Demo
    A large cylindrical rocket section stands vertically in a spacious industrial assembly facility, with engineers examining nearby equipment.
    The liquid hydrogen tank is part of the core stage for the Space Launch System. The rocket’s first flight is set for late 2018, but NASA would need to accelerate its launch pace to sustain astronauts in cislunar space.
    A robotic rover with a gold thermal cover and a mechanical arm on a sandy, rock-strewn terrain under a partly cloudy sky.
    The Resource Prospector prototype searches for a buried sample tube at NASA’s Johnson Space Center in Texas in 2015. Intensive robotic exploration of the moon could locate water ice and supply propellant for an astronaut return.