The European Space Agency is dispatching an experimental probe on the final leg of its mission to land on Mars.
The Schiaparelli space lander is to separate from its mother ship at 14.42 Sunday in preparation for a controlled descent to the red planet on Wednesday.
The probe will take images of Mars and carry out scientific measurements on the surface, but its main purpose is to test technology for a future European Mars rover.
The ESA's last attempted Mars landing with the Beagle 2 rover failed in 2003.
Schiaparelli's mother ship will remain in orbit to analyse gases in the Martian atmosphere to help answer whether there is - or was - life on Mars.
The ExoMars mission is a joint venture between ESA and Russia's Roscosmos space agency.