Spacewire

Spacewire is a high-speed, low-latency point-to-point serial data-bus standard designed for use in space applications. Developed by the European Space Agency (ESA), it is intended to interconnect electronic units within a spacecraft, such as processors, memory modules, and sensor interfaces. The standard defines the physical layer, data link layer, and a basic transport mechanism for transmitting data packets.

The Spacewire standard is characterized by its simplicity, robustness, and low power consumption, making it suitable for the harsh environment of space. It uses differential signaling over shielded twisted-pair cables to achieve reliable data transmission in the presence of electromagnetic interference. Spacewire operates at speeds up to 200 Mbps per link, and multiple links can be connected to form a network.

A key feature of Spacewire is its deterministic nature, which is crucial for real-time control systems in spacecraft. The protocol supports both unacknowledged and acknowledged data transfers, allowing for different levels of reliability depending on the application's requirements. Error detection is provided through cyclic redundancy checks (CRCs).

Spacewire has been widely adopted in many space missions, including those by ESA, NASA, and JAXA. Its widespread use and proven reliability have made it a de facto standard for onboard data handling in a significant number of satellites and space probes. The standard is maintained and updated to incorporate advancements in technology and evolving mission needs.