PLAnetary Transits and Oscillations of stars (PLATO) is a space telescope under development by the European Space Agency for launch in 2026. The mission goals are to search for planetary transits across up to one million stars, and to discover and characterize rocky extrasolar planets around yellow dwarf stars (like the Sun), subgiant stars, and red dwarf stars. The emphasis of the mission is on Earth-like planets in the habitable zone around Sun-like stars where water can exist in a liquid state. It is the third medium-class mission in ESA's Cosmic Vision programme and is named after the influential Greek philosopher Plato. A secondary objective of the mission is to study stellar oscillations or seismic activity in stars to measure stellar masses and evolution and enable the precise characterization of the planet host star, including its age. History PLATO was first proposed in 2007 to the European Space Agency (ESA) by a team of scientists in response to the call for ESA's Cosmic Vision 2015–2025 programme. The assessment phase was completed during 2009, and in May 2010 it entered the Definition Phase. Following a call for missions in July 2010, ESA selected in February 2011 four candidates for a medium-class mission (M3 mission) for a launch opportunity in 2024. PLATO was announced on 19 February 2014 as the selected M3 class science mission for implementation as part of its Cosmic Vision Programme. Other competing concepts that were studied included the four candidate missions EChO, LOFT, MarcoPolo-R and STE-QUEST. In January 2015, ESA selected Thales Alenia Space, Airbus DS, and OHB System AG to conduct three parallel phase B1 studies to define the system and subsystem aspects of PLATO, which were completed in 2016. On 20 June 2017, ESA adopted PLATO in the Science Programme, which means that the mission can move from a blueprint into construction. Over the coming months, industry was asked to make bids to supply the spacecraft platform. PLATO is an acronym, but also the name of a philosopher in Classical Greece; Plato (428–348 BC) was looking for a physical law accounting for the orbit of planets (errant stars) and able to satisfy the philosopher's needs for "uniformity" and "regularity". Management The PLATO Mission Consortium (PMC) that is responsible for the payload and major contributions to the science operations is led by Prof. Heike Rauer at the German Aerospace Center (DLR) Institute of Planetary Research. The design