ExoMars Trace Gas Orbiter

Key facts

Mission & specifications

Mission

The ExoMars Trace Gas Orbiter is a European–Russian spacecraft sent to sniff the Martian atmosphere for the faint chemical hints of present-day activity — whether geological or, conceivably, biological. Launched on 14 March 2016, it arrived at Mars on 19 October 2016 and spent more than a year delicately aerobraking, dipping into the upper atmosphere on each orbit to shed energy and settle into a circular 400-kilometre science orbit by 2018. Its instruments are tuned to detect gases present at just parts per billion, above all methane — a gas that on Earth is largely produced by life, and whose reported but disputed presence on Mars has tantalised scientists for years. TGO's highly sensitive surveys have so far found no clear sign of methane in the bulk atmosphere, sharpening one of the planet's enduring puzzles, while also mapping subsurface hydrogen — a proxy for buried water ice — to help find safe, resource-rich sites for future missions. The orbiter carried the Schiaparelli demonstration lander, which was lost during its descent in October 2016 when a software fault made it think it had already landed, a hard lesson dissected in detail afterwards. Beyond its own science, TGO serves as a vital data-relay satellite, carrying signals between Earth and the rovers working on the surface below, including NASA's Perseverance.

1. 2016Launch toward MarsLaunch

   A Proton rocket sends the European–Russian orbiter and the Schiaparelli lander toward Mars.

2. 2016Mars orbit insertionArrival

   TGO enters orbit; the Schiaparelli demonstration lander is lost during its descent.

3. 2018Science orbit reachedMilestone

   More than a year of aerobraking circularises the orbit and full atmospheric science begins.

4. 2019Sensitive surveys find little methaneMilestone

   Highly sensitive measurements detect no clear methane, deepening a long-standing Martian puzzle.

Images

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