*2.3.2 Standard SpaceWire data bus*

SpaceWire (SpW) is an industry standard with protocol derived from IEEE-1355 and ECSS-E50-12C managing by the international SpW working Group [18, 29, 30]. The SpW standard is a self-managing serial protocol that provides a high-speed data rates from 2 to 400 Mbps, and low power serial interface using LVDS<sup>1</sup> Drivers with distances up to 30 feet while offering a flexible simple user interface. **Figure 6** illustrates typical uses of SpW data Bus with a PCD&HS, a SpW Router and SpW cables for connecting mission PL components. Some examples of existing satellite programs employed SpaceWire standard are: TacSat (part of the U.S. Operationally Responsive Space Program), NASA Lunar Reconnaissance Orbiter (Orbiting the Moon taking high resolution images), ESA Sentinel-3 (a pair of satellites providing operational Earth observation services using optical and microwave instruments), and Japanese NEC NEXTTAR (one of the first spacecraft designed using SpW for all of its onboard communications).
