What makes a good sci-fi story?

[A very special guest]

In my experience, I found that a good sci-fi story frequently has a mix of the following:

1) A philosophical issue to explore with a "what if" scenario.
2) A moral lesson that is sometimes connected to the philosophical issue.
3) A parallel reality that mirrors current political climates so readers can relate to the story.

I found the Star Trek series was very good at this.

What are your thoughts on this?
What other attributes have you notice in other good stories?

A grounding in good science, with a futuristic bent.
As opposed to Science-Fantasy which does not need to have the above.

 

[JohnnyDoe]

I prefer it when the story is based more on the plot than the scientific explanation...

 

[JohnnyDoe]

I prefer it when the story is based more on the plot than the scientific explanation...