Later today, the ExoMars landing demonstrator will detach from the primary satellite and descend to the surface of the Red Planet.
Once it arrives, the Schiaparelli landing demonstrator will only function a couple of days while transmitting weather reports from Mars: wind speed, humidity, and temperature. If all goes well, it will also upload photos made during the 6-minute descent. But the primary function of the 600-kilogram lander (weighing only 200 kilograms on Mars) is recording data during the descent through Mars' thin atmosphere.
The European Space Agency (ESA), that works together with the Russian space agency Roscosmos says that ExoMars marks the transition from remote observation (by MarsExpress from 2003) to on-surface and sub-surface exploration (by the ExoMars Rover in 2018).
The largest part of the satellite, the Trace Gas Orbiter (TGO), will orbit the Red Planet and transmit data from Schiaparelli and later missions to Earth. In addition, it will map the presence of methane.
The previous ESA Mars mission MarsExpress detected traces of methane (CH4) in the thin atmosphere (air pressure less than 1% of the Earth atmosphere). That discovery aroused attention because, on Earth, methane is regarded as an indication of biological activity. Only very little methane comes from geological processes like in volcanoes.
So now the TGO should help to establish the origin of methane: biological (life on Mars!) or geological.
The landing demonstrator has been named after the 19th century Italian astronomer Giovanni Schiaparelli who first discovered ‘canali' on the surface of Mars - an indication for water. Scientists now think that water has played a significant role in shaping the planet’s surface. The current surface, however, is dry and barren. The thin atmosphere consists mainly of CO2 (95%), and the temperatures range from -133 to +27 Celsius.