No abstract

A new class of low-cost satellites has the potential to reduce the cost of traditional space-based services. Unfortunately, to date, low-cost satellites have proven to suffer from poor reliability. While traditional techniques for increasing reliability are well known to satellite developers, these techniques are poorly suited for implementation on low-cost satellites due to intrinsic budgetary, mass and volume constraints. This research proposes that alternative techniques for increasing system reliability can be derived by studying biological organisms, which have proven their robustness by inhabiting even the harshest locations on earth. Both unicellular and multicellular organisms are examined. The result is a conceptual system architecture, based on initially identical, reconfigurable hardware blocks, or artificial cells, and a decentralized task management strategy. This multicellular architecture is described in detail. Finally, preliminary details of a planned implementation are given. This implementation aims to demonstrate that a significant portion of traditional satellite avionics can be replaced by the proposed artificial cells

While small, low-cost satellites continue to increase in capability and popularity, their reliability remains a problem. Traditional techniques for increasing system reliability are well known to satellite developers, however, their implementation on low-cost satellites is often limited due to intrinsic mass, volume and budgetary restrictions. Aiming for graceful degeneration, therefore, may be a more promising route. To this end, a stem-cell-inspired, multicellular architecture is being developed using commercial-off-the-shelf components. It aims to replace a significant portion of a typical satellite's bus avionics with a set of initially identical cells. Analogous to biological cells, the artificial cells are able to differentiate during runtime to take on a variety of tasks thanks to a set of artificial proteins. Each cell reconfigures its own proteins within the context of a system-wide distributed task management strategy. In this way, essential tasks can be maintained, even as system cells fail. This paper focusses on two hardware implementations of the stem-cell inspired architecture. The first implementation, based on a single cell, serves as the Payload Interface Computer on a CubeSat named SME-SAT. The second hardware implementation is a benchtop system composed of several cells intended to demonstrate a complete multicellular system in operation. In order to demonstrate the feasibility of these multicellular architectures, the physical attributes of the hardware implementations are compared to those of more traditional implementations and are shown to have enhanced reliability at the cost of increased power and internal bus bandwidth.

Abstract-Low-cost satellites continue to grow in popularity and capability, but have shown poor on-orbit performance to date. While traditional satellite missions have relied upon expensive fault prevention techniques, such as component screening, the use of radiation hardened components, and extensive test campaigns, low-cost missions must focus on fault tolerance, instead. This paper describes a novel, fault-tolerant system architecture, named Satellite Stem Cells. The Satellite Stem Cell Architecture, which is based on artificial cells, evolved from research into traditional reliability theory, bio-inspired engineering, and agentbased computing. Traditional reliability theory points towards k-out-of-n architectures for their superior reliability, while cell biology demonstrates how to build extremely multifunctional subsystems. Finally, agent computing provides a solution for facilitating the cooperation of a set of autonomous cells in a peer-to-peer environment. This paper describes the development of the architecture, details the artificial cell design, and gives preliminary implementation details.