An aerostat (From Greek ἀήρ aer (air) + στατός statos (standing) through French) is a lighter than air craft (the average density of the craft is lower than the density of atmospheric air) that gains its lift through the use of a buoyant gas. Aerostats include unpowered balloons and powered airships. A balloon may be free-flying or tethered. An aerostat's main component is one or more gasbags, a lightweight skin containing a lifting gas to provide buoyancy, to which other components such as a gondola containing equipment or people are attached. Especially with airships, the gasbags are often protected by an outer envelope. One of the most recent deployments of an aerostat was seen at the opening ceremony of the nineteenth 2010 Commonwealth Games, held in Delhi, India. The aerostat used in the ceremony was the largest in the world.