From the comments section, reposted here. Cant replicate the issue.

SkiRich [author] Just now
I'll look at it through your save game. I havent heard anyone else have this issue and I dont have this issue. It may be some incompatibility with another mod. I'm moving all this to a more permanent discussion in the mod called Bug Reports so we can post images and stuff.
BLÀde 9 minutes ago Delete
i disabled extended orbit and it's working again so it was that mod sorry i can't use it.
SkiRich [author] 2 hours ago
I tried your save. I'll post my result in your forum post you made.
Not an issue with this mod but some other mods.
BLÀde 8 hours ago
ok here it ia https://www.dropbox.com/s/1o4q1z5gt3px8p4/blade.savegame.sav?dl=0
SkiRich [author] 9 hours ago
You can copy your savefile to a dropbox link or someplace else and I'll retrieve it.
You can also try to disable all your mods and try the game with just Extended Orbit on.
BLÀde 10 hours ago
how do i send you a save. i'm using other mods though
SkiRich [author] 15 hours ago
Just did a long term test. Had the Extended orbit at 475 when rocket arrived.
Waited till its said 10 hrs left to land. Colonists were fine. @Blade, you have something else going on.
SkiRich [author] 18 hours ago
@Blade, this mod doesnt change any of mechanics of why or how colonists survive. It only adjust the time in orbit. Thats it. If your colonists die then there is something else you got going on. If you want, you can send me a save game and I can take a peek.
BLÀde 22 hours ago
i'm at sol 55 and colonists die every time now i try land i suspect this mod is the cause?