Captain's Log Solo Roleplaying Game is new from Modiphius (which produces the official Star Trek Adventures TTRPG). The digest-sized rulebook is 326 pages long, and you play a starship captain as your ship and crew explore the galaxy.
The game is set in any era of Star Trek, from TOS all the way through to Discovery in the 32nd Century, Missions are randomly generated, as there is no gamemaster, but the game can also be played cooperatively with a GM.
The book comes on in August, but if you pre-order now you get the PDF immediately.
StarTrek.com has a preview of the game.