BepiColombo off to a 7-year trek to Mercury

A joint European-Japanese mission, BepiColombo, to the tiniest planet, Mercury was  blasted off from French Guiana on Oct. 19. BepiColombo will spend seven years cruising toward its target, where it will separate into two spacecraft and orbit Mercury for a year — or two, if the mission is extended.

After the launch, European and Japanese space agencies confirmed that the Ariane 5 rocket successfully lifted the spacecraft which carried two probes into orbit on Saturday. The whole mission cost the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) almost $2 billion.

About the Mission

The BepiColombo spacecraft will have to follow an elliptical path that involves a fly-by of Earth, two of Venus and six of Mercury itself so it can slow down before arriving at its destination in December 2025. 

Then finally, in December 2025, BepiColombo will split into its two components, the Mercury Planetary Orbiter built by the European Space Agency and the Mercury Magnetospheric Orbiter built by the Japan Aerospace Exploration Agency. The ESA-developed Bepi will operate in Mercury’s inner orbit, and JAXA’s Mio will be in the outer orbit to gather data that would reveal the internal structure of the planet, its surface and geological evolution.

The probes are designed to cope with temperatures varying from 430 degrees Celsius (806 F) on the side facing the sun, and -180 degrees Celsius (-292 F) in Mercury’s shadow.

As it travels, one instrument on board will be making the most precise measurements to date of Mercury’s and Earth’s orbits around the sun. With these measurements, scientists will try to find any shortcomings in Einstein’s theory of general relativity. Upon reaching the destination, the probes and other instruments aim at solving lingering mysteries surrounding Mercury. They also aim at knowing more about the formation of our solar system.

Those spacecraft will become the first to study Mercury since the only previous orbiter, NASA’s MESSENGER, ended its mission in 2015 after four years at the tiny planet. 

Mercury’s extreme temperatures, the intense gravity pull of the sun and blistering solar radiation make for hellish conditions.

Mercury, which is only slightly larger than Earth’s moon, has a massive iron core about which little is known. Researchers are also hoping to learn more about the formation of the solar system from the data gathered by the BepiColombo mission.