BepiColombo spacecraft launched at Mercury

The space probe BepiColombo at the European Space Agency (ESA) in Dutch Noordwijk 2017. She is now on the way to Mercury. (Photo: Michael Kooren / Reuters =

(DPA / SDA) The ambitious Euro-Japanese space mission to Mercury began: a European launcher Ariane 5 was launched on Saturday at 3:35 am (CEST) with the space probe BepiColombo aboard the space station Kourou in French Guiana. Both at the spaceport and in the Darmstadt control center (ESOC), the beginning of the mission was followed with great interest.

But the journey of the 6.4-meter and 4.1-tonne spacecraft is just beginning. According to calculations by the European Space Agency Esa, the probe will reach Mercury with its two satellites in December 2025. Until then, researchers will have to intervene several times from Earth. Over the next few days, approximately 80 specialists will oversee the mission at the Darmstadt Control Center (ESOC). Johann-Dietrich Wörner, CEO of Esa, estimated the total cost of the mission, development and operation, at around two billion euros. Of these, Esa carries 1.5 billion euros.

The tension will rise again in mid-December. Then, for the first time, the ionic motors of the probe will be used. If they do not work, the mission could fail. The spacecraft must cross the planets nine times – once Earth, twice Venus and six times Mercury – especially to slow down. "We have to be careful not to fly in the sun, which means we have to slow down all the time," said Esa Wörner's CEO. Each flyby of a planet requires intense preparation.

The eponym of the mission is the Italian mathematician Bepi Colombo (1920-1984), who had calculated the basis of a trajectory towards Mercury. If the mission goes as planned, two satellites separate from the probe at the target and explore Mercury in different orbits. The Esa MPO (Mercury Planetary Orbiter) satellite, also called "Bepi", will study the surface. The Japanese MMO (Mercury Magnetospheric Orbiter) satellite – or "Mio" – is targeting the planet's magnetic field. It is said that it crash after about 3.5 years of using the Mercury.

Swiss technology on board

There are eleven cameras and instruments aboard the European satellite. Swiss technology is also part of the project. One of the instruments on board the Esa orbiter is a laser altimeter called Bela (BepiColombo laser altimeter), designed to create a 3D image of the Mercury surface. The instrument was designed and built at the University of Bern. Mercury's mission is not the only one to reach the world of Swiss university research: for example, the company Ruag Space has supplied several components and the obiter structure in aluminum panels. Micro-Cameras & Space Exploration SA has also produced camera systems for BepiColombo.

Four research institutions are involved in four instruments. These include the Mertis infrared spectrometer from Münster. He should explore the surface of Mercury and help understand the origin of our solar system. At least a year is devoted to research, but Bepi could work for four years. Then the device is supposed to burn, so that Esa.

Extreme temperature differences

Until now, only two US probes have explored the planet closest to the Sun: "Mariner 10" in the 1970s and the probe "Messenger", which came into orbit around the planet in 2011. The surface Rocky Mercury is, like that of our moon, full of craters. The temperature differences on the planet are extreme. During the day, more than 400 degrees are reached, at night it is cold until minus 180 degrees.