Japan’s Aerospace Exploration Agency (JAXA) announced on May 26 via its official Mercury Magnetospheric Orbiter (MMO) account on X that BepiColombo will enter Mercury orbit on November 21, 2026. The joint ESA/JAXA mission — comprising the Mercury Transfer Module (MTM), ESA’s Mercury Planetary Orbiter (MPO), and JAXA’s MMO — has been in transit since its October 2018 launch, making one Earth flyby, two Venus flybys, and six Mercury gravity-assist loops. The arrival is eleven months later than originally planned, after a thruster anomaly discovered in 2024 forced mission controllers to revise the orbital approach trajectory. Following orbit capture, the MMO is scheduled to detach from the MTM on December 10, with both orbiters expected to begin science operations a few weeks after that.
BepiColombo is humanity’s third mission to Mercury, following Mariner 10 in 1973 and Messenger in 2004, and the first to deploy two independent orbiters simultaneously. Mercury remains among the solar system’s least-studied bodies: its proximity to the Sun makes navigation treacherous, surface and near-space temperatures are extreme, and the Sun’s glare limits ground-based telescope observations. To survive the environment, ESA’s MPO is equipped with 94 kilograms of insulation and a radiator system. Once operational, the MPO and MMO will carry instruments designed to map Mercury’s interior structure, magnetic field, and magnetosphere in detail — data that researchers hope will shed light on how a planet so small and so close to the Sun retains a magnetic field at all.