OpenOrbiter Mechanical Design: a New Approach to the Design of a 1-U CubeSat

The OpenOrbiter Small Spacecraft Development Initiative is working to create a set of designs and implementation instructions for a 1-U CubeSat, called the Open Prototype for Educational NanoSats. These designs target a total parts cost of below USD $5,000. This design will be made publically available to facilitate its use by others, with or without modification. A ‘side slotted’ CubeSat design (where main circuit boards are placed in slots between the rails on the outside) has been developed for OpenOrbiter. This paper discusses the design choices that were made during the mechanical structure development of the OpenOrbiter CubeSat design, required to keep it within the mass, volume and monetary budgets. Choices like the design of the aluminum support structure, fastener mechanisms, circuit board layout and science package support structure are all discussed and their ease of construction and efficacy are considered. A discussion of ongoing work on the spacecraft’s mechanical fabrication and other subsystems is also presented. The paper also discusses how the design can, prospectively, be utilized by others and the ‘bigger picture’ benefits provided by the design approach and open hardware concept.