Lego frequently comes out with various themed sets with science fiction or fantasy themes, often with a back story. An example would be the [Mars Mission sets](http://lego.wikia.com/wiki/Mars_Mission). 

As per the Brickipedia page:

> 
> The theme focuses on the adventures of a team of Astronauts as they
>  land on Mars and are forced to contend with a dangerous alien race.
> 
> 
> 

I was wondering whether these would be considered to be on-topic for this site. Note I'm specifically asking about the **story** behind these series of Lego sets, *not* about the Lego sets themselves.