1. the age beginning with the first space travel; from 1957 to the present;
The Collaborative International Dictionary of English v.0.48:
Space age \Space age\, n.
the time during which humans engaged in space exploration; --
generally considered as beginning on October 4, 1957 when the
Soviet Union placed the first artificial satellite into orbit
around the earth.
[PJC] space bar
WordNet (r) 3.0 (2006):
n 1: the age beginning with the first space travel; from 1957 to