The Martian was supposed to be directed by the one and only Drew Goddard, as he was the writer behind the book of the same name the movie would be based on. However, the film did not move forward after he had adapted the book into screenplay, and therefore he became replaced by Ridley Scott. The movie then started moving forward, the actors for the main characters were chosen, and the filming began.
Obviously, the movie was strongly influenced by Drew Goddard and his book. It followed the same storyline, with the same characters and characteristics as the original book. It was even based on the screenplay Goddard wrote when he was planned to be the director of the movie.
Scott also put in his own sparks into the book and made it more "his own". He wanted the "no one gets left behind" moral to be clear throughout the story of survival, instead of having too much focus on the technical sides of the storyline.
