Because of their shape, circular aircraft can theoretically move anywhere—up, down, and side to side—without needing to point in that direction. This provides the potential for highly attractive vertical-takeoff-and-landing (VTOL) or short-takeoff-and-landing (STOL) capabilities, the latter of which permits the use of a far shorter runway than is needed by conventional craft of the same size. Armed forces worldwide are especially interested in VTOL and STOL airplanes because they can lift off from cramped aircraft-carrier decks or almost any flat surface in remote locations where runways are not available. Round aircraft are also advantageous in principle because they could fly faster than the other notable VTOL aircraft, helicopters, and their thin shapes are potentially far less detectable by radar, making them ideal for covert reconnaissance missions. Not to mention, the concept is just plain cool.