Star Frontiers is a SF RPG of the Space Opera type released by TSR in 1982. It used a system with only D10, with skills rated on a percentile system (roll under 1D100). TSR published the first of 3 extensions called the ‘Zebulon’s Guide to Frontier Space’ which started a change of the system, but the planned two other books in the series were never published. Still it was a very fun game, with weird alien races that you could play (Dralasites, Vrusks, Yazirians). It has a significant fan base that still publishes regular magazines and material for the game, although they were recently told that they could not publish anymore and that stirred rumors that a new edition migh be in the work.
I made a map of the known Frontier way back.
And I also made a character sheet.