Europe’s Mercury test BepiColombo will investigate its objective planet on Monday (June 19), and we can anticipate that a few energizing new pictures should arrive at Earth not long after that.
At 3:34 p.m. EDT (1934 GMT), the flyby, BepiColombo’s third of Mercury, will see the spacecraft fly by the planet at a superclose distance of just 147 miles (236 kilometers). That’s closer than the two orbiters of the probe will get in the course of the main mission.
However, the primary objective of the flyby is not to capture stunning close-up images of Mercury’s surface but rather to use Mercury’s gravity to slow the probe down so that it can enter the planet’s orbit in late 2025.
“Due to the fact that it launched from Earth and is orbiting the sun like our planet, our spacecraft started with far too much energy. “We’re using the gravity of Earth, Venus, and Mercury to slow down,” ESA flight dynamics expert Frank Budnik said in a statement. “We need to be captured by Mercury to do that.”
The BepiColombo mission, which is a joint venture between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), is only the third spacecraft in history to examine Mercury, the innermost planet in the solar system and one of the most notoriously challenging planets to study.
Even though Mercury is on average 10 times closer to Earth than Jupiter, reaching the innermost planet takes the same amount of time as reaching the gas giant. This is because a spacecraft headed for Mercury must constantly brake against the sun’s strong gravitational pull. To do that BepiColombo, which sent off in 2018, is making painstakingly determined flybys of planets along its way while in circle of the sun. Mercury has been passed by the spacecraft twice before, in October 2021 and July 2022. The spacecraft had also been to Venus twice and Earth once before that.
“BepiColombo will be traveling in relation to Mercury at 3.6 km/s, or 2.2 miles per second, when it begins to feel the planet’s gravitational pull. Budnik stated, “That’s just over half the speed at which it approached during the previous two Mercury flybys.”
Budnik went on to say that the flyby will also change the spacecraft’s direction by 2.6 degrees and reduce its velocity by 0.5 miles per second (0.8 kilometers per second) in comparison to the sun.
BepiColombo will have to make three more flybys of Mercury before it gets slow enough to be captured by the rocky planet, which is only slightly larger than Earth’s moon: in September 2024, December of the same year, and January of 2025.
Scientists are excited to use the opportunity to measure Mercury’s boiling environment because some of the spacecraft’s instruments will be operational during the journey. During the flyby, three low-resolution monitoring cameras aboard BepiColombo will be busy taking black-and-white images of the unexplored rocky world.
Johannes Benkhoff, the BepiColombo project scientist at ESA, stated in the statement that the previous two Mercury flybys had already produced intriguing scientific findings. For instance, the probe discovered the charge composition of the planet’s weak southern inner magnetosphere by taking the first ever measurements there.
Benkhoff stated, “Collecting data during flybys is extremely valuable for the science teams to check the operation of their instruments prior to the main mission.” Additionally, it presents a novel opportunity to compare the data gathered by NASA’s MESSENGER spacecraft during its 2011–2015 Mercury mission with data gathered from complementary locations on the planet that are typically inaccessible from orbit.”
The BepiColombo spacecraft is made up of two orbiters that are currently stacking one on top of the other and traveling through the solar system. Because of this, some of the instruments on the probes are covered up during the cruise. However, the first data will be collected by two instruments designed to examine Mercury’s gravitational field and measure the surface’s shape during the Monday flyby. Unfortunately, the primary high-resolution cameras of the orbiters will not yet be available.
Mercury has previously been closely studied by two probes. In 1974 and 1975, NASA’s Mariner 10 flew by Mercury three times, taking the first images of the smoldering planet. From 2011 to 2015, the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) mission of NASA was in orbit around the planet.