On the Development of Spacecraft Operating Modes for a Deep Space CubeSat

In contrast to technology demonstration missions, very small spacecraft (also known as CubeSats) conducting a science experiment often require multiple carefully designed operating modes. These modes are typically driven by power and communications budgets, and by the specific requirements of the science payload itself. The design constraints levied on these operating modes become more stringent for CubeSats operating beyond low Earth orbit, as all of the attendant subsystem budgets become stretched even further. This paper will discuss the design of the operating modes for the BioSentinel spacecraft, a six cube CubeSat that will be deployed into an Earth-leading, heliocentric orbit after tip-off from the Space Launch System. The nature of the science payload, combined with the challenging subsystem constraints that are typical of CubeSats, necessitates the design of multiple distinct spacecraft operating modes to ensure mission success.