SpaceX is fresh off a high for its Starship spacecraft development program, but according to CEO Elon Musk, it’s already looking ahead to potentially repeating its latest success with an unplanned early reusability experiment. Earlier this week, SpaceX flew the SN15 (i.e., 15th prototype) of its Starship from its development site near Brownsville, Texas, and succeeded in landing it upright for the first time.