space age

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The period after 1957, the year in which a spacecraft was first placed in orbit around Earth, marking the beginning of space exploration.

from the GNU version of the Collaborative International Dictionary of English.

• noun 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The period from the about the time of the launch of Sputnik in 1957 to the present day, during which man ventured into space.
• noun attributive Redolent of the space age; appearing futuristic or modern.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the age beginning with the first space travel; from 1957 to the present