How do you divide up the Space Age?
OK, it's obvious that the first period of the Space Age lasted
from October,04,1957 to July,20,1969.
The second period is less obvious.
I think it lasted from July,20,1969 to April,12,1981.
The third period could be from April,12,1981 to January,28,1986.
The fourth period could be from January,28,1986 to January,31,2003.
The fifth period could be the one we are in now.
That's my take, you might have your own.