According to a post on the Catalyst Game Labs Battlecorps web site, they have just released the Strategic Operations PDF.  Strategic Operations is the fourth core rulebook beyond the Introductory Box Set.  Beyond the standard rules, a set of advanced rules exists, allowing players to expand their games in any direction they desire.  Strategic Operations stages up play from the planet to the entire solar system.  Linked scenarios and Maintenance, Salvage, Repair, and Customization Rules enable players to build any type of campaign they wish.  It includes rules for transporting troops between worlds and combat rules to protect those troops as they combat drop onto a new target world.  For more information, see the Battlecorps web site.

A print version of this product will appear at a later time, according to the web site.