Exotica Research | Music from Outer Space

Ken Saari's historical survey on space age pop from 1940s through early 1960s is worthwhile, and also includes many higher resolution album cover scans.

From Saari's article:

Nothing represents "space age pop" more literally than music with an explicit outer space theme, or "outer space exotica." Music in this genre, typically of the instrumental variety, was arranged for several LP record albums from the late 1940’s through the early 1960’s. In general, the most successful examples contain adventurous arrangements of music written especially for the album. Often, electronic instruments and other novel effects are present, and these sounds are integrated effectively into the music. The least successful albums typically have some electronically generated sounds, but are otherwise lackluster compositions or mundane, syrupy renditions of popular standards with celestial titles like "Star Dust" and "Out of This World." Whether the music in the record grooves is inspired or dated, the album cover jackets typically feature imaginative period artwork and are collectable in themselves.

http://www.ele-mental.org/~ecc/exo/exotica/osearticle.html