The landing gear was a component of some spacecraft which were capable of entering a planet's atmosphere and landing on the surface. Before the introduction of spacecraft, landing gear was used for aircraft.
One notable class of starship which possessed landing gear was the Intrepid-class, such as the USS Voyager. Voyager used its landing gear, which were called landing struts, on several occasions during its journey through the Delta Quadrant. (VOY: "The 37's", "Dragon's Teeth")