There is a definite influence from Star Wars/Battlestar Galactica not only in some clothing, but in the ubiquitous red stripe on vehicles.
The classic Flash Gordon/Buck Rogers aesthetic can be clearly seen in the early art and fashion, with a good dose of 1950s/60s classics like Forbidden Planet and Lost in Space; the robot art is particularly influenced by this.
Then there is the Old West aesthetic that can be found in some of the very early artwork.
Later modules have a strong Space: 1999 influence in their artwork (particularly the UK ones), as well as from Alien... but most sci fi of the era was heavily influenced by that aesthetic.
I surrender! Actually, I didn't know about those or hadn't consciously processed them. I was talking about the homages to Space Academy (the Plannarion asteroid belt pirate base), The Gil Gerrard Buck Rogers (same image) and Gene Roddenberry's failed Planet Earth pilot.
The other influence I detect (though I'm not 100% certain of is a bit of Heavy Metal (the magazne/movie) in some places. Oh, and DSOTM feels a lot like a Bond movie.