The exploitation and exploration of space opens the door to improvements of life on earth, new discoveries and new research opportunities. However, space flight also provides a unique range of challenges due to the harsh environment and difficulty in maintaining systems. Safety, fault-tolerance, and availability are key to ensuring successful missions – both for unmanned vehicles and in human space flight.
Modularity and scalability can save cost and reduce complexity in spacecraft avionics. This is especially important in large projects such as NASA’s Gateway, where different space agencies and a large ecosystem of suppliers work together on the next generation space station. To ensure seamless data transfer and connectivity of the Gateway modules, NASA and their international space agency partners have baselined the Time-Triggered Ethernet networking technology based on the open standards Ethernet IEEE 802.3, ARINC 664 and SAE AS6802 in the “International Avionics System Interoperability Standards” (or IASIS) for deep space avionics applications.
Advantages of Deterministic Ethernet communication
TTEthernet is an open, standardized technology. It is based on standard Ethernet (IEEE 802.3) and adds two deterministic traffic classes (ARINC 664 part 7 and SAE AS6802) or quality of services to its implementation. As deterministic data transfers are characterized by predictable jitter and guaranteed transmission latency, they are ideal for use in real-time functions and the set-up of safety-critical systems.
The interoperability of TTEthernet with standard Ethernet provides more flexibility in applications, while allowing the use of a single network for transmission of command and control as well as payload data. This simplifies spacecraft avionics and with bandwidths up to 1 Gbit/s, TTEthernet can also support applications that demand high speed or large amounts of data.
The TTEthernet network acts as the ‘central nervous system’ of the space station/spacecraft and takes over all communication tasks, not only within the individual modules, but also between the elements of Gateway and docking spacecraft and/or landing systems.
Mature solutions for integrated, modular, and scalable data networks in space
TTTech Aerospace offers reliable, space qualified equipment and integrated platform systems for Deterministic Ethernet networking applications for deep space exploration missions.
“Our TTEthernet products have been designed to the highest space standards, always keeping scalable, safety-critical, high-performance spacecraft avionics systems in mind. The related products are available in different quality levels to support the entire development process during spacecraft design and integration: EDU (engineering model for development and functional verification), PROTO (populated with qualifiable engineering units), and FLIGHT (qualified units for flight use in deep space). Customers can start with the EDU version offering the full functionality for evaluation or in the development phase and seamlessly move to the PROTO version to be fully form-fit and function compatible with the final FLIGHT version. This approach allows a cost-efficient and technically straight forward development,” explains Christian Fidi, Senior Vice President, Business Unit Aerospace at TTTech.
To answer the growing need for modular networked computing platforms for space, TTTech Aerospace and its space hardware partner RUAG Space have joined forces and developed COTS products/systems that can be integrated into a hosting unit by customers. These are already being used for two of Gateway’s modules, Northrop Grumman’s Habitation and Logistics Outpost (HALO) and Maxar Technologies’ Power and Propulsion Element (PPE).
The core of these products/systems is a highly integrated ASIC developed by TTTech Aerospace based on a radiation hardened silicon library and process, which together with additional design technics implemented by TTTech Aerospace leads to a highly reliable space grade building block. This ASIC acting as switch and end system is integrated into space hardware modules and platforms together with RUAG Space. The first form-fit and functional equipment of this product line was delivered to Northrop Grumman and Maxar Technologies in summer 2021. It will allow the customers to start early development on flight-like equipment and ensure a seamless integration towards flight products.
This space hardware is based on a modular 3U cPCI form-factor where the avionics hosting unit developed by TTTech Aerospace and RUAG Space can accommodate up to four modules (switches or end systems) and has two redundant power lines. It was especially designed for the 3U cPCI form factor and has a modular design that allows it to be extended modularly, giving customers more configuration flexibility.
Deep expertise in reliable data transmission and TTEthernet equipment for space
Apart from NASA’s Gateway, TTTech Aerospace is also on board in other space projects for Moon and space exploration. The NASA Orion Multi-Purpose Crew Vehicle (MPCV) and Ariane 6 are two reference projects that use TTTech Aerospace’s technology and products.
Since 2008, TTEthernet has been used as the central avionics communication system in the NASA Orion MPCV. For this project, NASA cooperated with the European Space Agency (ESA) and ESA delivered the European Service Module (ESM). The Orion MPCV and the ESM are connected and integrated with TTEthernet. After its first successful flight in December 2014, the Orion MPCV is now part of the Artemis I mission and will complete its next unmanned test flight on the Space Launch System (SLS) in the near future. After that, crewed test flights will be carried out.
TTTech Aerospace’s network ASICs can also be found in the avionics system of the Ariane 6 launcher. They are based on TTEthernet technology and comprise the complete logic required to establish highly reliable data communication. The project was started in 2016 and TTTech Aerospace has now completed the main development phase and the qualification of its components. The first flight of Ariane 6 is scheduled in the first half of 2022.
TTTech Aerospace offers a complete TTEthernet product portfolio for space that spans the customer program lifecycle from technology evaluation, development, integration, to flight equipment. Apart from space-grade hardware, TTTech Aerospace also provides customers with software tools for development and testing that offer a powerful development and production environment for building fault-tolerant real-time systems and enable seamless design, configuration, data loading, verification and validation of TTEthernet-based networks.
About TTTech Aerospace
TTTech Aerospace provides deterministic embedded network and platform solutions for aerospace and space applications. Its products have already completed over 1 billion flight hours in Level A safety-critical applications like fly-by-wire, power systems, avionics, engine controls and environmental control systems.
TTTech Aerospace is part of TTTech Computertechnik AG, a leading provider of safe networked computing platforms. TTTech is the innovator of Deterministic Ethernet and a driving force behind the IEEE TSN and the SAE AS6802 Time-Triggered Ethernet standards. TTTech Computertechnik AG operates under the umbrella of the TTTech Group, a globally oriented group of high-tech companies, founded and headquartered in Vienna, Austria.Internet Explorer Channel Network