dragoner
KosmicRPG.com
Wild Bee at itch.io
dragon3r - itch.io
It is also GM's day sale at dtrpg DriveThruRPG.com - Wild Bee Publishing - The Largest RPG Download Store! and both titles are 30% off (I have set the price on itch accordingly).
Solis People of the Sun, over 30 star maps of 550 of the nearest star systems, including a detailed index of stars with xyz coordinates so that it can be used with an online 3D distance calculator.
Andromeda Dragons further detailing the universe with 44 star systems, plus sections on Space Battles of the Unity War, a starship, and pre-generated characters or non-player characters.
A woman from Japan recently wrote that she uses the game with her 9 year old daughter to teach about stars, and they use VR head sets as to tour different star systems. Her daughter likes it a lot.