Spacecraft bound for Mercury faces ‘tricky’ arrival

A European and Japanese spacecraft will arrive at Mercury on Thursday after an eight-year, 10-billion-kilometre journey, navigating through high-risk maneuvers to study the challenging planet. Set off in 2018, the BepiColombo mission aims to release two probes into orbit around the smallest and least understood planet in our Solar System for detailed study.

The European Space Agency (ESA) dubbed the arrival phase the "most operationally challenging planetary arrival sequences ever attempted" due to Mercury's extreme environment near the Sun. Its weak gravitational pull makes it difficult for spacecraft to approach without danger, as its mass is only slightly larger than the Moon.

The spacecraft executed nine flybys to adjust its trajectory and speed, covering more than 10 billion kilometres. On Thursday, the two attached probes will separate from the transfer module, marking the equivalent of launching a new spacecraft around another planet. From April, the Mercury Planetary Orbiter (MPO) will study Mercury with unprecedented precision, while the Japanese Mercury Magnetospheric Orbiter (Mio) will focus on the planet's space environment and magnetic field, orbiting as far as 11,000 km away.

Mercury's distance from Earth and the Sun creates communication challenges, with a 30-minute delay between ground commands and the spacecraft's execution. Many systems are being tested for the first time in this harsh environment, with uncertainties about what may go wrong, although the team is prepared for the unexpected. BepiColombo's sixteen instruments and 1.7 billion-euro budget will bring unprecedented views of Mercury, opening a new chapter in our understanding of the solar system.