ExoMars Trace Gas Orbiter, a Mars methane mission

ExoMars mission concept

The ExoMars Trace Gas Orbiter mission is a joint endeavour by the European Space Agency (ESA) and its Russian equivalent, RosCosmos. It demonstrates key technologies for future flight and in-situ exploration missions and makes important scientific discoveries, fundamental to the exploration of Mars.

It will also act as a data communications relay for other future Mars missions.

The ExoMars programme consists of two missions.

• The ExoMars Trace Gas Orbiter mission consisting of an orbiter and a lander demonstrator (EDL), which was launched in 2016 by a Proton rocket from Kazahkstan.
• A rover and a platform containing European (ESA) and Russian scientific instruments, which will be launched by another Proton rocket.

ExoMars Trace Gas Orbiter (TGO) launch and orbit altitude

The spacecraft is designed, built and integrated by ESA and includes an Orbiter which carries the scientific trace gas payload instrumentation and an Entry, Descent and Landing (EDL) Demonstration Module.

The spacecraft was launched in March 2016 by a Proton launch vehicle and arrived at in October 2016. The EDL Demonstration Module was released a few days before the critical Mars Orbit Insertion manoeuvre by the orbiter.

The orbiter is on a circular orbit with an altitude in the range of 350 to 420 km.

The science operations phase began in mid-2017. The nominal science phase lasted for one Martian year. The mission is still running. The orbiter also serves as a communications and data relay channel for different assets on the surface of the planet.

Science objectives of the ExoMars spacecraft

Observations of the planet Mars, both from satellites in orbit around Mars as well as from Earth, have indicated the presence of methane. Photochemical models cannot explain the presence of methane and its variations in space and time.

These observations raise questions about:

• the origin of methane
• the possible presence and variation of other trace gases
• the processes taking place on and below the surface and in the atmosphere of Mars
   

These questions lead to the following scientific goals:

1. Detect a broad suite of atmospheric trace gases and key isotopes
2. Characterise the spatial and temporal variability of methane and other key species (solving the "methane mystery")
3. Localise sources and derive the evolution of methane and other key species and their possible interactions
4. Image surface features possibly related to trace gas sources and sinks