Carrier-based aircraft must be sturdy enough to withstand demanding carrier operations. They must be able to launch in a short distance and be sturdy and flexible enough to come to a sudden stop on a pitching flight deck; they typically have robust folding mechanisms that allow higher numbers of them to be stored in below-decks hangars and small spaces on flight decks. These aircraft are designed for many purposes, including air-to-air combat, surface attack, submarine attack, search and rescue, matériel transport, weather observation, reconnaissance and wide area command and control duties.