Multi-purpose Module Footprint
The CubeSat Kit Motherboard in Slot 0 forms the base of a stack of interconnected modules above it. The CubeSat Kit Bus -- which normally begins on the Motherboard as a non-stackthrough connector -- connects all of the user modules Slots 1 upwards to the Motherboard. All user modules share the same layout. Normal inter-module height is 15mm. With an additional floating connector, larger inter-module heights (e.g., 25mm) can be reliably achieved. Smaller inter-module heights can be achieved through the use of alternate, higher-density connectors, based on user designs with aletrnate connectors.
Motherboards can be ordered with an optional, alternate, stackthrough connector, thus allowing user modules to be mounted in locations other than Slot 0. This is typically used in CubeSat Kits larger than the standard 1U (10x10x10cm) format or in CubeSat Kit payloads, and provides maximum flexibility in locating payloads and other CubeSat components within the stack of modules.
PC/104 Compatibility
PC/104 modules can be mounted within the CubeSat Kit structure because all the modules employ the same mounting points and overall dimensions (nominally 90x96mm). PC/104 modules that mount directly above or below the Motherboard can derive +5V and GND via optional PC/104-style connectors located on the Motherboard. PC/104 modules located further away from the Motherboard can be powered and interconnected via user modules that employ both the PC/104 bus and the CubeSat Kit Bus.