Europe will hunt for Earth-like planets. The Plato ESA mission has in fact passed a ‘crucial’ test and received the green light to complete the satellite and payload construction process. Italy also participates in the challenge under the coordination of the Italian Space Agency and thanks to the commitment of teams of national scientists and industries. Plato – the Planetary Transits and Oscillations of stars mission – is the third middle class of ESA’s Cosmic Vision program and its The aim is to find and study extrasolar planetary systems, focusing, in particular, on the properties of terrestrial planets in the habitable zone around sun-like stars. The Plato mission was also designed to study seismic activity in stars allowing for precise characterization of the planet’s host star, including its age.
Asi and Inaf announced that a commission appointed by the European Space Agency subjected the Plato e verified the maturity of the satellite and the on-board instruments, thus confirming the feasibility of the program construction of the satellite and the solidity of the Payload production plan in which there is also the contribution of Italy. This step involves the mass production of 26 sophisticated telescopes – called Plato Camera – with which Plato will discover and study the characteristics of exoplanets, even very similar to Earth, and which orbit stars similar to the Sun. The Italian Space Agency and the National Institute of Astrophysics underline that this exam, called Critical Milestone Review, was requested by ESA due to the development complexity associated with the mass production of telescopes.
The review was carried out between July and December 2021 by a team of more than 100 ESA scientists and engineers divided into two commissions, one for the Satellite and one for the Payload. All aspects of the production, assembly and testing of the telescopes have been successfully verified through telescopes tests carried out in various European industries and research institutes. The properties of very high stability with the temperature of the optical bench that houses the telescopes – Plato will operate at approximately -90 ° C – were verified with a new test technique developed by the satellite’s main contractor, Ohb System Ag. I results were presented to the review committee on 11 January 2022 which decreed the achievement of the expected results.
Having reached this milestone, now the second phase of the industrial contract led by Ohb System Ag can begin as prime contractor with Thales in France and Ruag Space System Switzerland as part of the Core Team. “The telescope development team, led by INAF, has coordinated the activities in these two hectic years with great effectiveness despite the pandemic making it almost impossible to visit the laboratories of international partners” says with satisfaction Luca Valenziano of INAF, Project Manager of the Plato Camera. “The intermediate milestone reached with this Milestone makes us proud and confident for the demanding phase of construction of the instruments that will see Italian researchers in the front row in almost every area of this complex, ambitious mission “he comments again.
The supply of Plato’s Payload is the responsibility of the European Space Agency in collaboration with a European consortium of institutes and industry, the Plato Mission Consortium, in accordance with the multilateral agreement established with ESA. The Italian contribution to the Payload is important and articulated. Under the coordination of the Italian Space Agency – which finances the industrial activities for the realization of the parts of Italian responsibility for the mission and provides support to the scientific team – and the supervision of Inaf researchers – creators of the optical project – the opto-mechanical structures of the telescopes are built and subjected to stringent tests to verify performance in Leonardo’s Florentine factories, in collaboration with Thales Alenia Space Italia and the SMEs Medialario, Hst and Silo.
Always under the coordination of ASI, and the supervision of INAF researchers, who also create the software, the on-board computer that serves the Payload is built in the Livorno factories by Kayser
Italy. Finally, a team of Inaf researchers and engineers coordinates the development and verification activities of all the telescopes conducted at industries and research institutes in the European countries that belong to the Plato Mission Consortium. Mario Salatti, Program manager of Asi for the development of the optical part of the telescopes, speaks of Plato defining it “an extraordinary mission” because “it introduces, in some ways, philosophies of series production in the space sector where one-off instruments, prototypes are normally used. “.
“The need to produce 26 substantially identical chambers – comments Salatti- has posed unprecedented difficulties both in terms of the development of such a complex payload, and in terms of the satellite that will have to manage it optimally in flight “.” The Critical Milestone Review was a necessary step for Plato: the fact of having successfully overcome it gives an additional charge to the team members to face the second and final implementation phase of the mission “adds the Asi Program manager who sends”a big applause to the group of Italian technologists, researchers and engineers engaged at various levels in the development of the payload “.
The next milestone for the Plato mission is the satellite’s Critical Design Review in 2023, at which time the detailed design of the entire spacecraft will be checked before proceeding with its assembly. The launch is currently scheduled for late 2026 and, once in space, Plato will travel to point L2 of the Earth-Sun system, 1.5 million kilometers from Earth, in the opposite direction to the Sun.
From this point Plato will observe more than 200,000 stars during its four years of rated operation looking for regular decreases in their light caused by the transit of a planet through the star’s disk. Asi and Inaf explain that analyzing these transits and stellar light variations will allow scientists to accurately determine the properties of exoplanets and their host stars.