The European Space Agency’s mission Plato is set to launch at the beginning of 2027 on a quest to find Earth-like planets orbiting stars similar to our Sun. The spacecraft will board the Ariane 6 with two boosters for a launch from Europe’s Spaceport, in French Guiana.
After lift-off, Plato will travel towards the Sun-Earth Lagrange point L2. This animation shows Plato’s first moments in space and its trajectory towards L2. This is an equilibrium point of the Sun-Earth system that revolves around the Sun together with Earth. It is located 1.5 million kilometres from Earth in the direction opposite the Sun.
The spacecraft will approach this point after a one-month journey and then enter a large-amplitude orbit around it.
To hunt for exoplanets, Plato is equipped with 26 ultrasensitive cameras. They are specially designed to capture the tiniest variations in the intensity of a star’s light and thus spot the dimming effect caused by planets passing in front of their host stars.
The mission’s focus is to discover planets that circle Sun-like stars in the habitable zone – the ‘Goldilocks’ region, where the temperature is just right for liquid water to exist on a planet’s surface. These planets take several months to complete an orbit because of their distance from the host star: not too close, not too far. To spot them, Plato’s 26 eyes will stare at the same region of the sky continuously for a minimum of two years, during a mission that is planned to last at least 4 years.[AK1]
During these long observations, the spacecraft must be periodically reoriented to ensure that the solar arrays are pointed towards the Sun. This is achieved by rotating the spacecraft by 90° roughly every 3 months, as shown in the animation.
At L2, Plato will join other space missions orbiting around this special point such as the ESA Euclid mission and the NASA/ESA/CSA James Webb Space Telescope.