper to be its purpose).
Westworld really pushed the boundries, and is decidedly worth a watch (depite unlikely to generate any spaceship models).