The ExoMars mission: a primer
October 19, 2016
Two important pieces of equipment will be on board the Russian rocket when it blasts off from Kazakhstan:
1. An orbiter
This glorified box with solar-panels and a dish on top will do loops around Mars - twice per day. It'll be "sniffing" the atmosphere for traces of methane gas all the while. Why methane? Because methane is usually the result of a biological interaction (read "LIFE!") - at least here on Earth. That's the whole purpose of the ExoMars mission: to search for signs of life, past or present, on the red planet. Methane was detected a few years ago by a NASA rover, so it is there. The orbiter will try to sniff out the richest pockets of it.
2. A lander
Shaped like a Hershey's kiss, this module will parachute and then reverse-rocket its way down onto a wide, flat Martian plain. It will then have just four Martian days to monitor various things - like how much dust is in the air (it will land during dust storm season), what the weather's like and how electrical the air is. The lander will beam this data back to the orbiter above, which will then relay it back to Earth. Then, after four days, the lander will die.
If it seems like a waste, the lander's real role is to play crash-test dummy. This is a trial-run, a bit like inspecting the runway before landing a plane on it. Or a rover.
3. The ExoMars rover
The rover is 300 kilos (650 pounds), has six wheels and sports a dual camera that will take wonderfully high-res panoramic pictures in true color. Yippee!
More importantly, it has a drill. The drill sink up to two meters (6.6 feet) into Mars' surface, retrieving "cores" of the soil. Since the rover is never, ever coming back to Earth, that soil will be analyzed inside the rover, and the data will be beamed up to the orbitor and then back home.
The most important sensor: the organic molecule analyzer. That's the tool that will potentially find signs of life. (It's being developed right now by the Max Planck Institute for Solar System Research in Göttingen in central Germany, and one component, a laser, will be built in Hanover by the Laser Zentrum.)
The time-frame
To sum up, here's the ExoMars plan:
The orbiter/lander launch on March 14, 2016.
They then fly through space, reaching Mars in October 2016.
Four days later, the lander 'dies.' But the orbiter lives on and keeps on orbiting.
In 2018 (or maybe 2020), a rocket takes off with the rover inside.
Tghe rover inside it flies through space (inside a spacecraft) and lands on Mars in 2019 (or 2021).
Then the drilling begins.