Scientific description :
The LISA space mission aiming at measuring gravitational waves in the mHz regime will be launched in 2035. The principle of this mission is to measure the optical path length variation between free falling test masses located in 3 spacecraft in heliocentric orbits.

During the mission, the 3 spacecraft will be tracked by radioscience measurements performed by tracking stations on Earth. These measurements will allow ESA to reconstruct the orbit of the spacecraft. In addition, the information about the on-board clocks will be encoded in the signal sent from the S/C to the tracking station. When compared to the local clock of the tracking station, this allows to synchronize the on-board clocks with respect to terrestrial time (these measurements are usually referred to as "time couples").

This internship aims at simulating the orbit reconstruction of the 3 LISA spacecraft as well as the corresponding time couples and to include such simulations in the global simulation software used by the LISA consortium. We will also study the impact of various observations schemes on the orbit reconstruction and, if time allows, we will also explore how such uncertainties propagate in the LISA data analysis.

Practically, in this internship, we will be using the GODOT software, a python package developed by ESA to develop future space missions. This internship will take place at SYRTE and is suitable for a well-motivated student with good programming skills (especially in python) and good knowledge of orbital mechanics.

Applicant skills :
The internship is dedicated to a Master (M1 or M2) student or a student from an engineer school. The applicant should have good programming skills (Python) and ideally, good knowledge of orbital mechanics.

Duration :2-4 months

Contact : Aurélien Hees, aurelien.hees AT obspm.fr

Collaboration : this internship will be performed in close collaboration with scientists from ESOC – ESA (Germany).

Starting date : any time from February 2024.