Falling rate of space objects

In Low Earth Orbit (LEO), the satellites suffer from an increasing drag as soon as their altitude decrease. The satellites orbiting the Earth in the altitude lower than 600km are subject to a residual atmospheric drag. This effect has an important impact on the evolution and prediction of the orbital parameters, essential for space situational awareness (SSA). The atmospheric drag depends heavily on the geometry of the spacecraft, the altitude and the solar activity, among others. The goal of this project is to better characterize the multiple influences on space objects, and predict the global impact on the orbit cause by the related drag.

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Objectives

  • Litterature review: Conduct an in-depth research in the litterature to understand how the orbit propagation is performed with different tools. It will be also necessary to understand drag in LEO
  • Study and modeling: evaluate the ballistic coefficient (BC) of the LEO objects, study the impact on solar activity on the drag, and study the evolution of the effective BC with respect to the orientation of the spacecraft.
  • Prediction: design a tool to compute the lifetime (desorbiting) of a spacecraft based on its physical characteristics, systems and orbital parameters.
  • Analysis: find a theoretical threshold to differentiate between natural decay and active maneuvers.

Required skills

Space orbital dynamics: understanding the fondamental of orbital mechanics and space engineering principles.

Coding language: being able to program in Java or python, implement tests and documentations.

Orekit: knowledge in the Python Orekit library is a plus.

These skills will enable students to actively contribute to the project and make meaningful advancements in the understanding of satellites’ maneuvers.

Place of work

The student will have the opportunity to work in a stimulating environment with other students in different locations (Lausanne, Bern, Zurich) in Switzerland depending on the needs of the projects.

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Deliverables

  • Reporting: a detailed report outlining the analysis of the problem, the solution provided and the suggestion of propulsion systems
  • Source code: the software with examples of execution.
  • Recommandations: in addition of the main documentations, recommendations for further work and improvement to the final product