It has to be one of the slowest parking attempts ever made, but ESA's ExoMars Trace Gas Orbiter (TGO) has completed a daring maneuver that saw it surfing the outer layers of the Martian atmosphere for 11 months. The purpose of the exercise was to gradually lower the unmanned probe's trajectory to place it in a planet-hugging, near-circular orbit at an altitude of about 400 km (250 mi), allowing the spacecraft to begin its mission to study trace gases on Mars as well as act as a communications relay between Mars surface rovers and Earth.

Launched on March 14, 2016 atop a Proton-M rocket from the Baikonur Cosmodrome in Kazakhstan, the ExoMars Trace gas Orbiter arrived at Mars on October 19 of that year. However, the spacecraft was in a highly elliptical four-day orbit at an altitude ranging from 200 to 98,000 km (125 to 61,000 mi), which was completely unsuitable for its mission.