The ExoMars mission is carried out by the French CNES and the European ESA in co-operation with Roscosmos, and is articulated in two missions which will be successively launched by two Russian rockets Proton.
The ExoMars 2016 mission will put into orbit around Mars a satellite, "Trace Gas Orbiter" (TGO), to study the atmosphere of Mars and its evolution, and will be used as relay of telecommunications towards the Earth for the landers. The satellite will study with Russian and Europeans instruments the gases present at the state of traces in the Martian atmosphere such as methane; which is suspects to have a bacteriological origin.
The satellite will release an entry and descent demonstrator fitted with parachute, "Schiaparelli", equipped with sensors to measure the performances during the descent and at the time of the landing. Without solar panels, it will only function 4 terrestrial days on its own batteries. It will collect environmental data.
The ExoMars 2018 mission will deposit a Russian lander and a European vehicle on Mars. The of 310 kg lander, equipped with Russian and European instruments will take measures of the environment during one Martian year - 687 terrestrial days. It is dedicated to the study of the ground and the close basement, being able to drill 2 meters deep.
It will transport a complete set of analytical instruments dedicated to exobiology and geochemistry research, named Pasteur. It will cross several kilometers in the search of signs of past or present life, collecting and analyzing samples of the ground preserved of the radiations and oxidants which destroy the organic matter. It will be the first mission since Viking in 1977 that tries to detect traces of life, present or past, on Mars - all the other missions only aimed at studying if the conditions for life were met on Mars.
The European vehicle will carry instruments of the CNES like MicrOmega, a spectrometer able to capture images in the visible and the infra-red for mineralogical studies; Wisdom, a radar to study the near underground in order to characterize its structure. The mission is titled: "In search of the traces of Martian life".
Three other instruments with French contribution, MOMA, RLS and CLUPI, are under the responsibility of other ESA Member States.
