lander Schiaparelli is due to touch down Wednesday as part of the ExoMars missions
-- a joint venture between the European Space Agency (ESA) and Russian state corporation Roscosmos.
Schiaparelli's companion ship -- the Trace Gas Orbiter
-- will stay in orbit, trying to find out more about methane and other gases on Mars that could be signatures of life, or geological processes.
In 2014, NASA's Curiosity rover detected a large spike in the amount of methane
. ESA scientists hope that the ExoMars missions can shed light on what might be causing it.
Schiaparelli is designed to be a test flight for another ExoMars venture -- a 2020 launch that will send a rover to Mars. But Schiaparelli will also operate for a few days, measuring wind speed, temperature, humidity, pressure and the strength of electric fields on the planet's surface. It will also collect a series of images in the final stages of descent.
Engulfed by dust storms
Senior science adviser at ESA, Mark McCaughrean, told CNN that the lander was entering a world of dust storms. It is thought that dust particles bumping into each other create a static charge that lifts even more dust, creating clouds that can engulf the whole planet. It is this electric field that they want to investigate, McCaughrean explained.
Getting there is a major challenge though. The spacecraft cannot be steered in real time and plunges through the thin Martian atmosphere at 1,700 kph (more than 1,000 mph), protected by its heat shield.
McCaughrean said a parachute would be deployed when Schiaparelli is still moving at 250 kph (150 mph) before thrusters fire for the last 30 seconds of descent. The probe also has a crumple zone to help cushion the landing.
Mission controllers will be hoping for better fortune than in 2003 when contact was lost with an ESA Mars probe called Beagle 2 during a planned landing on Christmas Day. Only last year, images from NASA's Mars Reconnaissance Orbiter showed that the craft had landed successfully
but its solar panels had failed to deploy properly.
'Mars is hard'
Beagle's accompanying orbiter, Mars Express, continues to send back data from Mars, recently picturing what ESA says is the remnants of ancient glaciers
"Mars is hard," said McCaughrean. "Mars has a very thin atmosphere which makes it very difficult to get down to the surface... it's been a graveyard for previous missions.
"Having been through two Rosetta landings it's going to be nerve-wracking but I'm really thrilled about going back to get it right this time. We're back to prove we have the ability," he said.
ESA has greater ambitions for the 2020 mission. The rover will be able to drill two meters into the Martian surface to look for signs that life may exist today or sometime in the past.
People have long wondered whether our neighboring planet could have harbored life. The landing craft is named after the Italian astronomer Giovanni Schiaparelli who mapped Mars in the 19th century and whose description of "canali" on the surface sparked a debate about whether they could have been created by Martian inhabitants. Modern observations showed that these channels never existed.
The two ExoMars missions, which McCaughrean said will cost more than a billion euros ($1.10 billion), come at a time of renewed interest in the Red Planet.
Writing for CNN, US President Barack Obama spoke
of America's goal to send humans to Mars by the 2030s "with the ultimate ambition to one day remain there for an extended time."
Human mission ahead?
If successful, Schiaparelli will join two active NASA rovers on the Martian surface -- Curiosity which arrived in 2012 and Opportunity which has been returning images for more than 12 years. Spirit's mission finished in 2011.
MAVEN has already discovered that solar winds have stripped gases like oxygen and carbon dioxide from the planet, and found auroras on Mars that are similar to the northern lights on Earth.
NASA is planning a new rover mission
that will scour the surface for the signs of life. It is due to land in February 2021.
President Obama said exploring Mars would "require continued cooperation between government and private innovators" and independent companies are already making plans.
says it will start training astronauts in 2017 in preparation for a launch in the mid-2020s, and Space X has tested a rocket
it plans to use for a future mission to Mars.