Responsive space plug & play with the satellite data model

Abstract

The Satellite Data Model (SDM) is a middleware system providing fault-tolerant Plug & Play features for the Responsive Space program. Using the SDM middleware, a flight system supports not only Plug & Play for devices, but also auto-configuration of pre-written applications and a degree of fault-tolerance for hardware failures. The SDM is based upon a variation of the publish/subscribe distributed systems model. Utilizing SPA-U or SPA-E communications links, devices are auto-detected by the SDM system when connected or powered up. Applications are detected by joining the SDM system. Upon detection, each device or application is queried by the SDM for a complete description of its data producing capabilities, controls, and data messaging formats. The SDM utilizes the xTEDS description language to express this information. Applications requiring certain data or services may query the SDM for appropriate producers or providers. The SDM returns appropriate matches and xTEDS data product message descriptions in response to the application query. The application may then subscribe to a producer that most closely matches its data needs and formats.