Looking to the future, NASA is investigating several technologies that will allow it to accomplish some bold objectives. This includes returning to the moon, creating the infrastructure that will let us stay there, sending the first crewed mission to Mars, exploring the outer solar system, and more. This is particularly true of propulsion technologies beyond conventional chemical rockets and engines. One promising technology is the rotating detonation engine (RDE), which relies on one or more detonations that continuously travel around an annular channel.