BepiColombo

BepiColombo

Spacecraft· ESA / JAXAactive

BepiColombo — twin orbiters en route to Mercury orbit insertion.

Open in 3D viewSee BepiColombo in the live, interactive 3D map

Key facts

Current speed
55.6 km/s
Distance from Sun
0.332 AU
Status
Active
Launched
2018

Mission & specifications

Mission

Operator
ESA / JAXA
Launched
October 20, 2018
Status
Active

Trajectory

Current speed
55.6 km/s
Distance from the Sun
0.332 AU
Distance from Earth
1.32 AU
Distance from Mercury
6,683,024 km

Mission

BepiColombo is a joint European and Japanese mission to Mercury, the most ambitious study of the innermost planet since MESSENGER. Launched on 20 October 2018, it is really three spacecraft in one stack: ESA's Mercury Planetary Orbiter, Japan's spin-stabilised Mio orbiter, and a Mercury Transfer Module that carries them both using efficient solar-electric ion engines. Reaching Mercury is deceptively hard — a probe falling toward the Sun gains enormous speed, and must shed it to be captured — so BepiColombo follows a long, looping cruise braked by nine planetary flybys: one of Earth, two of Venus and six of Mercury itself. Along the way its flyby cameras have already returned striking views of Mercury's cratered surface. Once in orbit the two science orbiters will separate to study the planet from complementary vantage points, mapping its surface and composition, probing its surprisingly large iron core and its puzzling magnetic field, and sampling the thin, dynamic exosphere and surrounding space environment. The mission is named after Giuseppe 'Bepi' Colombo, the Italian scientist who explained Mercury's curious 3:2 spin–orbit resonance and devised the multi-flyby trajectory that let Mariner 10 visit the planet three times. After a journey of more than seven years, BepiColombo is due to settle into orbit around Mercury in late 2026.

  1. 2018Launch toward MercuryLaunch

    An Ariane 5 sends the stacked European and Japanese orbiters on a seven-year cruise.

  2. 2020Earth gravity assistMilestone

    A flyby of home bends the trajectory inward toward the inner Solar System.

  3. 2021First Mercury flybyFlyby

    The first of six passes of Mercury begins braking the spacecraft into the planet's gravity well.

  4. 2025Final Mercury flybyFlyby

    The last gravity assist sets up arrival, returning close-up views of the cratered surface.

  5. 2026Mercury orbit insertion (planned)Arrival

    The two science orbiters separate to begin mapping Mercury from complementary orbits.

Images

The BepiColombo Mercury orbiters
NASA (public domain) · Wikimedia Commons

Images from open archives · credit shown per image