Last Friday, 10 April 2020, the joint Euro-Japan space mission passed by Earth, marking a key milestone in its seven-year journey to reach Mercury. On Friday, BepiColombo reached a minimum distance of around 12,700 kilometers from the surface of Earth and flew by in the opposite direction to our planet’s orbit, causing the spacecraft to slow down.
The BepiColombo spacecraft was launched in October 2018 and will spend seven years cruising space towards its target, Mercury. It will then orbit Mercury for a year or two, this is in order to gain data and insight into the unknown factors of the innermost planet. Named after Italian scientist Giusseppe “Bepi” Colombo (1920-1984), the €650m mission includes two scientific satellites and a transporter, both the Japanese Mercury Magnetospheric Orbiter (MMO, now known as Mio) and the European Mercury Planetary Orbiter (MPO), which have both been joined to a propulsion module, known as the Mercury Transfer Module (MTM) for the duration of the mission to push them into the correct orbits.
Since it’s launch in 2018 the spacecraft has completed one and half loops around the sun, travelling at a distance of approximately 1.4 billion km. By the time BepiColombo reaches Mercury, it will have completed 18 loops and covered more than 8.5 billion km. Bepi is now making its way towards Venus, where it will operate two flybys in October of this year and of August 2021, and then will arrive at Mercury by 2025. In total the BepiColombo spacecraft will follow an elliptical path in which includes a fly-by of Earth, which took place on Friday, then two of Venus and six of the planet Mercury itself in order for the craft to slow down enough before landing on Mercury on the 5th December 2025.
The craft's path with allow it to complete one fly-by of Earth, two of Venus and finally six of Mercury before it lands on the planet
Once Bepi has reached Mercury the European and Japanese probes will then separate from each other in order to undertake different roles. Japan’s MMO (Mio) will study Mercury’s magnetic field. By examining the field’s behaviour and how it interacts with the “solar wind”, the mass volume of particles that flow from the sun. The “solar wind” interacts with the planet’s fragile atmosphere, causing atoms to whip into a tail that can reach far into space. Europe’s MPO is then designed to map out Mercury’s terrain, collecting data on the planet’s surface structure, composition, craters, origins and generate height profiles. While also trying to make a sense of the interior of the planet. The European Space Agency (ESA) states that the mission could be one of it’s most challenging due to the extreme temperatures, solar radiation and the intense gravity pull from the sun, making the conditions of the planet dangerous. Due to this, the probes have been designed to cope with the planet's temperatures, varying from 430 degrees Celsius on the side of the planet facing the sun and -180 degrees Celsius in the shadows of the planet.
The probes have been designed to withstand temperatures ranging from 430 degrees to -180 degrees Celsius
Through these methods and the data gathered by the BepiColombo mission through its observations, researchers hope to learn more about Mercury’s massive iron core with which little is known about and to gain more knowledge about the formation of the solar system.