OrbitalHub

Wikipedia dixit:

“The stacked spacecraft will take seven years to position itself to enter Mercury orbit. During this time it will use solar-electric propulsion and nine gravity assists, flying past the Earth and Moon in April 2020, Venus in 2020 and 2021, and six Mercury flybys between 2021 and 2025.

The stacked spacecraft left Earth with an hyperbolic excess velocity of 3.475 km/s (2.159 mi/s). Initially the craft is placed in an orbit similar to that of the Earth. After both the spacecraft and the Earth completed one and a half orbits, it returns to Earth to perform a gravity-assist manoeuvre and is deflected towards Venus. Two consecutive Venus flybys reduce the perihelion nearly to Mercury distance with almost no need for thrust. A sequence of six Mercury flybys will lower the relative velocity to 1.76 km/s (1.09 mi/s). After the fourth Mercury flyby the craft will be in an orbit similar to that of Mercury and will remain in the general vicinity of Mercury. Four final thrust arcs reduce the relative velocity to the point where Mercury will “weakly” capture the spacecraft on 5 December 2025 into polar orbit. Only a small manoeuvre is needed to bring the craft into an orbit around Mercury with an apocentre of 178,000 km. The orbiters then separate and will adjust their orbits using chemical thrusters.”

Video Credit: ESA

ESA dixit:

“BepiColombo, the joint ESA-JAXA mission, comprises the European Mercury Planetary Orbiter and Japan’s Mercury Magnetospheric Orbiter, which will be transported to the innermost planet by the Mercury Transfer Module. The animation highlights several key milestones, including the solar array and antenna deployments once in space, through to the arrival at Mercury seven years later. When approaching Mercury, the transfer module will separate and the two science orbiters, still together, will be captured into orbit around the planet. Their altitude will be adjusted until the Magnetospheric Orbiter’s desired orbit is reached. Then the Planetary Orbiter will separate and descend to its lower orbit, and the two craft will begin their scientific exploration of Mercury and its environment.”

Credits Video: ESA

ESA dixit:

“[This is a] Video showing a test of the mechanisms steering the four solar electric propulsion thrusters on BepiColombo’s Mercury Transfer Module (speeded up by 20 times). The module will use a combination of electric propulsion and multiple gravity assists at Earth, Venus and Mercury to carry BepiColombo’s two scientificorbiters – ESA’s Mercury Planetary Orbiter and Japan’s Mercury Magnetospheric Orbiter – to the innermost planet in our Solar System.

The test is designed to demonstrate that the mechanisms can reach their full steering range. The thruster mechanisms control the steering of the spacecraft during the long thrust arcs of the 7.2 year cruise to Mercury and as such are used for navigation, attitude control, and reaction wheel off-loading. Together with the onboard software, the mechanisms will update the direction of the thrust vector every five minutes relative to the spacecraft’s evolving centre of gravity. The thrusters will be fired for several months at a time between the gravity assist flybys.

This particular test was conducted in April 2017, before the spacecraft was put into the composite stack configuration. The same test will be repeated again later in the year to verify performance after the stack level vibration test campaign.”

Video credit: ESA

ESA dixit:

“BepiColombo is Europe’s first mission to Mercury. It will set off in 2018 on a journey to the smallest and least explored terrestrial planet in our Solar System. When it arrives at Mercury in late 2025, it will endure temperatures in excess of 350 °C and gather data during its 1 year nominal mission, with a possible 1-year extension. The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). BepiColombo is a joint mission between ESA and the Japan Aerospace Exploration Agency (JAXA), executed under ESA leadership.”

Video credit: ESA