Technically the Space Age is the period of time beginning in 1957 (when the first spacecraft began to orbit the Earth) to the present.
The term Space Age has become overused -- much like the state of the art. Thousands (and probably hundreds of thousands) of products have claimed to be "space age designs" or made from "space age materials". The space age claims aren't solely for electronics as you might suspect -- now we have space age food, space age knives, space age cleaning fluids, and even space age credit unions.
At one time attaching the phrase to a product might have brought some mystique and further interest. Nowadays it's almost laughable. Space age materials and technology can be up to 45 years old. What's so new and exciting about that?