Application of Titanium on U.S. Spacecraft-II

"Apollo" spacecraft. This ship is similar to the lunar exploration project Chang'e 5 launched by the China Space Administration in 2020. However, Chang'e 5 was not manned, and "Apollo" sent people to the moon, landed on the surface of the moon, and then returned to Earth. It consists of a spacecraft hull and a large "Saturn-V" rocket. The spacecraft has a mass of 50t and a rocket mass, about 2900t. 

The spacecraft contains a command cabin with a volume of 7.65m3, a mechanical cabin and a lunar module. The spacecraft and the rocket structure shared 68t of processed titanium. All brackets, fixtures and fasteners of the spacecraft are made of titanium. The command module, the mechanical module and the lunar module shared 1190kg of titanium.

The tower structure of the launch traction system is made of titanium alloy, and the liquid hydrogen containers and ducts of the command cabin and the mechanical cabin, and the cryogenic container of the lunar module are all made of Ti-6Al-4V alloy. The lower part of the lunar module container needs to have greater plasticity, so it is made of Ti-5Al-2.5Sn alloy. The "Apollo" spacecraft has more than 40 pressure vessels, of which about 85% are made of titanium alloys, and Ti-6Al-4V and Ti-5Al-2.5Sn alloys are used to make dinitrogen tetroxide, helium, nitrogen and fuel vessels. Because Ti-5Al-2.5Sn alloy has high toughness at -252.7°C, liquid hydrogen and supercritical helium containers are made of this alloy.

The space shuttle is a means of communication between the ground and the space station, so it is also called a space ferry. It needs to be used multiple times, preferably 100 times or more. When it enters the atmosphere, the upper half of its fuselage and wings. The temperature can reach 180℃～815℃. Therefore, some parts of the components need to be made of heat-resistant titanium alloys, such as Ti/B-Al composite materials for the upper fuselage frame, and the tail, wing beam and ribs. 

The hydraulic piping is made of titanium alloy, and the oil pressure piping is Ti-3Al-2.5V alloy seamless pipe, which reduces the quality of the system by more than 40%. In order to reduce the sensitivity to fatigue fracture and improve the service period of the system, various pipe fittings. Both forming and assembly are automated.