If you would like to see more articles like this please support our coverage of the space program by becoming a Spaceflight Now Member. If everyone who enjoys our website helps fund it, we can expand and improve our coverage further. The Space Launch System’s four RS-25 engines fire during an abbreviated Green Run test Saturday. Credit: NASA A critical test-firing of NASA’s Space Launch System moon rocket in Mississippi ended just 67 seconds after it began Saturday, well short of a planned eight-minute burn that was supposed to clear the way for the space agency to finally ship the rocket’s core stage to the Kennedy Space Center in Florida for launch preparations.