PLANETARY EXPLORATION
▼ Inner world: BepiColombo is travelling to Mercury, the closest planet to the Sun
NASA’s Lucy probe, set to launch in October, will embark on a voyage to study a curious group of Jupiter-trailing asteroids, known as ‘Trojans’. Examining these gravitationally trapped leftovers from the birth of our Solar System might yield clues not only about their origins, but also about our own.
A close look at the Sun
Two months before Lucy launches, Solar Orbiter will hurtle past Venus and, in November 2021, it will also pass Earth as part of its decade-long odyssey to get up close and personal with our parent star. The probe and its heavy-duty heat shield will perform several Venus ‘gravity-assists’ to creep to within
60 solar radii, a third of the distance between Earth and the Sun. It promises Solar Orbiter a splendid (though blisteringly hot and extremely risky) ringside perspective of our star’s majestic fury. Working in tandem with the 2018-launched Parker Solar Probe, it will investigate energetic plasmas, the mysterious heating mechanism behind the glowing corona and the nature of the solar wind.
Indeed, Venus will be a busy stopping-off place for spacecraft in 2021. Not only will Solar Orbiter pay it a visit, but so too will the ESA/JAXA mission BepiColombo. While the Solar Orbiter will return to Venus time and again, BepiColombo will do so once; the fleeting encounter will reshape the spacecraft’s orbit to reach its own destination under optimum conditions. And that destination is not Venus or the Sun, but the Solar System’s innermost planet, sparsely-explored Mercury. In October 2021, BepiColombo will perform the first of six flybys of Mercury, before entering orbit around this diminutive world. That same month, Russia’s Luna 25 mission will also launch, bound for Boguslavsky Crater, near the Moon’s south pole, with Astrobotic’s Peregrine lunar lander also due to fly atop the first Vulcan Centaur rocket.
As these missions begin, others will inexorably approach their end. OSIRIS-REx, which in October 2020 triumphantly touched the surface of asteroid Bennu, some 321 million kilometres away, and captured soil specimens with its touch-and-go sampling head, will begin its 30-month trek back to Earth in March 2021. And the curtain will also descend on the long-serving Juno spacecraft, which has for five years unveiled the internal dynamics of Jupiter in unrivalled detail and returned astonishing views of its colourful clouds from polar orbit. Juno will breathe its last in July 2021, with a destructive dive into the atmosphere of the Solar System’s largest planet.