More resources and guidelines for making and running adventures in humanity’s cradle.

Sol system is out in PDF and a print-version can be pre-ordered, and more exciting Expanse roleplaying game news have been announced!
As the book just dropped I’ve only had time to skim through it, but so far, this is what I’ve found.
It is divided into five chapters, plus an introduction and appendix.
Chapter 1 politics, crime, movers and shakers
This chapter makes up about a quarter of the total pagecount (pages 5 through 32), and it covers a lot. From the three governing organisations, to megacroporations, smaller corporations, and a slew of crime syndicates, inlcuding ones we know from the books and GRP’s published adventures. While Earth and Mars have relatively small entries in this chapter (expanding on their more lengthy entries in the core rulebook), there is expansive information on several factions of the OPA (Voltaire Collective, Tycho, Union, and more), including information about leaders, rivals, connections.
Megacorporsation include information on Pope Enterprises, Star Helix, Mao-Kwik, Bush Orbital Shipyards, and several more. Each entry has generally known information, but also lists rivalries, competitors, subsidiaries, and more, including story hooks. Smaller corporations have shorter entries with just enough information to give an idea to work from, providing ideas and names for potential antagonists or business opportunities.
The list of crime syndicates is long. Similarly to Megacorps, these entries provide general information, rivals, and story hooks. Golden Bough Society, Loca Greiga, Orn Aquilo, and several more, it is a menu of troublemaking organisations that can be hazards, customers, employers, allies and nemeses to your group of players.
The first chapter rounds off with religious groups, humanitarian aid groups, political activists, and those who live on the fringe.
Chapter 2 space stations
This chapter (pages 33 through 56), provides names of and brief information about several notable Sun-Earth Lagrange point stations, including a sidebar on a few other Lagrange point stations. Ceres and Tycho follow, each with a good chunk of information about inhabitants and features, including cross-section maps. These two sections offer a lot for groups and GMs that want to explore these two stations further. The chapter ends with a list of smaller stations.
I have only briefly looked through this section, it is somewhat more focused than chapter 1, with it narrower focus, and thus higher information density. I foresee this to be very useful for some, and perhaps less useful for others.
Chapter 3 business, shipping, and trading
This chapter (pages 57 through 76) gives GMs and players information on hauling, taxation, and expanded rules on different ways to acquire cargo, ship cargo, and buy and sell cargo. It includes trading routes, several tables on exports and imports of most big and relevant ports and planets, information about the realities of piracy (heists, getaway, and selling the swag) and smuggling. These are good and importants additions and expansions to the rules introduced in Ships of the Expanse. This, I dare to speculate, is what many have been waiting for. It can be useful for a group of players wanting to do shipping, or if they want to be pirates.
I have only glanced the the rules expansions, but they follow in the spirit of other Expanse and Modern AGE expansions, in that they are simple, abstracted, and fast, yet they provide details that you may (if you so desire) expand upon and make more detailed. They may easily be used during play, but may perhaps be better utilised as part of prepping an adventure.
The “Trade Goods” section includes more information on Mercury, Earth, Mars, Ceres, the Jovian and Saturnian systems, Tycho, Uranus, and Medina station, and a brief mention of trade beyond the ring.
Chapter 4 planetside business
Chapter 4 (pages 77 through 95) offers guidelines on planning campaigns (or adventures) on the streets of Earth and Mars, but also the corridors of space stations, or on the streets of a settlement in a star system far from Earth. It includes various variants or themes of such stories. From Espionage to Corporate Interests to After the Fall, and more.
It also includes suggestions for starting points during the Earth-Mars conflict, the exodus after the ring opens, and during The Free Nacy Conflict.
The chapter’s “series frameworks” section is filled with story hooks for the various types of frameworks outlined: Streets of Earth, Red Planet, Academy Days, Corporate, Media, and more.
This chapter is an incredible resource for GMs that is looking for frameworks and guidelines when they want to set a campaign on a planet, a city or large colony. Easily combined with or influenced by the offerings of Beyond the Ring to create an interstellar campaign.
Chapter 5 orgs and cults and politics
The shortest chapter (besides the introduction), the fifth chapter introduces rules on organisations. Much like colonies or settlements in Beyond the Ring, organisations have stats and focuses, can undertake operations (projects with rewards), grow (stunts!), and be destroyed due to threats. These rules are perhaps best suited for groups that want to deal with the added burden of running an organisation, the politics, conflicts, and bounties that may follow. However, a resourceful GM may find ways of utilising this without increasing book keeping, just adding fun and intrigue to the game.
In Sum
This appears to be a solid expansion of both lore and rules, a GM is certain to find something of use in this book, inspiration, lore, rules, ideas, story hooks, and more. Definitely a good addition to the game.