Understanding the stability, transformation, and detectability of organic molecules in space environments is central to astrochemistry and exobiology. Molecules such as hydrocarbons, amino acids, lipids, pigments, and larger assemblies of organic molecules act as tracers of chemical complexity and potential biosignatures. Their behavior under solar UV radiation, cosmic rays, altered gravity, and vacuum or other planetary conditions directly affects our ability to interpret astronomical observations and exploration data, assess planetary habitability, and design life-detection strategies. Laboratory simulations provide valuable insights, but only direct space exposure reveals the combined effects of these factors.

This PhD project will investigate the photochemistry of organic molecules in space, focusing on their stability, degradation, and biosignature preservation. Research will combine two complementary approaches: in-situ exposure experiments aboard the International Space Station using ESA’s OREOcube and Exocube platforms (PI: Andreas Elsaesser) of the EXOBIO program (launch early 2027), and high-fidelity ground simulations in planetary environment chambers.

OREOcube studies organic molecules and minerals in thin-film configurations with autonomous UV-Vis-NIR and FTIR spectroscopy, providing continuous in-orbit monitoring on the ISS Bartolomeo platform. Exocube extends these capabilities to biochemical systems, using microfluidics and fluorescence/infrared spectroscopy to monitor biomolecular stability and activity in real time. Both payloads also allow sample return for detailed post-flight analyses using advanced laboratory techniques.

The candidate will prepare, monitor, and analyze samples flown on OREOcube and Exocube, including aliphatic and polycyclic aromatic hydrocarbons, porphyrins, lipids, pigments, and simple biomolecules relevant to prebiotic chemistry. Their photochemical stability will be investigated in thin films and in matrices such as minerals, salts, and ices to evaluate protective or catalytic effects. ISS experiments will provide real-time data on molecular transformations under the combined influence of UV radiation, cosmic rays, microgravity, and vacuum.

In parallel, laboratory simulations will recreate planetary and astrophysical conditions. Facilities include a Mars chamber (low-pressure CO₂, perchlorates, UV), a cryogenic setup for icy moons and interstellar ices (down to 10 K, deep-UV and electron irradiation), and an atmospheric chamber for Titan and exoplanetary conditions. Using FTIR, UV-Vis, Raman, and VUV spectroscopy complemented by mass spectrometry, the candidate will track photoproduct formation, reaction kinetics, and the role of environmental matrices in molecular stabilization or degradation.

The PhD will be hosted at the Institut UTINAM (UMR 6213 CNRS – Université Marie et Louis Pasteur, Besançon), which provides the laboratory infrastructure, supervision, and scientific network essential for this research. The project timeline follows the EXOBIO mission phases. From mid-2026 to early 2027, the student will focus on sample preparation for the spaceflight experiment, setup of laboratory studies, and establishment of the ground reference experiment (GREM) using flight-analog hardware. During 2027, they will conduct GREM and laboratory work, synchronizing ground-based data with in-situ spectroscopic results from the ISS. From 2028 onward, they will analyze post-flight samples with high-resolution spectroscopy and microscopy, continue laboratory experiments, and publish results with ESA and CNES partners. The final year (2029) will focus on data synthesis, publications, thesis writing, and presentations at international conferences.

Combining space- and ground-based experiments is the strength of this project. Space exposure provides authenticity, while laboratory work enables systematic testing and mechanism exploration. Together, they will deliver an unprecedented dataset on organic photochemistry and biomarker stability.

The results will advance astrochemistry (molecular evolution in interstellar and planetary environments), life-detection strategies (identifying stable biomarkers and their spectral signatures), and space exploration (radiation effects on biomolecules and materials). The project directly supports ESA and CNES missions targeting Mars, icy moons, exoplanets, and future lunar and deep-space platforms such as SpectroCube and METIS.

The PhD will offer comprehensive training at the interface of exobiology, astrochemistry, spectroscopy, and space instrumentation. The candidate will acquire skills in sample preparation, contamination control, spectroscopy, and mission operations, and work closely with ESA, CNES, and European partners. Hosted at UTINAM and UMLP, this project will train the next generation of scientists for space research in France and foster integration into the international exobiology and astrochemistry community.

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For more Information about the topics and the co-financial partner (found by the lab!); contact Directeur de thèse - andreas.elsaesser@umlp.fr

Then, prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online  before March 13th, 2026 Midnight Paris time!