This past week, the European Space Agency (ESA) completed the critical milestone review for Plato, a mission to investigate far-off habitable planets, giving it the green light to continue development.
Plato, or PLAnetary Transits and Oscillations of stars, is a telescope that will use 26 cameras to discover and characterise extrasolar planetary systems, focusing particularly on terrestrial planets in the habitable zone around stars like our Sun. According to ESA’s website, the mission’s goal is to answer the question: “how common are worlds like ours and are they suitable for the development of life?”
The launch is currently planned for late 2026. Plato will travel to Lagrange point 2 in space, almost one million miles from Earth, after which it will observe more than 200,000 stars during its four-year nominal operation.
By detecting regular dips in a star’s light caused by the transit of a planet across the star’s disc, the telescope will be able to precisely determine the properties of exoplanets and their host stars. It has also been designed to investigate seismic activity in the stars, and thereby their age.
“The mission will serve the science community to gather invaluable knowledge of planets in our galaxy, beyond our own solar system,” said Filippo Marliani, project manager of Plato at ESA. “The successful completion of the critical milestone and the formal start of the second phase of this extraordinary mission constitutes an important boost of positive energy for the next challenges to be tackled with our industrial, institutional and academic partners.”
The review, which was carried out between July and December, verified the maturity of the spacecraft platform and payload module, confirming the payload schedule with a particular focus on the production of the 26 cameras. Review teams consisting of more than 100 people submitted their findings to the board, which concluded its review on January 11.
Now, the second phase of the industrial contract can start. The next major milestone for Plato is the spacecraft critical design review in 2023, which will verify the detailed design of the complete spacecraft before proceeding with its assembly.
Nearly all aspects of the cameras production, assembly, and testing have been exercised successfully with the tests of structural, engineering and qualification models of the camera units at several European facilities.
“After this successful review we can continue the implementation of this exciting mission that will revolutionise our knowledge of exoplanets down to Earth-size and open new venues in the study of the evolution of stars,” said Ana Heras, project scientist of Plato at ESA.
Plato is the third medium-class mission in ESA’s Cosmic Vision program, which seeks to answer fundamental questions about our universe. It is preceded by Solar Orbiter, a spacecraft that ventured closer to the Sun than almost any other in 2020, and Euclid, a space telescope scheduled for launch in 2023 that will map out the large-scale structure of the Universe across 10 billion light years to understand the history of its expansion and the growth of structure during the last three-quarters of its history.