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.
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!
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).
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!