"NASA is beginning a preliminary design review for its Space Launch System (SLS). This major program assessment will allow development of the agency's new heavy-lift rocket to move from concept to initial design.
The preliminary design review process includes meticulous, detailed analyses of the entire launch vehicle. Representatives from NASA, its contractor partners and experts from across the aerospace industry validate elements of the rocket to ensure they can be safely and successfully integrated.
... We are on track and meeting all the milestones necessary to fly in 2017."