Some aluminium alloys have good low temperature performance and are not cold and brittle at - 183 ~ - 253 [2oc]. They can work in liquid hydrogen and liquid oxygen environment. They can not react with concentrated nitric acid and unsymmetrical dimethylhydrazine and have good welding performance. Therefore, they are good materials for liquid rockets. Saturn 5 launch vehicle launching Apollo spacecraft is made of aluminum alloy at all levels of fuel tanks, oxidizer tanks, inter-tank sections, inter-stage sections, tail sections and instrument cabins.