NASA is providing a launch vehicle, four science instruments and a communication system for the mission.
The mission's entry, descent and landing component is a technology test to lay the groundwork for sending future robotic rovers to Mars.
The orbiter would map the variable distributions of trace gases in Mars' atmosphere, including methane and its isotopes.
Detection of other gases (e.g., sulfur dioxide) would provide clues as to whether their release is volcanic, tectonic or biological in nature.
