What material is used to make spacecraft?

So far as an astronomer understands the ‘witchcraft’ of spacecraft design, very light weight and durable alloys of titanium, aluminum and magnesium are commonly used. This picture of the ISS shows many different materials that have to be made space-worthy to survive the extreme conditions of temperature and pressure. (Credit: NASA: STS-132). Aluminum – Most commonly used conventional material (used for hydrazine and nitrous oxide propellant tanks). Low density, good specific strength. Weldable,.