Highly-miniaturized spacecraft “PlanarSat”: Evaluating prospects and challenges through a survey of femto & atto satellite missions

As satellite technology advances, there has been a notable trend towards miniaturization, leading to the development of increasingly smaller satellites such as femtosatellites and attosatellites. A new emerging form of such satellites is often called ChipSat, with unique designs that utilize both surfaces of a single plane to maximize functionality within limited dimensions. Initially, the term ChipSat referred to system–on–a–chip satellites but it has since expanded to include centimeter and millimeter scale spacecraft. To provide a clearer terminology, this paper introduces the term “PlanarSat” for such a planar spacecraft. Despite the challenges in deployment and the constraints, such as cost, size, access to space, and capabilities, of miniaturized subsystems, these satellites represent a significant shift in space technology, aiming for cost-effective solutions and innovative mission capabilities. This study reviews thirty sub-100-gram satellites, analyzing their design, deployment, and potential for future advancements in a comparative manner. In this study, satellite independence was defined based on system-wise independence, highlighting operational autonomy irrespective of physical connections. The survey's findings highlight technological advancements and potential applications for these very small spacecraft, which are pushing the boundaries of what is feasible with smaller satellites and how these satellites were or planned to be delivered to orbit. The analysis results provide a basic cost comparison, providing information on hardware and launch costs, taking the instantaneous data rate as a reference point, underscoring the need for a new systems engineering approach to the design of such satellites.