Join the EPFL Spacecraft Team! 

Model Based Systems Engineering

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Type of project: Semester project / Association / Master thesis Participants: 2 - 4 students Section: STI, Minor in Space Tech or System Eng Description: In this project, you will join the CHESS mission at the end of Phase B, and you will contribute in bringing the mission to the next milestone, the PDR. To achieve this goal, you will need to focus on different tasks, mainly ICDs and Risk Analysis. The interface control documents (ICDs) are key to the CHESS mission. They define how the different components, subsystems of the satellite interact with each other to fulfill the mission’s objectives. The higher level architecture and requirements have been defined (mostly), we now need your help to dive into the specifics. The Risk Analysis identifies the possible failures of the system and it defines strategies to mitigate the causes and effects. Tasks:

• Familiarize yourself with the mission. As a system engineer it is your responsibility to be very well informed and be able to answer most questions or find the answers.

• Communicate with members from the other poles and universities to get information on the evolution of the subsystems development.
• Decompose the problem into manageable tasks.

• Make relevant design trade offs.

• Adapt to the situation.

• Be comfortable not knowing something and keep looking.

• Update the model of the satellite on Valispace (software) when necessary.

• Most importantly: be curious and enthusiastic about the work and the association! It will make it that much more fun.

Preferred background courses:

• Space Technologies minor

• Spacecraft Design and System Engineering

• Fundamentals of Systems Engineering

• Or similar knowledge, system engineering mentality

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Testing engineer

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Type of project: Semester project / Association Participants: 2 - 3 students Section: STI Description: We are starting to work on real satellite hardware. The Assembly Integration and Testing (AIT) phase is one of the most critical phases of any space project. It is not permitted to have issues with the system once the satellite is launched. A small error may result in a mission failure. The AIT allows to make sure that all the subsystems will work as expected in order to have a successful mission. We should have a first version of our On-Board-Computer, the Power system board and the ADCS module Tasks:

• Understand the roles and functions of the different subsystems which were bought.

• Create a list of test procedures which need to be performed on all newly bought subsystems.

• Test each subsystem individually according to this list.

• Work together with the Flight Software and OBC team.

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Power system engineer

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Type of project: Semester project / Association Participants: 4 students Section: STI Description: After extensive research and simulations on CHESS’s power generation and consumption, a COTS EPS has been selected and should be in our hands by February 2021. Being a vital element to the system, it is important to test the board, the batteries and the solar panel deployment system to make sure everything is well configured and ready to fly. You’ll be in touch with all of the other subsystems to try and simulate their power needs and test if the board and batteries distribute energy correctly and efficiently. Finally an estimation of State of Charge for the batteries should be made to ensure that the system lasts the full 2 years of the Mission. Tasks:

• Estimate State of Charge of Batteries for Battery monitoring

• Finalize and Confirm Power simulations

• Test the Power Distribution Board of the EPS

• Test the Batteries of on the EPS

• Discussions and work with the rest of the team to keep the system up to date

Preferred background courses:

• microcontrollers, electronic basis, coding skills (mainly for programming microcontrollers, C/C++)

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Hardware/Software in the loop testing

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Type of project: Semester project / Association Participants: 1 - 2 students Section: MT, Elec, others Description: The success of the mission depends on extensive testing of all components. Prior to hardware tests, in the loop testing is key. You’ll use two softwares developed by the ADCS supplier to test the ADCS algorithm and operational modes. You will also monitor the states of the ADCS and understand the functionality of the component. Finally you will be engaged in the developement of new ADCS modes tailored to the mission, including the definition of a safe flight mode and verify with simulations the operational capacity of the ADCS and of the newly defined modes. Tasks:

• Use EOS software to do Software and hardware in the loop testing.
• Use Cubesupport software to do hardware in the loop and monitor the ADCS states. Develop new operational modes for the ADCS.
• Manage data transmission between the ADCS computer (microcontroller) and the softwares.

Preferred background courses:

• C/C++ (EOS and Cubesupport softwares will be introduced to you)

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ADCS Test engineer

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Type of project: Association Participants: 1 students Section: STI, others Description: Upon the arrival of the complete ADCS module, we will need to test it. Your task will be to define a test protocol, establish the steps to follow, the key aspects to test, the potential failures. The tests will be held in collaborations with other subsystems so you will be ask to work with them. You will have to design the integration of the subsystems into one structure to be tested and the integration of that structure to the test bench (Helmholtz cage). Once the hardware is received you will have to apply this test protocol and report the results of the tests. Tasks:

• Develop a test protocol for the ADCS components, apply this protocol and report the results.

