The Space Launch System (SLS), the super-heavy lift launch vehicle designed to launch crewed missions beyond low Earth orbit (LEO), has passed a combination system definition review/system requirements review, allowing engineers to start finalizing the design.
The rocket, scheduled for first flight in 2017, has now been formally moved into the preliminary design phase. Given the extensive use of off-the-shelf components built for other spacecraft and previously-done design work, the preliminary design phase is not expected to take long, though NASA officials were unavailable to answer schedule questions.
The SLS will be the most powerful launch vehicle ever built, capable of lifting 130mt to LEO in its planned final form. The first flight, in 2017, will be an interim model using an upper stage adapted from the United Launch Alliance Delta IV, and solid rocket boosters from the Space Shuttle programme. The first flight of the complete version will be in 2021 or later.
The rocket is designed specifically to launch a crewed Lockheed Martin Orion capsule on missions outside LEO. While no missions beyond initial test flights have been confirmed, possible destinations include a return to the moon, or trips to Mars or a nearby asteroid.