(AW) The Dynetics concept of a Saturn F-1 engine is upgraded for Space Launch Systems (SLS) via modern manufacturing. Space Launch System eyed as the platform for a new U.S. hydrocarbon rocket engine Before the dust settles from the post-shuttle shift in human access to space, the U.S. could find itself with a big new high-performance hydrocarbon rocket engine to boost NASA’s planned heavy-lift Space Launch System (SLS) off the pad. There is a chance it might even replace the Russian-built RD-180 that carries the United Launch Alliance Atlas V.