Background and skills :

• No particular skills, good understanding of mechanical and electrical systems is needed.

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ADCS integration with OBC and Flight software

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Type of project: Association Participants: 1 students Section: STI, Systeme de communication, others Description: In flight, the ADCS will be in constant connection and communication with other subsystems, mainly the On board Computer (OBC) and the Flight software. You will be asked to define the communication based on the existing commands. You will have to catalog all of the ADCS commands and communication protocols and ensure that the OBC and FS share the same protocol. You will also work with the test engineer to design the OBC-ADCS joint tests. Tasks:

• Establish communication protocol between ADCS and OBC/FS. Introduce the ADCS commands to the OBC, ensure the OBC controls the ADCS behavior.

Background and skills :

• Being able to work with other subsystems. Knowledge in communication protocols is recommended.

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Vibration Analysis

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Type of project: Association Participants: 1 students Section: STI Description: During the launch, the satellite withstands loads, vibrations that may use or break the structure. An analysis is carried out to derive the fundamental frequencies of the structure and detect eventual problems Tasks:

• The aim is to continue the project already done to apply ongoing modifications.

Preferred background and skills ::

• Ansys software

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Building of a mass model

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Type of project: Association Participants: 1 - 2 students Section: Any Description: To ensure the CubeSat sustains the launch and life in orbit, we have to verify the structure and the subsystems are capable of resisting a certain amount of vibrations and accelerations. In this context, we would like to build a realistic simplified model of the CubeSat and test this model in vibration. This position offers the opportunity to modify the design and build the mass model. Tasks:

• Machining/3D printing of a mass model

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Thermal Analysis/ Control

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Type of project: Semester project / Association Participants: 1 - 2 students Section: STI Description: The temperature of the satellite through its life is a crucial matter that has to be studied, to make sure every component stays in its operability range. An finite element analysis has to be carried out in order to check the thermal behavior and if the requirements are respected. Tasks:

• A first draft was done on Matlab, a FEM analysis must be done to obtain more precise results.

Preferred background and skills ::

• Matlab / Ansys

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Flight Software development

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Type of project: Semester project / Association Participants: 2 students Section: IC, Syscom, MT, Elec, others Description: The subject of this project concerns the development of the satellite's flight software (Flight Software - FSW) whose role is to manage all the interactions between the on-board computer (OBC) and the various subsystems (described above), as well as communication with the ground. An important point is the development of automatic procedures for testing the satellite to ensure that it functions correctly whatever the conditions. Currently several HES-SO students (Master's thesis, semester work) are designing and developing the on-board computer, the FSW, the test methodologies and a simulator to evaluate the functioning of the satellite with sub-systems that are not yet available. Tasks:

• The aim of the project is to take over the work done, improve it and make it fully functional with all the satellite's real subsystems. The notions of robustness and reliability are very important, test procedures according to the mission specifications must be set up and validated.
• Part of this work will be done with technologies developed by NASA such as FPrime (https://github.com/nasa/fprime).

Preferred background and skills:

• As this project involves a lot of people, the candidate will have to work in collaboration with engineers from other schools and other fields.
• C / C++ / Python

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Power system engineer

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Type of project: Semester project / Association Participants: 4 students Section: STI Description: After extensive research and simulations on CHESS’s power generation and consumption, a COTS EPS has been selected and should be in our hands by February 2021. Being a vital element to the system, it is important to test the board, the batteries and the solar panel deployment system to make sure everything is well configured and ready to fly. You’ll be in touch with all of the other subsystems to try and simulate their power needs and test if the board and batteries distribute energy correctly and efficiently. Finally an estimation of State of Charge for the batteries should be made to ensure that the system lasts the full 2 years of the Mission. Tasks:

• Estimate State of Charge of Batteries for Battery monitoring

• Finalize and Confirm Power simulations

• Test the Power Distribution Board of the EPS

• Test the Batteries of on the EPS

• Discussions and work with the rest of the team to keep the system up to date

Preferred background courses:

• microcontrollers, electronic basis, coding skills (mainly for programming microcontrollers, C/C++)

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Ground station emulation vhf/uhf communication

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Type of project: Semester project / Association Participants: 2 - 3 students Section: Elec, STI, others Description: Telecommand and telemetry data between the satellite and the ground station is provided via a vhf/uhf radiolink. An emulation of the ground station is required to test the satellite terminal. Within the scope of this work, the functions of a simple ground station are to be implemented on the basis of a commercially available SDR hardware. Tasks: Your task is to develop and implement the TC/TM modem functionality on the ground station side. In particular, the following focal points are to be worked on:

• Definition of the TC/TM protocol commands in consultation with the project partners concerned .

