Aeronautics (from the ancient Greek words ὰήρ āēr, which means "air", and ναυτική nautikē which means "navigation", i.e. "navigation of the air") is the science or art involved with the study, design, and manufacturing of air flight capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identifies the aspects of "aeronautical Art, Science and Engineering" and "the profession of Aeronautics (which expression includes Astronautics)."