NASA continues to push forward with the design of its new heavy lift rocket, the Space Launch System. With the cancellation of the Constellation Program, SLS is NASA’s planned heavy launch vehicle at the moment. While commercial entities continue to tackle the problem of moving payloads and crews to low Earth orbit, SLS is intended to replace the Space Shuttle as a heavy lift platform for shifting large cargoes into low Earth orbit and points beyond.
If SLS is ever to actually fly, it will require a tremendously powerful set of engines to get it off the ground. Perennial launch contract winner ATK is sure to get in on the action, supplying solid rocket boosters to the launch stack. But a powerful liquid-fueled engine is required as well. There are many candidates and design options, but NASA is actually turning its gaze a bit toward the past for inspiration.