Thinnest manned spacecraft hull

The lunar modules of the US Apollo program were the only true spacecraft designed solely for flight in space. For landing on and leaving the airless Moon, no aerodynamic qualities were necessary in their design. The 'skin' of the crew compartment was only 0.3 mm (0.012 in) thick – equivalent to several layers of aluminium kitchen foil. However, this thickness of aluminium alloy was sufficient to maitain the integrity of the hull when pressurised to contain a breathable atmosphere. Some astronauts likened it to a metal balloon. The lunar modules were built for NASA by Northrop Grumman (USA).