The rocket tests carried out after the Second World War were the forerunner to space travel. A Soviet sputnik was the first satellite to be placed in orbit in 1957 and the first manned space flight was undertaken by the Russian Yuri Gagarin in 1961. Thanks to low density coupled with high strength, aluminium and its high-strength alloys have been the main materials used since space travel began, (although composite materials are increasingly being used as in aircraft construction):
- They are used as structural parts and fuel tanks in carrier rockets, space orbiters and space probes.
- Aluminium powder is the main constituent of the fuel in solid-fuel rockets, such as those used during takeoff of an American space orbiter.
- Aluminium-based materials are also used for load-bearing parts in satellites and space stations, supports for solar cells, test equipment and insulation (air conditioning technology).
Researchers are striving to develop new aluminium-based materials with even greater strength and lower weight:
- In metal matrix composite (MMC) technology, aluminium alloys are strengthened by embedding particles such as boron or silicon carbides in them.
- In aluminium"lithium alloys, there is a six per cent increase in strength for every one per cent of lithium; the density decreases by three per cent. Using conventional casting technologies, the maximum solid solubility of lithium is 4.2 per cent; significantly larger solubilities are possible using Rapid Solidification Processing (RSP) technology, thanks to the very fine grain structure.