Since the beginning of the space era, mass spectrometry is a reliable technique for in situ characterisation of ions and molecules detected in various planetary environments. It has been crucial for the analysis of compounds found in ocean worlds vicinity, such as Enceladus’ plumes. The study of the chemical complexity of the environments of the ocean worlds would benefit from the design of a new generation of instruments to allow an exhaustive characterization of them. Among the many objectives of space missions is the search for potential chemical biosignatures on ocean worlds. The precise and unequivocal identification of these biosignatures would be done by mass spectrometers able to perform analyses with a high mass resolving power and high mass accuracy. Efforts are on-going to develop for future space explorations High Resolution Mass Spectrometer instruments (Arevalo et al., 2020) with a space qualified version of the Orbitrap mass analyser, the CosmOrbitrap. Coupled with a commercial laser ionization source, it has demonstrated promising performances in positive ion mode in terms of mass resolution, mass accuracy and isotopic ratio measurements. This work focuses on the performance achievements with the negative ion mode recently implemented. A study has been performed with a ruggedized spaceflight CosmOrbitrap mass analyser at technical readiness level of 5 at the dual ion polarity to determine the efficiency of the instrument to detect and identify organic molecules of prebiotic interest when embedded in magnesium and sodium salts matrix. These results illustrate the potential of the CosmOrbitrap mass analyser for future in situ analysis of ocean worlds as Europa and Enceladus.