I watched a documentary about the the NASA voyager mission in 1977. The outer planets were aligned in way that only happens every 175 years or so. They had to get it exactly right and they did. 

The guy being interviewed had worked on it his whole life. The mission ended in the 80s but Voyager is still travelling. It still sends a faint signal back to earth. 

He went to work every day, even though retired, to listen out for Voyager and check it was ok until he was very old. It was very emotional.

He is now dead. Voyager still travels.

That will be Bitcoin retirement.