ESA's Plato Exoplanet Mission Enters Thermal Vacuum Testing

Europe's hunt for Earth-like exoplanets is heating up — literally.

The European Space Agency's Plato spacecraft is now sealed inside the Large Space Simulator at ESA's Test Centre, undergoing a series of space-like thermal vacuum tests. Engineers placed the satellite in the LSS chamber on February 18, and since early March it's been experiencing the extreme temperatures and vacuum of space.

The photo, taken from the top opening of the simulator, shows Plato's 26 ultrasensitive cameras mounted on a five-stepped platform — the spacecraft's special eyes that will monitor more than 150,000 bright stars simultaneously, hunting for terrestrial planets orbiting Sun-like stars.

The test conditions are brutal: the spacecraft's backside reaches 160°C when exposed to heating elements that simulate solar radiation, while the cameras and optical bench are kept at around –80°C, mimicking deep space. The LSS achieves pressure a billion times lower than sea-level atmosphere.

Plato will emerge from the simulator at the end of March. The mission is expected to be ready for launch by end of 2026, with liftoff on an Ariane 6 planned for January 2027, according to ESA.