OHB Sweden is a leading Swedish supplier of space systems. We develop, build, test and commission satellites and subsystems for space missions in, for example, communication, earth observation and space research for institutional and commercial customers within and outside Europe.

Many AOCS projects depend on accurate models of flexible appendages and the dynamics of propellant sloshing in tanks. Several challenges exist to be able to establish good reliable models of these kinds of dynamics that can be efficiently used in the frame of spacecraft AOCS design, development, and performance verification.

Models exist for flexible and sloshing dynamics that are possible to use for the tuning and simulation of spacecraft attitude and orbit control systems (AOCS). However, there are many challenges associated with the implementation of these models in order to guarantee that they can be efficiently and reliably used in the development the AOCS.

The tasks of the master's thesis topic are as follows:

• Representing the transition between non-accelerated and accelerated state for propellant tanks
• Modelling of propellant settling
• Making sure that all fictitious torques and forces are correctly taken into account
• Making sure that the dynamic systems have uncertainty parameterizations which guarantee that the resulting systems are physically correct
• The establishment of separate models for analysis and simulation with common parameter definitions and sources
• Establishment of a simplified approach to determine parameter values for preliminary simulations
• The work also includes the definition of associated validation test cases to allow the verification of correct operation of the developed tools.
• Review of existing models and tools within the company
• Literature study covering
• Modeling techniques for flexible appendages and propellant sloshing
• Uncertainty modeling techniques
• Accelerated state transitions
• Propellant settling
• Study and implementation of the different aspects to be covered including
• Derivation of low-order, simulation-tailored models
• Eventual development of Computational fluid dynamics (CFD) models adapted to tank sloshing in satellites
• Development and execution of validation cases
• Documentation

The purpose of the Master Thesis work is to investigate the different aspects listed above and to adapt and develop existing tools to address these aspects.

The required candidate’s skills are:

• Specialization in applied mathematics and automatic control
• Knowledge in analytical mechanics
• Strong analytical, problem-solving, and innovative thinking skills.
• Familiarity with Matlab and Simulink analysis tools
• Eventual familiarity with CFD simulation tools.
• Self-motivation and the ability to work both independently and in teams with attention to detail.
• Excellent communication and presentation skills for sharing findings with both technical and non-technical stakeholders

This is a unique opportunity to contribute to the advancement of satellite modelling while gaining valuable experience in the space industry. During the Master Thesis, OHB Sweden is offering support and technical expertise from highly skilled, motivated and innovative AOCS engineers.

The Master thesis requires you to be in Stockholm at our office in Kista and cannot be done remotely. We follow the export controls law and this regulates which country of birth people who work on our projects may have. We at OHB cannot influence this law.

We look forward to your application! 😀