BepiColombo

Liftoff! A quick primer on the latest ESA/JAXA mission

An Ariane 5 rocket successfully launched the BepiColombo mission, a joint ESA-JAXA venture to Mercury, the closest planet to our Sun. This beautiful night launch marked the first time the Europeans have led a mission to Mercury.

Liftoff! Night launches are always spectacular to watch.

The BepiColombo mission is unique in that two spacecraft launched and will study Mercury simultaneously. Science returns won’t start to roll in until 2026, which underscores how difficult it is to go closer to the Sun. It’s counterintuitive, but a spacecraft requires more energy to reach Mercury than Pluto.

After seven years of constant braking with an Ion engine, BepiColombo will arrive in orbit around Mercury. At that point, the spacecraft will pick up where the NASA MESSENGER mission left off, studying everything from the exosphere to volcanic activity.

Artist renditions of an Earth and Mercury flyby.

The two orbiters, the Mercury Planetary Orbiter, and the Mercury Magnetosphere Orbiter will remain attached until October of 2025. Before the arrival at Mercury, BepiColombo will perform nine planetary flybys, six of which will be at Mercury. The spacecraft will fly within 200 km (~125 miles) of Mercury during these maneuvers. These gravity-assist flybys will complement the solar electric ion thrusters, helping guide the spacecraft into a stable orbit around Mercury.

BepiColombo will travel 9 billion kilometers (nearly 5.6 billion miles) and will reach a top speed of 60 km/s (that’s a blistering 134,216 mph) during its seven-year journey to Mercury. Here’s to a successful cruise portion of the mission and to incredible science that we can expect coming back to Earth in 2026.

Learn more about the mission here and follow the mission milestones via Twitter.