The European Space Agency is preparing for back-to-back flybys of the same planet by two different spacecraft just one day apart.
On 9 August, the Esa-Nasa Solar Orbiter spacecraft will fly past Venus with a closest approach of 7,995km (4,968 miles). A day later, the Esa-Jaxa BepiColombo mission will make its pass at an altitude of just 550km (342 miles).
Flying close to a planet is known as a gravitational assist. This is because such flybys were first used to increase the orbital energy of a spacecraft, slingshotting it further into the solar system.
But here, both missions will use the manoeuvre to lose energy, allowing them to fall closer to the sun. In the case of Solar Orbiter, the gravity of Venus will help alter its orbital inclination, eventually allowing the spacecraft to see the poles of the sun.
BepiColombo’s ultimate destination is the planet Mercury, the closest planet to the sun. Using gravitational assists from Earth, Venus and Mercury, Bepi will execute the delicate manoeuvre of dropping into orbit around the tiny planet, a difficult task considering Mercury is deep in the Sun’s mighty gravitational field. Data collected during the flybys will be combined with Jaxa’s Akatsuki mission, which is currently in orbit around Venus.
