I don't think that this is the right board for this. I think you just want the "Share Your Sims Stories and Projects" main board, which does have a lot of tips for writers. This is just for the stories themselves. Maybe ask one of the mods to move it over for you?
For Feedback though, I'm going to say to make sure that you have enough strong conflict to carry the story. Like in your first story, I know that it's just a broad summary, but to me, it looks like that things are going great until the husband dies at the end. I could very well be wrong though, and you do have a lot of conflict planned, like maybe the female protagonist resents her husband because she had to move away from her friends and family and he's too busy training and spends less time with her than she needs, or maybe she's staying with her family (parents, siblings, cousins, etc) while her husband's working to become an astronaut, and maybe her family's worried that he's failing at being a good husband and that she should divorce him, and she's starting to wonder if they're right. Point is, you need an ongoing problem that's only resolved at the end of the story. And provide forshadowing that the shuttle is going to explode, or at least that something horribly bad is going to happen, otherwise it can just come off as emotional manipulation.
And another tip is to make them sound and act like real characters, since your story ideas are very character driven. Try to steer clear of having characters do things just for the sake of being evil, mean, good, etc. Give them goals that they want to achieve, motives that they have, memories, likes, dislikes, etc. Give them layers. Even any villains you have. For example, don't just have the guy's wife in the second story take off for a change of scenery because she's a horrible, awful person and leave it at that. Give her a valid reason for wanting to leave. She can still be a cold, horrible person, but she'll be more rounded and realistic.