Here are some links you might find interesting.
Project Rho spaceships, planets, FTL, etc. Not a secure site.
My Traveller site has over 1,000 planet maps, a number of solar system maps, and files detailing solar systems. There are a number of sector maps, and sub-sector maps.
Not as many maps.
my Star Frontiers site
And if you need D&D type maps.
Crest of a Star