NASA's Mars-bound mega rocket ahead of schedule, on budget
The towering Space Launch System
(SLS) is a 384-foot (117 meters) behemoth intended to launch astronauts beyond low-Earth orbit to deep-space asteroids and Mars. The vehicle is slated to make its first test flight in 2017, when it will launch an unmanned Orion capsule
(also in development) beyond the moon. The first manned flight is pegged for 2021.
So far, NASA and The Boeing Co., which has been contracted to build the rocket's core stage, are on track to meet that date, officials said.