Student theses

The next generation of human space exploration missions will take crews farther away from Earth than ever before. These missions will necessitate increasingly sophisticated Life Support Systems (LSSs) to ensure astronauts stay alive, healthy and happy. Mission scenarios of this kind therefore require greater autonomy, relying on simulations as well as laboratory setups to recreate the nominal behaviour of the LSS during all mission phases.
In order to be able to simulate these complex LSSs at the Institute of Space Systems (IRS), a small-scale laboratory model of a LSS is being constructed. Since such a complex undertaking requires detailed planning, a Model Based Systems Engineering (MBSE) approach is suggested to optimize the development process. This approach can also be combined with a Digital Twin of the laboratory model that is currently being implemented at the IRS.
This thesis explores MBSE for developing a Life Support System from the ground up. It covers foundational knowledge of MBSE and Requirements Engineering, reviews relevant tools and system architecture, examines integrating MBSE with the Digital Twin, and evaluates the resulting approach.

The next generation of human space exploration missions will require increasingly sophisticated life support systems (LSS) to sustain crews on long-duration missions far from Earth. V HAB, a powerful simulation system for modeling complex LSS, employs a unique bottom-up approach that allows for high-precision modeling of all LSS components up to a user-defined granularity. This approach enables V HAB to maintain high modeling accuracy by providing detailed information on mass flow, temperature, pressure, humidity, and composition for each individual process and subsystem.
Currently, V HAB operates entirely within MATLAB without requiring additional packages or toolboxes. It offers a library of pre-defined basic LSS components, allowing users to integrate existing subsystems into their designs rather than starting from scratch. However, V HAB lacks a user-friendly graphical interface. (GUI), hindering its accessibility and usability, especially for new users. This master's thesis will work in parallel with the ongoing development of the V HAB GUI to compare the suitability of Synera as an alternative approach.
Synera, a modern low-code automation platform, offers the potential to address these gaps and enhance V HAB's capabilities. The integration of V HAB with Synera provides significant potential to improve the functionality and user experience of the LSS modeling platform. By leveraging Synera's capabilities, the integrated system could provide a user-friendly graphical interface, streamline the design process with quick options and arranging tools, and offer real-time feedback through automated logic tests and live updating feeds. These features would make V HAB more accessible to new users while providing comprehensive overviews of designed LSS and enhancing understanding of their operations.
This master's thesis aims to investigate and implement this integration, creating an advanced modeling platform that enables more efficient data generation, improved visualization of simulation results, and enhanced automation of modeling workflows.

The LunarCobot project is investigating the deployment of heterogeneous robot teams on the lunar surface. Multi-robot operations and autonomous system networks enable complex mission profiles to be carried out through the use of multiple specialised robotic systems, which is particularly relevant for exploring challenging environments on the lunar surface. A key research focus of the project is on increasing the technology readiness level of various robotic technologies and modular exploration systems through further development of hardware and software, as well as the evaluation of these technologies in an analogue environment.

The aim of this thesis is to further develop the contactless interface in the tether mechanism of the Nanokhod microrover. The rover is connected to a primary system via a 100 m long tether and uses an inductive coupler within the coil body to avoid the use of slip rings, which are prone to wear. The aim of the work is to adapt the converter and transformer circuit of the Wireless Power Transfer (WPT) module for integration into a rotating measurement setup that reproduces the geometric and dynamic boundary conditions of the coil winding. Subsequently, the simultaneous power and data transmission must be experimentally investigated and quantified. In the measurement setup, the effects of rotation, air gap and other interfering parameters are to be systematically identified, evaluated and documented in the form of measurement data.

Tasks:
• Further development of the transmission link from the primary system to the rover
• Design of a suitable measurement setup and implementation in a laboratory environment
• Adaptation and integration of the converter assembly into the measurement setup
• Characterisation of the measurement link during test operations

Real-time functional satellite simulators play a fundamental role in the development, testing and operation phases of a satellite’s lifetime. In particular at the Institute of Space Systems (IRS), simulators have been previously used for various tasks such as flight software and controller verification as well as operation training. As part of the small satellite mission ROMEO (Research and Observation in Medium Earth Orbit), the functional simulator is further developed to become ROMEO’s Digital Twin (DT) on the ground. By definition, a DT is created when there is bidirectional data exchange between the simulated system and its real counterpart that also interacts with the real satellite. By identifying the desired simulation parameters that can define the real-world behavior of satellite systems and calibrating these parameters using known system information and recorded satellite telemetry, it is possible to simulate a more accurate and realistic system state in real-time, and into any past or future time.

This Master's thesis explores the feasibility of a satellite's status prediction using the existing simulation tools and data at IRS. In particular, data-driven methods of parameter calibration and optimization in simulation and modelling are investigated. Furthermore, the feasibility of the Rust programming language and the NeXosim simulation framework in AI realm is questioned. Consequently, the collected knowledge is used to adjust the EPS model of the satellite to incorporate recorded telemetry data from a previous mission and to test whether the selected approach can effectively predict the status of the EPS into the future.

