Mercury spacecraft BepiColombo sends first images of Mercury

Nearly three years after its launch, the European-Japanese space probe BepiColombo has captured its first images of the planet Mercury. As the European Space Agency ESA announced on Saturday, the probe transmitted black-and-white images to Earth after its first flyby of Mercury, showing the planet's northern hemisphere. With its large craters, Mercury's surface is reminiscent of the moon.

BepiColombo captured this view of Mercury on Oct. 1, 2021, as the spacecraft flew past the planet for a gravity assist maneuver (ESA/BepiColombo/MTM)

The spacecraft reportedly flew past Mercury at an altitude of 199 kilometers. However, because BepiColombo arrived on the night side of the planet, conditions were "not ideal" for taking images at close range, ESA explained. Therefore, the next image was taken from a distance of about a thousand kilometers.

BepiColombo had launched Oct. 20, 2018, on a seven-year journey to the smallest and least explored planet in our solar system. Named after Italian mathematician and engineer Giuseppe "Bepi" Colombo and led by ESA, the mission to the planet closest to the sun is considered Europe's most complicated space project to date.

The challenge of the sun's gravitational pull

The journey is complicated primarily by Mercury's proximity to the sun. Given the sun's enormous gravitational pull, it takes a lot of energy to slow down a spacecraft so that it can enter an orbit around the solar system's innermost planet.
In the case of BepiColombo, this means: To adjust its speed, the probe must complete a total of nine planetary flybys. It has already flown close to Earth once and Venus twice. After a total of six flybys of Mercury, the probe is scheduled to enter orbit around its target planet in 2025.

So far, only two missions from the U.S. space agency NASA have reached Mercury: "Mariner 10" in the 1970s and the "Messenger" space probe, which orbited Mercury from 2011 to 2015. The BepiColombo mission will explore the peculiarities of Mercury's internal structure and its magnetic field and, among other things, investigate the question of whether there is ice in the craters facing away from the sun.

Strong Austrian participation

The joint European-Japanese project is characterized by a strong Austrian participation: For example, the Institute of Space Research (IWF) of the Austrian Academy of Sciences is responsible for the magnetic field instruments of both space probes. Both magnetometers (MPO-MAG and MMO-MGF) are switched on continuously. From MPO-MAG, whose sensor is located at the already unfolded boom, the results are awaited with high excitement. "For the first time, a spacecraft will measure the Mercury magnetic field of the Southern Hemisphere at low altitude," as noted by Wolfgang Baumjohann of the IMF, who is the scientific director of MMO-MGF. This would put the previously established models for the planet's intrinsic magnetic field to the test. The PICAM ion spectrometer will also be turned on during the Mercury flyby to search for different types of ions in Mercury's extremely thin atmosphere for the first time. IMF's participation in BepiColombo was funded by the Austrian Federal Ministry for Climate Protection, Environment, Energy, Mobility, Innovation and Technology (BMK) through the Austrian Research Promotion Agency (FFG).

Control technology from Vienna

Technology from Vienna controls the Mercury probe: the guidance system comes from Austrian space company RUAG Space Austria in the federal capital, where it was also developed and built, the company emphasized. In addition, the space supplier also supplied the motor control system for the alignment of the solar panels. Furthermore, the Viennese experts protected the probe from the extreme temperatures in space: "Mercury is the closest planet to the sun, so the probe has to withstand extreme heat of over 450 degrees Celsius," as CEO Andreas Buhl clarified. The high-temperature insulation with ceramic fibers also serves as protection against micrometeorites.
According to the company, every European satellite is protected with thermal insulation from RUAG Space. About 1,300 employees in six countries develop and produce products for satellites and launch vehicles, according to the company. RUAG Space is part of the international technology company RUAG international, based in Switzerland.