The best space exploration game I've played is Outer Wilds (https://store.steampowered.com/app/753640/Outer_Wilds/), but instead of the NMS sandbox there are puzzles.
In that configuration, the mechanic is still there but you aren't feeling on a clock anymore and can explore and play around with stuff at your own pace.
As someone hating any kind of timed missions in games, that's what made a frustrating game into a masterpiece for me personally.
For example there might be a wormhole that takes you to a different destination if you fly through it backwards. You're very unlikely to find that out by chance, but if you explore you'll find a thing that tells you (probably behind some other puzzle).
Great game.
I'm not saying ending was perfect, but I can't think of a better way of ending it.