You can watch the historical record of the WW2.
The beginning of the story "Gravity Rainbow" authored by Thomass Pynchon, is the scene in which the soldier happend to see the vapor trail of the Rocket attacking London.
The author expands its authentic imagination to enrich his story by exploiting the achievement of the various natural and social science .
Readers who do not have any experiences on WW2 can virtually enter into the era of the Great War at the stage of London.
Any fictious story can not be separated fron the reality,even if the author try to separate his story from all the reality.So what the professional reader"scholor" can do is to extract the essence of the history which made the author create the splendid novel.
By doing this you can follow the meaning of the story along with the will of the author and its texts.
The V2Rocket ,which you can see in the video on the Youtube, is what I call the essence of the story .
MIT AeroAstro: Department of Aeronautics and Astronautics
You can see the process of development of the rocket by scientists and Army of Nazi Germany by this film