The flight past Venus provides an opportunity to test equipment aboard the BepiColombo spacecraft before it approaches its first target, Mercury.
En route to Mercury, the BepiColombo spacecraft from Europe and Japan flew past Venus on August 10, sending back numerous images and measurement results that could reveal new information about the planet’s atmosphere. The European Space Agency (ESA), in collaboration with the Japan Aerospace Exploration Agency (JAXA), released the first image taken while flying past Venus shortly after BepiColombo made its closest approach to the planet on the evening of August 10. During this encounter, the spacecraft flew within 552 kilometers of Venus’s surface. ESA stated that the spacecraft will send back more images in the near future.
The BepiColombo spacecraft captures an image with Venus during its close flyby on August 10. (Image: ESA)
The first “selfie” with Venus was taken at 8:57 PM Hanoi time on August 10, when BepiColombo was 1,573 kilometers away from Venus. Three cameras provided several black-and-white images with a resolution of 1024 x 1024 pixels, originally intended to monitor the deployment of BepiColombo’s solar panels after its launch in October 2018. Since then, the research team behind the BepiColombo project has found creative ways to utilize the cameras during the spacecraft’s nine flybys of Venus on its way to its target.
In April 2020, BepiColombo captured images of Earth during its last flyby of the planet from a distance of 12,689 kilometers. In October 2020, the spacecraft made its first observation of Venus while flying past at a distance of 10,700 kilometers.
The next opportunity for BepiColombo to capture images will be on October 1 (less than two months away). This will be the first time the spacecraft, named after the Italian physicist Giuseppe (Bepi) Colombo, will observe Mercury. In total, BepiColombo will fly by the smallest planet and the one closest to the Sun six times before entering its designated orbit in 2025. Each flyby is designed to adjust BepiColombo’s trajectory, helping the spacecraft slow down under the Sun’s gravitational pull to approach Mercury correctly.
“Venus is a very bright planet, and those selfie cameras were not designed to observe similarly bright objects from such a close distance,” explained Johannes Benkhoff, a scientist working on the BepiColombo project at ESA, regarding the overexposed image of Venus.
However, BepiColombo is also equipped with a floating imaging camera that cannot be used when flying through the inner solar system. In fact, BepiColombo consists of three stacked spacecraft, meaning some equipment is obscured. The spacecraft carries two other vehicles, including the European Mercury Orbiter and the Japanese Mercury Atmospheric Orbiter, located at the top of the transfer module. With a solar panel spanning 15 meters, the transfer module is responsible for delivering the two orbiters to Venus and will be discarded after the trio reaches their destination. Only when they separate and enter their respective orbits can the two spacecraft fully utilize their equipment.
Even in its moving configuration, some instruments have collected useful data during the flybys. The most recent flyby of Venus could provide particularly interesting information about the chemical composition of the planet’s atmosphere. Next, the spacecraft will fly past Mercury at a distance of just 200 kilometers from the planet’s surface. The October flyby will mark the first time a spacecraft visits the scorching rocky planet closest to the Sun since NASA’s Messenger mission ended in 2015. The BepiColombo research team hopes to uncover some of the planet’s mysteries, such as whether it has water ice in its polar craters.
