BepiColombo Mission To Mercury Launches Tonight

This illustration shows the BepiColombo dual-spacecraft approaching Mercury, where the two orbiters will separate and study the planet from their dedicated orbits. With its solar wings deployed, the spacecraft is 98 feet long (30 meters). ESA

Wanna watch a rocket launch to Mercury? It happens tonight when the joint European-Japanese BepiColombo mission blasts off at 8:45 p.m. (Central Time) from Europe’s Spaceport in French Guiana. Live transmission starts a half-hour before at 8:15 p.m. See it happen before your eyes here.

This  Europe’s first mission to Mercury and comes on the heels of America’s MESSENGER spacecraft, the first probe to orbit the planet (2011-2015) and map it in detail. You wouldn’t think it would take very long to get to Mercury since it’s only about 48 million miles away (Jupiter’s almost half a billion!), but it’s not as simple as it looks. You have to decelerate a spacecraft for it to “fall” inwards toward the sun, and you have to do it without packing excessive amounts of fuel. That’s where other planets can provide a crucial boost.

You’ll get dizzy watching, but here’s an animation of BepiColombo’s trajectory from Oct. 20, 2018 to Nov. 2, 2025. The spacecraft is the pink path. JPL/NASA

Just as we can use a planet’s gravitational pull to change course and accelerate as the Voyager spacecraft did en route to the outermost planets, you can approach a planet on a different course and decrease a spacecraft’s speed. MESSENGER had to fly by Earth once, Venus twice, and Mercury itself three times before it could approach the planet slowly enough to drop into orbit. Launched in 2004, the mission achieve orbit until 2011.

BepiColomo will perform a series of similar balletic maneuvers according to the following timetable:

Earth flyby: 13 April 2020
First Venus flyby: 16 October 2020
Second Venus flyby: 11 August 2021
First Mercury flyby: 2 October 2021
Second Mercury flyby: 23 June 2022
Third Mercury flyby: 20 June 2023
Fourth Mercury flyby: 5 September 2024
Fifth Mercury flyby: 2 December 2024
Sixth Mercury flyby: 9 January 2025
Arrival at Mercury: 5 December 2025

Wow — that’s more than 6 years which includes one Earth flyby, two of Venus and six passes of Mercury. More energy is required to get to Mercury than the the recent New Horizons mission to Pluto!

This photo of Mercury was taken by NASA’s orbiting MESSENGER space probe. The prominent rayed crater at center right is Debussy, named for French composer Claude Debussy. The planet resembles a lunar landscape at first glance, but Mercury has its own unique features including a magnetic field and tons of water ice inside shadowed craters at its poles. It also used to be bigger but shrunk, leaving huge wrinkles of rock on its surface called scarps. With no atmosphere, surface temperatures there range from 800°F (425°C) during the day to –290°F (–180°C) on the night side. NASA

The odd-sounding mission name honors the Italian mathematician and engineer Giuseppe ‘Bepi’ Colombo who passed away in 1984. Colombo proposed a successful flyby technique for NASA’s Mariner 10 mission in 1974-75. When the ship arrives at Mercury in late 2025, it will endure temperatures in excess of 660°F (350°C) and gather data including photos during its 1-year mission with a possible 1-year extension. The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). 

We’ll have a chance to glimpse Mercury in early November with a little help from the moon. Stellarium

Scientists hope to learn more about the planet’s origin and evolution, its magnetic field,  geology — surface and interior — and composition with the many instruments on board the spacecraft. I always like to see the objects of scientific study first hand, but Mercury is currently too low in the evening sky and lost in the solar glare. However, the view improves a little next month. With a wide-open horizon and a little help from the thin moon we might spy the planet about 20 minutes after sunset a few degrees high and 6° below the crescent.

Enjoy the launch!

6 Responses

  1. Troy

    I wonder if the Earth flyby in 2020 will be visible? Maybe even a flash off the solar panels.
    It sounds like an interesting mission, but sadly the lander has been cancelled. That would have delivered an historic view of a new horizon.

    1. astrobob

      Hi Troy,

      I didn’t check distance but the satellite group is always keen on trying to see these flybys. Usually requires a telescope as you can imagine.

      1. Troy

        Bob, I was thinking it might be something like what was known as the “NEAR flash”. NEAR was the probe that orbited the asteroid Eros. On the way to the belt it flew by Earth and supposedly was supposed to flash the Earth as it flew by and the large solar array reflected sunlight back to the night side of Earth. It was in January so weather was of course terrible, so regrettably I saw nothing but still hope for an encore.

        Not sure if you allow links but I found one of the event. I don’t think anyone say it actually…

        https://www.sciencemag.org/news/1998/01/near-spacecraft-flash-earth

        1. astrobob

          Hi Troy,
          The link is fine especially coming from you. I see what you mean. I’ve also heard of spacecraft being close enough to view as one might a faint asteroid. Thanks!

          1. Richard Keen

            Hi Bob and Troy,
            I was lucky enough to view Rosetta during its first Earth fly-by in 2005. Here’s a link to an observation I posted on Seesat:
            http://www.satobs.org/seesat/Mar-2005/0046.html
            If you browse their archives you’ll find other flyby observations.
            Rosetta was 0.0015 AU distant at the time, or about half as distant as the moon.

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