Europe’s next major space mission, a telescope that will search for rocky, Earth-like planets outside our solar system, will launch in late 2026. PLATO, or PLAnetary Transits and Oscillations of stars, is being developed to spot potentially habitable worlds around Sun-like stars. The space telescope will be launched into orbit aboard Europe’s new Ariane-6 rocket, which made its maiden flight last week after being developed at a cost of €4bn (£3.4bn).
Dr David Brown, from the University of Warwick, will give an update on the mission at the Royal Astronomical Society’s National Astronomy Meeting, being held at the University of Hull this week. “PLATO’s aim is to search for exoplanets around stars similar to the Sun and with orbital periods long enough to fall within the habitable zone,” he said. “One of the mission’s main goals is to find another Earth-Sun equivalent pair, but it is also designed to carefully and precisely characterise the exoplanets it finds (for example, calculating their masses, radii and bulk densities).”
PLATO isn’t just an exoplanet hunter, though. It’s also a stellar science mission. In addition to searching for exoplanets, it will study stars using a variety of techniques, including asteroseismology (measuring the vibrations and wobbles of stars), to determine their masses, radii, and ages.
Unlike most space telescopes, PLATO has multiple cameras, including one called Arthur Eddington, named after the famous astronomer and physicist who won the prestigious Royal Astronomical Society Gold Medal in 1924. It has 24 ‘Normal’ cameras (N-CAMs) and 2 ‘Fast’ cameras (F-CAMs). The N-CAMs are arranged in four groups of six cameras, with the cameras in each group pointing in the same direction but the groups slightly offset. This gives PLATO a very wide field of view, improved science performance, redundancy against failures and a built-in way to identify ‘false positive’ signals that could mimic the transit of an exoplanet, Dr Brown explained.
“The planned observing strategy is to observe two patches of sky, one to the north and one to the south, for two years each,” he added. “The south-facing patch has already been chosen, while the north-facing patch will not be confirmed for a few years.” Several components of the spacecraft have finished their production schedules and are close to completing calibration tests.
These include the UK-supplied Front-End Electronics (FEE) for the N-CAM. Built by the Mullard Space Science Laboratory at University College London, these operate the cameras, digitise the images and pass them on to the onboard data processing. Ten of the final cameras have been built and tested, with the first of these being mounted on the optical bench, the surface that keeps all the cameras pointed in the right direction, earlier this year. The mission is due to launch in December 2026.