One of the key Clement Sector & Earth sector books is 'Unmerciful Frontier: The CCA Sourcebook Third Edition' by John Watts. And its a key book if we're using the Space Western analogy and the key reasons are in the description; "Unmerciful Frontier covers the Cascadia Colonization Authority, the most famous of many organizations in Clement Sector dedicated to scouting the unknown and determining where future colonies might be placed. Unmerciful Frontier gives detailed descriptions of the CCA and features career tracks to allow your players to become members of this storied group."
Unmerciful Frontier also features our advanced star system generation method which is updated to match the best science available concerning the topic. Unmerciful Frontier's star system generation method will return realistic star systems usable with any science fiction game.
The book also acts as a sourcebook for Tranquility Sector, the sector directly to trailing of Clement Sector and a prime location for adventure."
The reason why I'm saying that the 'Unmerciful Frontier: The CCA Sourcebook Third Edition' by John Watt is because this book gives all of the details on creating the further edges of the terrorities of the Clement sector and its ilk. This book gives us deep details on the Tranquility sector & this is the last green dot of civilization before the 'no man's land' that is the Clement Sector's deep black of interstellar space. This book details those explorers, far searchers, scouts, & deep spacers. These are the individuals who brave the deepest depths of space without the furthest idea of what's out there. And the 'Unmerciful Frontier: The CCA Sourcebook Third Edition' by John Watt is the book that gives the DM the tools to create what's around the next solar system.
And one of the key adventures for the CCA?! Well that's Hell's Paradise by George Ebersole & it goes deep into what makes the CCA so dangerous and well rounded for adventure creation.
You've got exploration, 'save the crew' tropes and more; "TXE-605b, known to some as Calliope, is an untapped planet whose barren surface but breathable atmosphere and abundance of water promises to be an excellent candidate world for colonization. The Nordic Exploratory Service sent an expedition to the TXE-605 system to expand humanity's knowledge of this world. Now their vessel, NESS Arn, has not returned on schedule. The crew of the CCAS Clara Barton, a Cascadia Colonization Authority search and rescue ship, has now been tasked with finding out why the Arn has not come back from TXE-605b. Have they been attacked by pirates? Have they suffered a malfunction? Or is it something far more sinister? "
Everything about Hell's Paradise works because it tapps deep into what makes the CCA great. You've got the crew of a search and rescue ship going in deep into the black to find out the fate of an NES ship's crew on an unknown planet. Lots of opportunity for bringing in the adventure & horror elements if the DM wants to. But there's multiple opportunities for the player's PC's to leave their mark on the expanding frontier themselves. There's a deep dictomy of exploration & to a certain extent exploitation of the interstellar scene as it stands in the Clement sector and that's expanding. The CCA is one of the most undersung adventure opportunity elements of the Clement Sector rpg in my opinion. They have deep roots in what makes the Clement sector work as an adventure setting.
Unmerciful Frontier: The CCA Sourcebook Third Edition By John Watts For the Clement Sector rpg Is Available Here.
Hell's Paradise By George Ebersole For the Clement Sector Is Available Here.