Are there planets other than Earth suitable for life in the Universe? Since the discovery of the first exoplanet 30 years ago, nearly 5,700 planets have been identified outside our solar system, and the list continues to grow. But none, until now, meets all the essential conditions for life. With its cameras, the Plato satellite (for PLAnetary Transits ans Oscillations of stars), developed by the European Space Agency, has the mission of finding these new… habitable Earths. The satellite is currently under construction.
Before entering the huge clean room, the room where the satellite is assembled and tested, it is essential to equip yourself: “ Dust should not be brought inside. warns Catherine Vogel, head of the Plato program at manufacturer Thales Alenia space. Therefore all personnel who work in the clean room must be equipped with a cap, a beard cover, a blouse and overshoes. »
We must prevent the slightest grain of dust from blocking the complex machinery of the satellite. “ You should know that this satellite leaves five times the Earth-Moon distance and it must be entirely autonomous,” continues the project manager.
For the moment, piles of cables and computer equipment are escaping from a module being assembled. Soon, 26 high-precision cameras will be added. Once in space, they will have around 200,000 stars in their viewfinder for 2 years straight. “ A technological challenge is to be able to point at the stars without moving, with a precision that would be the same as holding a grain of sand in the hand, aiming at this grain of sand with a laser from a distance of a kilometer », explains Catherine Vogel.
All under enormous temperature constraints which must not disturb the instruments. “ When the specimen is in the air, suddenly it will be heated by the sun. Suddenly, it will be hidden. So as a result, you will have hot and cold effects all the time, between -94 degrees and +163 degrees,” detailed Sébastien Guerrere, responsible for the solar generator.
In front of a huge capsule, the latter tests the thermal shield which will protect the satellite: “ When we close the big lid, we will create a vacuum and we will be able to raise the enclosure to very high or very low temperatures, in conditions which are close to what we will see in space. »
Also readEurope refines its strategy to find its way back to space
“OWe are really looking to find planets that are similar to Earth.
Once in orbit, Plato must be able to spot the tiny shadows of the planets when they pass in front of their sun and carry out a whole series of measurements to say whether they can potentially be habitable, summarizes Catherine Vogel. “ Life elsewhere means planets that are in areas where there is potentially water. So you shouldn’t be too close to your sun because otherwise all the water will evaporate and you’ll burn. You don’t have to be too far away because otherwise everything freezes, describes the project manager. So we’re really looking to find planets that are similar to Earth. Today we are at the beginning of a great era of discoveries. I think we’re all trying to figure out if we’re the only ones, and the likelihood that we are the only one gets smaller and smaller as we discover more. »
The satellite must be launched at the end of 2026, with, she hopes, the first findings in 2027.
To listen in Around the questionHow far will the James Webb Space Telescope take us?