When Neil Armstrong, Buzz Aldrin and Michael Collins set off on the first manned moon landing in 1969, they had a laser retroreflector on board. The device still stands on the moon today and makes it possible to measure the exact distance between Earth and Moon. High-tech fused silica from Heraeus made this reflector possible. More infos on the retroreflector and various space missions can be found at apollo-11.com.