The joint European/Japanese (ESA/JAXA) BepiColombo mission to Mercury lifted off at 9:45 p.m., EDT Oct 19, from Kourou, French Guiana. After a 7 year journey, the mission will deploy two science orbiters, one European and one Japanese, around Mercury. The launch video can be seen at livestream.com/....
The spacecraft will take 7 years to reach its science orbit around Mercury, in Dec 2025. To get to Mercury without being subsumed by the Sun, the spacecraft will make a series of nine planetary flybys, circling Earth once, Venus twice, and Mercury itself six times. Reaching Mercury requires slowing down the spacecraft considerably, since the spacecraft speeds up as it gets closer to the Sun and would require a massive amount of fuel to make the maneuvers. Instead, a number of flybys around planets are used slow down the spacecraft. Electrical propulsion is used to make small corrections; chemical thrusters are used for final capture and orbit insertion. See issfd.org/...for technical details of the trajectory.
The mission will deploy two science orbiters, one European and one Japanese, to make complementary measurements of the planet's dynamic environment at the same time. There are no rovers or landers on this mission. The Mercury Planetary Orbiter will study the surface and internal composition of the planet, and the Mercury Magnetospheric Orbiter will study Mercury's magnetosphere, that is the region of space around the planet that is dominated by its magnetic field.
See sci.esa.int/… and en.wikipedia.org/… for more details.
BepiColombo will be the third mission to visit the planet Mercury. NASA's Mariner 10, flew past Mercury three times in 1974-5 and returned the first close-up images of the planet. NASA's MESSENGER spacecraft orbited and studied Mercury during 2011-2015. MESSENGER used a similar trajectory as BepiColombo, arriving at Mercury 7 years after launch. It de-orbited as planned and crashed on the surface of Mercury on April 30, 2015
Here is a multi-color image of Mercury, based on spectral images collected by MESSENGER. The colors depict physical and chemical differences on the surface, including mineralogical diversity and the exposure age of the craters.
Why isn’t NASA a partner in this mission? Does anyone know the answer?
Here is the launch video -