State-of-the-art onboard spacecraft avionics use SpaceWire networks to interconnect payload data-handling sub-systems. This includes high data-rate sensors and instruments, processing units, and memory devices. SpaceWire is an interconnection network composed of nodes and routers connected by bi-directional, point-to-point, high-speed, serial-data communication links. SpaceWire is established as one of the main data-handling protocols and is being used on many ESA, NASA and JAXA spacecraft. SpaceWire is very successful for being fast, flexible and simple to use and implement. However it does not implement Quality of Service mechanisms, which aim to provide guarantees in terms of reliability and timely delivery to data generated by network clients. Quality of Service is increasingly being deployed in commercial ground technologies and its availability for space applications, which requires high reliability and performance, is of high interest for the space community. This thesis researches how Quality of Service can be provided to existing SpaceWire networks. Existing solutions for ground-based technologies cannot be directly used because of the constraints imposed by the limitations of space-qualified electronics. Due to these limitations SpaceWire uses wormhole routing which has many benefits but makes it more challenging to obtain timing guarantees and to achieve a deterministic behaviour. These challenges are addressed in this work with a careful analysis of existing Quality of Service techniques and the implementation of a novel set of protocols specifically designed for SpaceWire networks. These new protocols target specific use cases and utilise different mechanisms to achieve the required reliability, timely delivery and determinism. Traditional and novel techniques are deployed for first time in SpaceWire networks. In particular, segmentation, acknowledgements, retry, time-division multiplexing an cross-layer techniques are considered, analysed, implemented and evaluated with extensive prototyping efforts. SpaceWire provides high-rate data transfers but the next generation of payload instruments are going to require multi-gigabit capabilities. SpaceFibre is a new onboard networking technology under development which aims to satisfy these new requirements, keeping compatibility with SpaceWire user-applications. As a new standard, SpaceFibre offers the opportunity to implement Quality of Service techniques without the limitations imposed by the SpaceWire standard. The last part of this thesis focuses on the specification of the SpaceFibre standard in order to provide the Quality of Service required by next generation of space applications. This work includes analytical studies, software simulations, and hardware prototyping of new concepts which are the basis of the Quality of Service mechanisms defined in the new SpaceFibre standard. Therefore, a critical contribution is made to the definition and evaluation of a novel Quality of Service solution which provides high reliability, bandwidth reservation, priority and deterministic delivery to SpaceFibre links.

There is a need for increasing speed on external links and harmonics are often seen and are a challenge to master. Especially for products within the space industry where the requirements are narrower due to the harsh environment it needs to withstand. This thesis is investigating a potential leakage path around the interface from the board to harness through Spacewire connectors. This leakage is seen as radiated emission and the focus of this thesis is to see if there is a possibility to decrease these emissions by minimising the ground loop that is potentially causing these issues in the UHF- and S-band. In order to verify that the proposed solution a reverberation chamber was used to analyse the performance of the solution when a twisted cord attached to a ground plane and wrapped around the harness was used to minimise the dierence in potential between the interface of the board to harness. The results showed that the proposed solution was inconclusive, but another discovery was made, it was found that the radiated emissions seen in the S-band can be decreased signicantly by improving the contact between the connector and the frame. This could be done with a beryllium-copper gasket. A decrease could also be seen in the UHF-band but not as substantial as the S-band.

SpaceWire est un standard de réseau embarqué promu par l'Agence Spatiale Européenne qui envisage de l'utiliser comme réseau bord unique dans ses futures satellites. SpaceWire utilise un mécanisme de routage Wormhole pour réduire la consommation mémoire des routeurs et les coûts associés. Cependant,le routage Wormhole peut engendrer des blocages en cascade dans les routeurs et, par conséquent,d'importantes variations des délais de livraison des paquets.Comme le réseau doit être partagé par des flux critiques et non-critiques, les concepteurs réseau ont besoin d'un outil leur permettant de vérifier le respect des contraintes temporelles des messages critiques. Pour réaliser cet outil, nous avons choisi comme métrique une borne supérieure sur le délai pire-cas de bout en bout d'un paquet traversant un réseau SpaceWire. Au cours de la thèse, nous avons proposé trois méthodes permettant de calculer cette borne. Les trois méthodes utilisent des hypothèses différentes et ont chacune des avantages et des inconvénients. D'une part, les deux premières méthodes sont très générales et ne nécessitent pas d'hypothèses restrictives sur le trafic en entrée du réseau. D'autre part, la troisième méthode nécessite des hypothèses plus précises sur le trafic en entrée. Elle est donc moins générale mais donne la plupart du temps des bornes plus serrées que les deux autres méthodes. Dans cette thèse, nous avons appliqué ces différentes méthodes à une architecture de référence fournie par Thales Alenia Space afin d'en comparer les résultats. Nous avons également appliqué ces méthodes à des exemples plus simples afin de déterminer l'influence de différents paramètres sur les bornes fournies par nos méthodes. / The SpaceWire network standard is promoted by the ESA and is scheduled to be used as the sole onboard network for future satellites. SpaceWire uses a wormhole routing mechanism to reduce memoryconsumption and the associated costs. However, wormhole routing can lead to packet blocking in routerswhich creates large variations in end-to-end delays. As the network will be shared by real-time and nonreal-time traffic, network designers require a tool to check that temporal constraints are verified for allthe critical messages. The metric we chose for this tool is an upper-bound on the worst-case end-to-enddelay of a packet traversing a SpaceWire network. This metric is simpler to compute than the exact delayof each packet and provide enough guarantee to the network designers. During the thesis, we designed three methods to compute this upper-bound. The three methods use different assumptions and have different advantages and drawbacks. On the one hand, the first two methods are very general and do not require strong assumptions on the input traffic. On the other hand, the third method requires more specific assumptions on the input traffic. Thus, it is less general but usually gives tighter bounds than the two other methods. In the thesis, we apply those methods to a case study provided by Thales Alenia Space and compare the results. We also compare the three methods on several smaller networks to study the impact of various parameters on their results.

