In the civilizations of Earth, during the fifties and sixties, the Soviet Union and the United States entered into a state of Cold War, with various new weapons emerging one after another. Many pieces of equipment that are well-known to people were born in this period.
During this time, missiles began to mature, and various technologies also started to stabilize. Many weapons became classic and could be used for a long time.
For example, the Hercules Transport Aircraft is one of the more classic planes: it has continued to be in service until the new century, and still stands strong without much issue.
Another classic is the United States' B-52 Stratosphere Fortress Bomber, which is also a classic bomber that has been in use for seventy years.