The European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) have successfully launched BepiColombo, their joint mission to Mercury. The spacecraft successfully blasted off a few days ago from the Kourou Spaceport in French Guiana.
BepiColombo is comprised of two orbiters. JAXA designed the Mercury Magnetospheric Orbiter while ESA built the Mercury Planetary Orbiter. The goal of the joint mission is to take a variety of complementary measurements of the planet to reveal its internal structure, how it interacts with the solar wind, and new details about its surface and evolution.
"Launching BepiColombo is a huge milestone for ESA and JAXA, and there will be many great successes to come," Jan Wörner, ESA Director General, said in a statement. "Beyond completing the challenging journey, this mission will return a huge bounty of science. It is thanks to the international collaboration and the decades of efforts and expertise of everyone involved in the design and building of this incredible machine, that we are now on our way to investigating planet Mercury's mysteries."
The journey to Mercury won’t be a straightforward one. The spacecraft will perform several gravity assist flybys in combination with solar electric propulsion to get into Mercury’s orbit. It will pass by our planet again in April 2020, and then do two flybys of Venus and six of Mercury before it is captured by the gravity of the smallest planet in late 2025.
"BepiColombo is one of the most complex interplanetary missions we have ever flown," added Andrea Accomazzo, ESA Flight Director for BepiColombo. "One of the biggest challenges is the Sun's enormous gravity, which makes it difficult to place a spacecraft into a stable orbit around Mercury. We have to constantly brake to ensure a controlled fall towards the Sun, with the ion thrusters providing the low thrust needed over long durations of the cruise phase."
This seven-year journey might be long but it won’t be idle. Both orbiters will use their instruments as they travel past Venus, collecting precious information about the planet and its thick atmosphere. The mission is not just versatile in its data collection, it’s also as sturdy as it can be.
BepiColombo will experience temperature changes from -180 to 450°C (-292 to 842 °F). The JAXA orbiter will spin every four seconds to avoid overheating, while the ESA one has a wide radiator to keep it cool. The two spacecraft will be placed on different orbits, which should deliver a unique understanding of the planet. The teams hope to discover how Mercury formed so close to the Sun and this could be applied to exoplanets as well.