The thesis deals with design and implementation of controllers for the RMAP protocol, which is used by SpaceWire network endpoints to access memory contents of another endpoint. The theoretical research introduces concepts of the SpaceWire network, then describes the RMAP protocol and the AMBA AHB bus interface in detail. The practical part of this thesis then uses this information to design and implement controllers for the RMAP protocol. It first defines an architecture of these controllers, then describes design of individual blocks based on this architecture. As a next step, the thesis describes methods used to verify designed controllers and to test these controllers in an FPGA chip. Finally, an analysis of maximum frequency and usage of FPGA resources is done based on estimates provided by the synthesis tool.

Future spacecrafts will require more computational and processing power to keep up with the growing demand in requirements and complexity. ScOSA is the next generation on-board computer developed by the German Aerospace Centre (DLR). The main motivation behind ScOSA is to replace the conventional on-board computer with distributed and reconfigurable computing nodes which provides higher performance, reliability, availability and stability by using a combination of the COTS components and reliable computing processors that are space qualified. In the current ScOSA system reconfiguration and routing of data between nodes are based on a static decision graph. SpaceWire protocol is used to communicate between nodes to provide reliability. The focus of the thesis is to design and implement a dynamic routing protocol for ScOSA which can be used in future for not only communicating between the nodes but also for reconfiguration. SpaceWire IPC is a customized protocol developed by DLR to provide communication between the nodes in a distributed network and to support monitoring, management and reconfiguration services. The dynamic routing protocol proposed in this thesis is primarily derived from the monitoring mechanism used in the SpaceWire IPC. PULL type monitoring mechanism is modelled and simulated using OMNeT++. The results obtained provide a qualitative outlook of the dynamic routing protocol implemented.

This work presents the advancements in the development of simulation models of spacecraft components as part of a testbench for verification of onboard flight software. The satellite and its mission are briefly described as to give an idea of the conditions where the simulation has to run. The simulation environment, SimTG, is also introduced and a description of the developed models is presented. The models required interaction between different simulation environments, real hardware and simulated hardware, and also some data processing was necessary in order to filter undesired information. Finally, the performance of the models was tested and verified and a sensible improvement of the state of the testbench on the simulation side was achieved, although a considerable amount of work still lies ahead before a complete onboard software verification tool is ready.

This thesis describes the design of a board-level testing platform for monitoring and driving a selected set of interfaces used in space applications. The requirements of these devices are based on the corresponding ECSS, IEEE, and TIA standards described in the theoretical part of this thesis. The designed testing device is controlled by the Xilinx Zynq-7000 system-on-chip and is connected to a control PC via an Ethernet connection. The hardware, designed on a schematic level is responsible for meeting the standards' requirements. The software part consists of a Python module for the control PC providing a set of functions to be used in the testing process and a C application for the embedded ARM processor that forwards the data through the AXI interface to the interface drivers in the programmable logic.

<p>This report is a result of a thesis work done for Linköping University at Contraves Space AG in Zürich, Switzerland. The aim was to perform an analysis of 12 interface standards and construct a simple breadboard, which should function as a testsystem for the data communication interface MIL-STD-1553. </p><p>The conclusion of the extensive analysis is that SpaceWire, MIL-STD-1553 and CAN are the most interesting interfaces for future data communication in spacecrafts. In the breadboard part of the work, a test system was built and data gathered with help from a demonstration program that came with one of the components.</p>

This report is a result of a thesis work done for Linköping University at Contraves Space AG in Zürich, Switzerland. The aim was to perform an analysis of 12 interface standards and construct a simple breadboard, which should function as a testsystem for the data communication interface MIL-STD-1553. The conclusion of the extensive analysis is that SpaceWire, MIL-STD-1553 and CAN are the most interesting interfaces for future data communication in spacecrafts. In the breadboard part of the work, a test system was built and data gathered with help from a demonstration program that came with one of the components.