Interoperability and rapid spacecraft development using SpaceWire Plug-and-Play

SpaceWire is rapidly becoming a de facto communications standard within the space industry. SpaceWire represents a suitable point of convergence for data communication onboard spacecraft due to its simplicity, speed, low-power and reliability, providing the basis for interoperability between devices and components from different manufacturers and organisations. True interoperability of SpaceWire devices is not possible without the standardisation of various functions offered by the draft SpaceWire Plug-and-Play standard. SpaceWire Plug-and-Play offers a number of benefits to SpaceWire networks including a standard method for discovery and verification SpaceWire networks which could provide invaluable support to FDIR mechanisms, EGSE and routine spacecraft operation. The standardisation offered by SpaceWire Plug-and-Play increases the potential for hardware and software reuse which creates a market for commercial-off-the-shelf components; a market which is accessible to smaller organisations with expertise in key niche areas, such as instruments and onboard computers. This paper presents the aims and driving forces behind the development of the SpaceWire Plug-and-Play standard so far, reviewing recent progress. The last year has seen some major changes to the SpaceWire Plug-and-Play draft standard, including a move to build the protocol on top of an existing standard: the Remote Memory Access Protocol (RMAP). The details of the SpaceWire Plug-and-Play draft standard will be presented, described in the context of use cases, showing how the various features of the protocol can be put to practical use. The paper will conclude by considering the position of SpaceWire Plug-and-Play in a wider context: discussing the potential impact of interoperability of the development and deployment of spacecraft, and the commercial market for spacecraft components.