[quote=@Cerces22]
[@Balthazar007]

Now are time sensitive missions story driven missions??
[/quote]

All missions are either driven by the story or help drive the story (i.e. they are pulled by the story or push the story along). It's really the mission rank that is important here. "A" rank missions do some heavy pushing/advancing of the plot. While "D" rank missions are consequences of what has already happened in the story. 

Does this answer your question?