The SLS core stage booster arrives at Kennedy Space Center. Photo: Boeing The final piece of NASA’s next moon rocket was unloaded Thursday at Kennedy Space Center ahead of an uncrewed launch to the moon and back later this year. The core stage of NASA’s Space Launch System, or SLS, rocket arrived by barge earlier this week after undergoing testing in Mississippi. The 212-foot tall, 188,000 pound booster will help lift NASA’s Orion space capsule, designed to take future human missions to the moon. The two solid rocket boosters that help lift the massive rocket have already been assembled and the capsule is undergoing its final checkouts before mating with the rocket.