content long 19-January-2018 01:57:01

The ExoMars Rover Instrument Suite

ISEM - Infrared Spectrometer for ExoMars

ISEM will be part of the instrument payload on the ExoMars Rover, scheduled for launch in 2020.

This instrument will be a mast-mounted infrared spectrometer, designed to determine the major mineral composition of distant rocks, outcrops, and soils. ISEM will be used to help scientists decide which surface targets the ExoMars Rover should approach for a more detailed investigation.

ISEM is mounted on the Rover's mast together with the PanCam High-Resolution Camera (HRC) and Wide Angle Cameras (WAC). ISEM can be pointed to the desired direction in azimuth and elevation by means of the mast's pan and tilt mechanism. During a typical operation, the PanCam WAC, which has a field-of-view of 37° × 37°, will image a large panorama, while the PanCam HRC, with a field-of-view of 5° × 5°, will image a few targets within this panorama at high resolution. At the same time, ISEM, which has a field-of-view of 1°, will measure the infrared characteristics of these same targets by recording the spectra of solar light reflected from the planet's surface and modified by absorption and scattering in the atmosphere. Using the combined visual plus spectroscopic characterisation, the science team on Earth will be able to help plan Rover operations by choosing the most promising targets for drilling.

The spectrometer will also be used to identify and map the distribution of rocks that have had a change in composition caused by chemical weathering due to interaction with water-bearing ices, liquids, and vapours. This process is known as aqueous alteration. Of particular interest are measurements that will allow scientists to distinguish between various classes of silicates, oxides, hydrated minerals and carbonates.

ISEM will also study variations of the atmospheric dust properties and of the gaseous composition of the atmosphere.

The main science objectives of ISEM are:

  • To search for and study minerals bearing hydroxide (OH) or water (H2O)
  • To carry out a geological investigation and study of minerals and rocks in the thin uppermost layer of the martian surface
  • To identify and map the distribution of any aqueous alteration products on the landing site
  • To perform a real-time assessment of the composition of the surface in selected areas, to support the identification and selection of the most promising drilling sites
  • To study variations of the properties of atmospheric dust and of the gaseous composition of the atmosphere, in as far as this is possible with limited number of observation cycles

ISEM is an infrared acousto-optical tunable filter (AOTF) spectrometer, operating in the spectral range 1.15 μm to 3.3 μm with a spectral resolution better than 25 cm-1, and a field-of-view of 1°. The instrument, which has a mass of 1.3 kg, consists of two blocks; the optical box, mounted on the mast of the Rover so that the field-of-view of ISEM is kept within the field-of-view of the PanCam HRC, and the electronics box, mounted inside the thermo-stabilized compartment of the Rover.

ISEM participants
Principal Investigator
Oleg Korablev, Space Research Institute (IKI), Moscow, Russia

Project manager
Andrei Ivanov, Space Research Institute (IKI), Moscow, Russia

Russian Payload Manager
Daniel Rodionov, Space Research Institute (IKI), Moscow, Russia
ESA contact
ExoMars instrument system engineer
Andrew Ball, Directorate of Science and Robotic Exploration, European Space Agency
More instrument details
Infrared Spectrometer for ExoMars: A Mast-Mounted Instrument for the Rover
Korablev, O.I., et al., Astrobiology, July 2017, 17(6-7), 542-564


Last Update: 25 August 2017

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