The European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) initiated a mission to explore Mercury — the planet closest to the Sun — this past Saturday.
The initiative, named the BepiColombo mission, began successfully when an Ariane 5 rocket launched from Europe’s spaceport in French Guiana at 1:45:28 GMT. Signals from the spacecraft were received at ESA’s control station in Darmstadt, Germany at 02:21 GMT, confirming the success of the launch. The journey will take seven years to complete.
The mission involves a science orbiter from each of the involved space agencies; ESA’s Mercury Planetary Orbiter (MPO) and JAXA’s Mercury Magnetospheric Orbiter (MMO). They will be delivered to their destination via the Mercury Transfer Module (MTM) built by ESA. This spacecraft will use a combination of solar electric propulsion and gravity assist (movement or maneuver with the help of gravity from a nearby planet or other astronomical object) flybys to complete the 77 million kilometer journey. In layperson’s terms, this means that the spacecraft will use the gravity of other planets to slow down, lest they approach Mercury too fast and are hijacked by the Sun’s gravity in the process.
The two probes have distinct roles. The MMO will remain focused on studying the planet’s magnetic field and its interaction with ‘solar waves’ from the sun. Meanwhile, the MPO will study the planet’s terrain.
Director General ESA Jan Wörner has termed the BepiColombo a milestone for both ESA and JAXA, adding that there would be many more such successes in the future.
JAXA President Hiroshi Yamakawa expressed gratitude for the success of the launch, and has said that he hopes this mission will give insights into the origin of the solar system.
Mercury offers many mysteries scientists hope to solve. One of these is the planet’s oversized iron core, which makes up 60 percent of Mercury’s mass. So far scientists have not been able to explain why the planet has such a thin crust compared to other planets. Because of this composition, some scientists also theorize that Mercury was not part of our solar system initially, and was sucked into it by the Sun’s gravity at a later point in time.
The mission does not come without its challenges. Apart from the huge distance, complications could also arise because of Mercury’s close proximity to the Sun. Gravity from the star makes it difficult for spacecrafts to find stable orbit around Mercury. The spacecrafts will also endure temperatures ranging from 180ºC to 450ºC.
This is the first time the European and Japanese space agencies have sent a mission to Mercury. Prior to this, NASA had sent missions to the iron planet in 1973 and 2004.