Dead Space executive producer Glen Schofield described in detail the birth and development of the project in a
recent interview.Most of the interview describes the process by which the game was pitched, prototyped, and after one year, greenlit. Apparently, it was easy for Schofield to get the go-ahead from
EA to start prototyping, because the company had already committed itself to creating new IPs. It took first 18 and later 25 people to create three prototypes (to test gameplay concepts and the game's in-house engine, called the Saber Engine) over the course of one year before the project received the greenlight to begin full development.
Schofield also let slip at the end of the interview that his team is aiming to pack about 20 hours of gameplay into
Dead Space. That's close to par for the course for
Survival Horror.