Devin Faraci from Chud managed to corner the legendary director and got this answer out of him when asking if the prequel will span more than just the one movie.
"It’ll be prequel one and two. Then Alien 1." - said Ridley Scott.
He was also asked if he would possibly film both movies at the same time but that doesn't seem likely,
"'At the moment I’m just trying to get the first one out,'" said Scott.
So what do you think? Is Scott developing his own trilogy of Alien movies here that ends with the first one? Or are two prequels a pipe dream? I think it sounds cool personally - with two movies there's room for way more stuff that won't be rushed into the first Alien film.