The ExoMars mission in 2016 will soon experience a turning point. Indeed, Wednesday, October 19, the Schiaparelli capsule will land on the Red Planet. As for the satellite TGO, it will fit into the orbit of Mars to study its atmosphere. Franck Montmessin, CNRS research director at the laboratory atmospheres, backgrounds, space observations (Latmos), explains the scientific challenges of this mission. The ExoMars mission is among the most ambitious ever undertaken on the Red Planet. Its order to seek traces of past or present life. ESA offers us a video preview of this mission that proves exciting.

ExoMars mission: searching for life on the Red Planet

Nearly 13 years after the launch of Mars Express (June 2003), the European Space Agency (ESA) looks back to Mars with ExoMars 2016. This mission has two parts: the orbiter TGO (Trace Gas Orbiter) and the input demonstrator, descent and landing EDM (entry, descent and landing demonstrator Module) Schiaparelli more nicely called capsule.

If Mars Express was designed to map Mars, analyzing his basement and study its atmosphere, with the TGO ExoMars 2016, the study of the Red Planet will cross “unprecedented qualitative step”, explains Franck Montmessin , CNRS research director at the laboratory atmospheres, backgrounds, space observations (Latmos). It is the responsibility of science electric field sensor onboard Schiaparelli and co-leader of the Russian ACS instrument on board TGO. The orbiter mission is designed to study with unprecedented accuracy the composition of the Martian atmosphere and inventory “gases present in trace and determine their biological or geological origin.”

For this, the TGO embarks four instruments Nomad and ACS flagship mission instruments. The first is a set of spectrometers “measuring the spectrum of sunlight in different wavelengths (infrared, visible) and in the ultraviolet.” ACS is an instrument of the same type, also made up of three spectrometers “used to determine the spectrum of sunlight reflected from the Martian soil or through the Martian atmosphere as part of an occultation of the sun by the planet.”

Nomad and ACS, instruments to analyze the atmosphere

These two instruments are complementary to “the characterization of the Martian atmosphere, including the search of rare, particularly methane.” Although they are similar in operation but will differentiate the spectral range, they cover well that “they will have common recovery beaches and areas that will be specific to them.”

Measurement capability of the instrument in the ultraviolet Nomad “will go for ozone for example” while the ACS instrument will be more “effective in the range of near infrared and thermal,” which will ” detect not usually easy to see species “. Infrared heat will be “able to retrieve information on the carbon dioxide ‘, which consists mainly of the atmosphere, and” provide information on the temperature of the atmosphere at different altitudes. ”

What is lacking today in the knowledge of Mars, it is the “realization of a comprehensive inventory of species that might indicate a potential geophysical activity or any other process that could be a sign of activity March “. To date, we do not have the complete mapping of the gases present in the atmosphere. However, we roughly know what to expect thanks to our knowledge of the geological processes that occur on Earth. By terrestrial analogy, it is indeed “a priori possible to predict sulfur and hydrocarbon species such as methane for example.”

The TGO also features a sensor that will look if there is water in the surface of Mars at a depth of about 1 to 1.5 meters. The Mars Odyssey, NASA, did the same but “the TGO will do it from 5 to 8 times better in the legality of the measure.”