The LunarCobot project is investigating the deployment of heterogeneous robot teams on the lunar surface. Multi-robot operations and autonomous system networks enable complex mission profiles to be carried out through the use of multiple specialised robotic systems, which is particularly relevant for exploring challenging environments on the lunar surface. A key research focus of the project is on increasing the technology readiness level of various robotic technologies and modular exploration systems through further development of hardware and software, as well as the evaluation of these technologies in an analogue environment.

The aim of this work is to further develop the transceiver circuits of the Nanokhod microrover, which perform key functions relating to the rover’s communication and power supply. In order to prepare the existing laboratory setup of the transmission link for subsequent integration into the overall system, new PCB designs for the transceiver circuits must be developed and power-optimised components selected. Furthermore, the development is to be experimentally validated through precise measurements and integrated into the existing laboratory setup. In preparation for the integration of the rover into compact payload modules, the constraints of the analogue mission are to be taken into account, and innovative concepts for implementing the required transceiver electronics are to be developed and evaluated.

Tasks:
• Further development of the central interface for simultaneous data communication and power supply to the rover
• Design of a customised transceiver circuit to enable the transfer of laboratory set-ups into payload modules
• Detailed development and implementation of the new PCB design
• Measurement and characterisation of the developed electronics and test setup

Functional satellite system simulators play a fundamental role in the development, testing and operation phases of a satellite’s lifetime. Simulators consist of deterministic software models of the satellite hardware as well as models simulating the space environment, such as the gravitational and magnetic fields, temperature fluctuations, etc. and the consequent perturbations on the satellite dynamics. Hence, simulators are widely used in hardware-in-the-loop setups, flight software and controller verification as well as operation training. Operation training involves the training of satellite operations’ staff, during which the team is exposed to realistic mission scenarios and contingency situations by means of the simulated satellite telemetry to practice procedures.

As part of the small satellite mission ROMEO (Research and Observation in Medium Earth Orbit), a satellite system simulator has been built using the NeXosim simulation framework. The framework is developed in Rust programming language and provides a component-oriented architecture to define time-driven state machines which model the functional behavior of the systems, as well as a runtime environment for the execution of simulations.

In the frame of this Master’s thesis the NeXosim application programming interface (API) shall be implemented to allow initiation of simulations, and runtime monitoring and control of the simulation models. The NeXosim API shall be further extended to meet the defined requirements for the operation training and the interface between the simulator and the operation system SatOS. This includes an investigation and adaptation of the API’s capability to inject instructions and system failures from SatOS into the simulations, which are necessary for the simulation of contingency situations.

When communicating with satellites in orbit, the antennas used on ground are mostly
large parabolic dish antennas. Those antennas, depending on their size, need to be
oriented towards the satellite with an accuracy of below 1°. To achieve such accuracies,
the antenna orientation on ground needs to be calibrated.
A common way to do this, is to receive signal from satellites with a known orbit and to
determine the offset between the known orbit and the antenna orientation. A big
disadvantage is, that the antennas can only be calibrated in the directions of known
satellites, that transmit over the antenna location in the same frequency band. And in
addition, the calibration can only be done, when those satellites pass over the ground
station.
To mitigate this disadvantage, a new way for calibration shall be developed. For this
purpose, star images shall be used. Using images of the night sky, the orientation of the
camera used for taken the image can be determined with arc second accuracy using
already existing algorithms. Using this this technique, a method and software for a full
antenna calibration shall be developed within this thesis.

Task description of the Master thesis work:
- Research of all necessary components
- Develop Calibration Method
- Implementation of the Method
- Verification of the Method
- Documentation

Motivation:
The growing use of small satellite constellations in Low Earth Orbit (LEO) for purposes such as earth observation, communication and other commercial services presents significant potential for business opportunities and technological advancements. However, it is also accompanied by challenges, such as the need for de-orbiting and disposal of satellites at their end-of-life with a low-risk probability of causing property damage or casualties on the ground. This is ensured during the development of the satellites using numerical tools such as ESA’s SCARAB software, which analyzes demisability. Additionally, plasma wind tunnel (PWT) experiments provide a valuable opportunity to study the demise behavior of materials and structures in plasma environments relevant to re entry. Past studies have revealed that glass fiber reinforced polymers (GFRPs) as used in printed circuit boards (PCBs) are resistant to high temperatures and demise worse than expected. In order to improve the understanding of demise processes and calibrate numerical models, experimental PWT studies are performed within the SKALE project. One critical parameter for the description of demise processes is temperature and its spatial distribution on test objects. Therefore, the specimens are to be equipped with thermocouples. The surface temperature can be measured using pyrometers and thermal imaging cameras. The resulting measurement data can then be compared to the numerical simulation results for validation and verification purposes.
Task Description:
• Introduction to uncontrolled re-entry, PWT testing, and the SCARAB simulation software
• Set-up of a test plan for the demise of PCB samples
• Preparing and assisting PWT experiments
• Numerical rebuilding of PWT experiments in SCARAB
• Analysis of measurement data and comparison to simulation results
• Documentation