A joint venture with Russia, the ExoMars Trace Gas Orbiter (TGO) is set to launch atop a Proton rocket from Baikonur, Kazakhstan, on Monday.
The satellite will try to detect and characterise the marginal constituents of the planet’s atmosphere.
A key quest is to understand methane, a gas that has an unexpected persistence and which some have speculated could hint at the presence of microbial life.
Lift-off of the Proton is scheduled for 15:31 local time (09:31 GMT).
“We’ve had a good launch campaign to date – no real issues,” said Walter Cugno from the lead European contractor, Thales Alenia Space.
“All the preparation milestones have been achieved as per the nominal schedule,” he revealed.
t will take 12 hours for the Proton’s Breeze-M upper-stage to boost the ExoMars TGO into just the right trajectory to go to the Red Planet.
Controllers at European Space Agency’s Operations Centre in Darmstadt, Germany, expect to pick up a signal from the satellite shortly after it has been released on to this cruise path, at 21:28 GMT.
The journey time to Mars is seven months. Three days out from arrival, on 16 October, the satellite will release a small landing module known as Schiaparelli.
Once on the surface, on 19 October, its aim is to operate a few science instruments, but engineers are primarily interested to see how the module performs during the entry, descent and touchdown.
“This technology development is very important,” said Esa’s director of science, Prof Alvaro Gimenez.
“If you want to be a partner in the future on more missions to Mars, you have to demonstrate your ability to land. If you can’t, you are not at the right level. We have to show we can do it ourselves.”