The use of art to explain (and sell) scientific research and the space program was pervasive in its early days, an extension in some ways of the pulp illustrations of sci-fi magazines and book covers of the previous decades. What would a space station look like? How about the Martian landscape, with or without a potential landing craft?
That visualization tie has largely faded away, as actual space photography has replaced some of it, the art world pooh-poohs representational art (esp. for "propaganda" purposes), and budget-cutters have decried artistic commissions by NASA as wasteful.
The result is a loss of some of the best ways of both portraying — and, yes, selling — the excitement of the as-yet-unglimpsed.
The Slow, Tragic Death Of Space Art
The huge, hidden cost to severing the bond between art and science.
The art in the PC/PS4 game No Man's Sky seems to have been strongly influenced by pulp cover art. Google some and see what you think.