A Common Bus Structure for Avionics and Satellites (CBSAS) (10) as shown in FIG. 1 is comprised of a module lid (14), module floor (38), module stack base (16), module compression bolts (22) and stackable modules (12). Stackable modules (12) are sub-dividable to create module scaled chamber volumes (45) individually as required, while stackable modules (12) simultaneously create at least one collectively continuous raceway sealed chamber volume (44) perpendicular to individual stackable modules (12) in the vertical direction where no module floor (38) is present, in order to internally electrically interconnect the contents of any stackable module (12) with the contents of any other stackable module (12) via internal connector raceway system (24). Raceway sealed chamber volume (44) therefore collectively and continuously traverses all present stackable modules (12) positioned between module lid (14) and module stack base (16). Modules are interchangeable and inter-connectable in any order, and contain all required electronic or mechanical components required for CBSAS (10) to function as a single box consolidated avionics system that is equally functional in the atmosphere or the vacuum of space, while also being fully functional as a single complete stand-alone satellite system. CBSAS (10) enables a paradigm shift in the aerospace industry whereby all legacy and current multiple black-box systems on aerospace platforms such as missiles, rockets, satellites and aircraft are extremely inefficient when compared to the size, weight and power attributes of CBSAS (10). The ability for CBSAS (10) to be instantly employable as either a single box consolidated avionics system for use within the atmosphere or in space while also being fully functional as a stand-alone satellite enables a hardware, firmware and software capability never before manifested in the aerospace industry.