• Implementation and test of a suitable GUI application for the local generation of TC commands and the decoding of received TM commands.

• Implementation and test of the channel coding for the uplink and downlink radio channels according to project requirements. channel according to project requirements.

Preferred background and skills:

• Matlab, Gnu Radio advantageous

• Soft skills

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Baseband electronics for X-band communication terminal

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Type of project: Semester project / Association Participants: 1 students Section: Elec, STI, others Description: A radiolink in the 10 GHz range is provided for the transmission of scientific data. For the transmitter part on the satellite side, the baseband electronics will be designed and built as a prototype. Tasks: In particular, the following focal points need to be worked on:

• Familiarise yourself with the project

• Identify and describe function blocks for baseband signal processing.

• Evaluate commercially available components

• Prototype and characterise key functions (e.g. modulation)

Preferred background and skills:

• System simulation with AWR Design software advantageous

• Soft skills

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Power amplifier for x-band (10 GHz)

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Type of project: Semester project / Association Participants: 1 students Section: Elec, STI, others Description: The transmitting unit in the satellite requires a power amplifier for a frequency in the range of 10 GHz. The design should be based on components that are not subject to export restrictions by the USA. Within the scope of the semester project, an amplifier design is to be built and tested with the help of the supplier's specifications. Tasks: In particular, the following focal points need to be worked on:

• Familiarise yourself with the project

• Identify and describe the functional blocks for power amplification

• Evaluate commercially available components

• Prototype and characterise key functions (e.g. driver, pa)

Preferred background and skills:

• System simulation with AWR Design software advantageous

• Soft skills

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Concept of Operations development

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Type of project: Semester project / Association Participants: 2 - 4 students Section: STI, Minor in Space Tech Description: The Concept of Operations (CONOPS) is what defines how the satellite will work after the launch at the system level. This is a crucial part of the mission as it states what will be the time sequence of the operations and what to do in case of a failure. The CONOPS has been started the last semesters but it has to be precisely refined in order to be fully operational for the mission. Tasks:

• Finalizing the CONOPS

• Implement it in Valispace (MBSE tool)

• Duty cycles analysis

• Power, Data, Mass budgets determination

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Vibration Analysis

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Type of project: Association Participants: 1 students Section: STI Description: During the launch, the satellite withstands loads, vibrations that may use or break the structure. An analysis is carried out to derive the fundamental frequencies of the structure and detect eventual problems Tasks:

• The aim is to continue the project already done to apply ongoing modifications.

Preferred background and skills ::

• Ansys software

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Building of a mass model

---

Type of project: Association Participants: 1 - 2 students Section: Any Description: To ensure the CubeSat sustains the launch and life in orbit, we have to verify the structure and the subsystems are capable of resisting a certain amount of vibrations and accelerations. In this context, we would like to build a realistic simplified model of the CubeSat and test this model in vibration. This position offers the opportunity to modify the design and build the mass model. Tasks:

• Machining/3D printing of a mass model

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Thermal Analysis/ Control

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Type of project: Semester project / Association Participants: 1 - 2 students Section: STI Description: The temperature of the satellite through its life is a crucial matter that has to be studied, to make sure every component stays in its operability range. An finite element analysis has to be carried out in order to check the thermal behavior and if the requirements are respected. Tasks:

• A first draft was done on Matlab, a FEM analysis must be done to obtain more precise results.

Preferred background and skills ::

• Matlab / Ansys

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Power system engineer

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Type of project: Semester project / Association Participants: 4 students Section: STI Description: After extensive research and simulations on CHESS’s power generation and consumption, a COTS EPS has been selected and should be in our hands by February 2021. Being a vital element to the system, it is important to test the board, the batteries and the solar panel deployment system to make sure everything is well configured and ready to fly. You’ll be in touch with all of the other subsystems to try and simulate their power needs and test if the board and batteries distribute energy correctly and efficiently. Finally an estimation of State of Charge for the batteries should be made to ensure that the system lasts the full 2 years of the Mission. Tasks:

• Estimate State of Charge of Batteries for Battery monitoring

• Finalize and Confirm Power simulations

• Test the Power Distribution Board of the EPS

• Test the Batteries of on the EPS

• Discussions and work with the rest of the team to keep the system up to date

Preferred background courses:

• microcontrollers, electronic basis, coding skills (mainly for programming microcontrollers, C/C++)

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