1971, when we even had cool cars driving on the moon (it's still up there you know, just needs new batteries)

and we had cool 2 piece stamps. By the way, I photoshopped the cancellation mark off the top stamp.

This issue was designed by Robert T. McCall of Paradise Valley, Arizona. https://en.wikipedia.org/wiki/U.S._space_exploration_history_on_U.S._stamps

By the way, if you want a time machine back to the early 70s, just look down through http://www.apnss.org/Eight-centCommems.htm