After traveling together as a conjoined spacecraft for eight years, the BepiColombo twin orbiters will finally be forced to separate as they arrive at their destination.
BepiColombo, a joint mission between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), is gearing up for a challenging separation sequence that will take it from one spacecraft to two. The spacecraft’s arrival at the closest planet to the Sun will be broadcast live on ESA’s YouTube Channel on September 3 at 6:45 a.m. ET, and you can also tune in through the feed below.
BepiColombo was originally scheduled to reach Mercury in December 2025, but the twin probes suffered a glitch that prevented it from operating at full power. The spacecraft was forced to follow a different trajectory to the planet, delaying its arrival.
Separation anxiety
BepiColombo launched in October 2018 on a mission to explore Mercury’s surface and interior, along with the planet’s magnetic field. The twin probes, ESA’s Mercury Planet Orbiter (MPO) and JAXA’s Mercury Magnetosphere Orbiter (MMO), launched together on a single spacecraft but each is designed to enter its respective orbit around Mercury later this year.
Following an arduous journey through space, the mission is about to initiate its arrival phase at the closest planet to the Sun. On Thursday, ESA’s Mercury Transfer Module (MTM) will separate from BepiColombo’s two science orbiters. The transfer module carried the two science orbiters on their trek to Mercury. Once at the planet, however, the two orbiters are set to go off on their own as a single stack moving via free-fall.
MTM’s separation is the first major step to a meticulous sequence of events designed to initiate the dual mission. After MTM separates from the twin probes, they will both lock into a polar orbit around Mercury as a single stack using MPO’s chemical thrusters.
In December, the small thrusters on MPO will be used to deliver the probe to its orbit. There, the probe will eject its once-conjoined twin and spin up. MPO will then discard its sunshield and continue its own orbit around Mercury.
BepiColombo is only the third spacecraft to visit Mercury, as the Sun’s powerful gravitational pull makes it difficult to reach the elusive planet.
The mission carried out its first flyby of the planet in October 2021 and has been returning gorgeous close-up images of the solar system’s smallest planet, as well as valuable data about the mysterious orb.
Yes, it was a glitchy journey to Mercury, but hopefully, it’ll be smooth sailing from here on in.
