The CanX-4 and CanX-5 mission currently under development at The University of Toronto Institute for Aerospace Studies Space Flight Laboratory UTIAS/SFL is a challenging formation flying technology demonstration. Its requirements of sub-metre control accuracy have yet to be realized with nanosatellites. Many large technical challenges must be addressed in order to ensure the success of the CanX-4/5 mission. This includes the development of software for an intersatellite communication system, integration and optimization of key formation flying algorithms onto the Payload On-Board Computer as well as the development of a Hardware-In-The-Loop simulator for full on-orbit mission simulations. This thesis will provide background knowledge of the Space Flight Laboratory and its activities, the CanX-4/5 mission, and nally highlight the authors contributions to overcoming each of these technical challenges and ensuring the success of the CanX-4 and CanX-5 mission.

The CanX-4 and CanX-5 mission currently under development at The University of Toronto Institute for Aerospace Studies Space Flight Laboratory UTIAS/SFL is a challenging formation flying technology demonstration. Its requirements of sub-metre control accuracy have yet to be realized with nanosatellites. Many large technical challenges must be addressed in order to ensure the success of the CanX-4/5 mission. This includes the development of software for an intersatellite communication system, integration and optimization of key formation flying algorithms onto the Payload On-Board Computer as well as the development of a Hardware-In-The-Loop simulator for full on-orbit mission simulations. This thesis will provide background knowledge of the Space Flight Laboratory and its activities, the CanX-4/5 mission, and nally highlight the authors contributions to overcoming each of these technical challenges and ensuring the success of the CanX-4 and CanX-5 mission.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Satellites are not all made equal. The large number of possible orbits, desired functionality and budget constraints are but a few of the factors that influence the design of a satellite. Given a particular set of design requirements, a number of designs may meet these requirements. Each of these designs will typically entail a trade-off between a number of (conflicting) parameters, whilst still satisfying the system requirements. The On-Board Computer (OBC) of a satellite, the satellite subsystem primarily responsible for the operational control of a satellite, can consequently be designed in any of a number of different ways. As the factors that influence the flight performance of an OBC differs to those of a terrestrial computer, the OBC design will therefore be significantly different. A high-level overview of the factors that impact OBC design and operation is presented. Improvements to the existing designs are proposed. In conclusion, a number of guidelines for a future OBC design also are given. / AFRIKAANSE OPSOMMING: Elke satelliet het unieke eienskappe wat bepaal word deur onderandere, die teiken wentelbaan, verwagte funksionaliteit en koste oorweegings. Vir 'n spesefieke stelselontwerp bestaan daar 'n aantal moontlike ontwerpe wat aan die stelsel vereistes voldoen. Elk van hierdie ontwerpe sal tipies behels dat verskillende parameters teen mekaar afgespeel word, terwyl die stelsel vereistes steeds aan voldoen word. Die Aanboord Rekenaar (AR) van 'n satelliet, die satelliet substelsel hoofsaaklik verantwoordelik vir die beheer van die satelliet, kan vervolgens uit een van veele moontlike ontwerpe bestaan. Aangesien die faktore wat die werkverrigting van 'n AR beinvloed verskil van die van 'n rekenaar wat op die aard oppervlak gebruik word, sal die AR ontwerp dienooreenkomstig verskil. 'n Hoevlak oorsig van die faktore wat AR ontwerp beinvloed sal gegee word. Verbeteringe wat aan die huidige AR ontwerpe gedoen kan word sal bespreek word. Ter afsluiting sal 'n aantal riglyne vir toekomstige AR ontwerpe gegee word.

Internet of Things is rapidly evolving. This thesis includes a study of single-board computers suitable for machine-to-machine communication together with the developing process of a sensor network integrated with a bidirectional communication platform. Raspberry Pi was selected as the single-board computer used in the proposed system. The Message Queuing Telemetry Transport protocol was selected as main communication protocol to handle all exchange of information between the network and the bidirectional communication platform. It was selected because of its reliability, low bandwidth and publish/subscribe architecture. Decision-making procedures were implemented to work with both local sensor data and data from different Message Queuing Telemetry Transport streams, such as GPS data, used to calculate the distance between the user’s smart phone and the office to prepare the workstation, temperature sensors and ambient light sensors controlling Philips HUE light bulbs. The finished sensor network was design to work within office environments to prepare workstations and monitor the work climate. The number of sensors connected to the single-board computer has a major impact in the CPU usage. Measurements and calculations show that 17 connected physical sensors will cause a CPU usage of 96%.

The thesis elaborates on an implementation of wireless home security system. The wireless communication utilizes IEEE 802.15.4 radios and ZigBee communication protocol. The beginning of the thesis provides specification of the intended system followed by an evaluation of usable energy harvesting solutions and later by consideration of single board computer systems suitable for implementation of the control node of the sensor network. The rest of the thesis describes design, implementation and testing of particular components of the security system. Conclusion evaluates the achieved goals and offers suggestions for future work. The end products of the thesis are physical devices implementing wireless sensor nodes, control unit of the security system as well as a graphical user interface for the system management.