content long 24-January-2019 04:22:50

The ExoMars Rover Instrument Suite

RLS - Raman Laser Spectrometer

The Raman instrument provides a powerful tool for the definitive identification and characterisation of minerals and biomarkers. Raman spectroscopy is sensitive to the composition and structure of any mineral or organic compound. This capability provides direct information of potential organic compounds that can be related with present or past signatures of life on Mars as well as general mineralogical information for igneous, metamorphous, and sedimentary processes, especially water-related geo-processes.

The Raman laser spectrometer will be used:

  1. to identify organic compounds and search for signatures of life;
  2. to identify the mineral products and indicators of biological activities;
  3. to characterise mineral phases produced by water-related processes; and
  4. to characterise igneous minerals and their products resulting from alteration processes (e.g. oxidation).

Raman will also support the scientific measurements by correlating its spectral information with other spectroscopic and imaging instruments such as the MicrOmega Infrared Spectrometer. Furthermore, the Raman instrument is capable of measuring the sample at a fast-pace (within minutes) in order to release the selected sample for further analysis by other ExoMars instruments (e.g. the MOMA instrument).

The Raman instrument will collect and analyse the scattered light emitted by a laser on a sample (e.g. Martian rock). The spectral information received by the spectrometer (number of peaks, position and relative intensities) is determined by the molecular structure and composition of a compound, enabling the identification and characterisation of the Martian molecules, minerals and rocks. This method allows analysing the sample in a non-destructive way, which means that the sample remains intact for further analysis by other instruments. 

In-situ analysis of basalt rocks using a Raman spectrometer.
Credit: ESA-Raman team / AMASE

The Raman instrument consists of three main units, the optical head, the spectrometer unit and the electronics unit, which are interconnected by an optical and electrical harness.

The flight model of the Raman laser spectrometer weighs slightly over 2kg in total including all necessary interconnecting harnesses, and consumes as little as ~30W of electrical power during operation.


Raman and Mossbauer Spectrometers during field tests. Credit: ESA-Raman team

Instrument update

The instrument is currently in its design phase during which several sub-system prototypes and breadboards have been established and tested. Testing includes breadboard testing under simulated Martian conditions, sub-system prototype performance, environmental assessment (thermal, vibration and radiation tests) as well as field tests.


RLS participants
Principal Investigator
Fernando Rull Perez, Centro de Astrobiología, Unidad Asociada (CSIC-UVA), Spain

Co-Principal Investigator
Sylvestre Maurice, Laboratoire d'Astrophysique - Observatoire Midi-Pyrénées (LAOMP), France
ESA contact
ExoMars instrument system engineer
Frederic Didot, Directorate of Science and Robotic Exploration, European Space Agency
More instrument details
The Raman Laser Spectrometer for the ExoMars Rover Mission to Mars
Rull, F., et al., Astrobiology, July 2017, 17(6-7), 627-654


Last Update: 25 August 2017

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