PLATO was proposed to European Space Agency (ESA) by a large consortium of scientists from laboratories all across Europe lead by Dr. Claude Catala (Observatoire de Paris)   in response to the Call for ESA Cosmic Vision 2015-2025. It was selected together with other five M class missions from 52 proposals in the fall of 2007.

After a first assessment study carried out at the ESA/CDF the PLATO mission has been subject of further studies: assessment studies of the whole mission were carried out independently by two industries, and an assessment study of the PLATO payload (telescopes,  on board and ground based data handling)  has been provided by a Consortium of Research Institutes and Universities: the PLATO Payload Consortium (PPLC). These Assessment Phase activities have be completed in the course of 2009, and in January 2010 the Advisory Structure to the Science Programme of ESA has recommended PLATO for the  Definition Phase, in support of the decision by the Science Programme Committee eventually taken in February 2010.

In May 2010, PLATO has entered the Definition Phase: two industries consolidated the study of the Service Mission Module, while the PLATO Mission Consortium (PMC), funded by national agencies, designed the PLATO Payload, the Data Center and prepared the Science activities required for the mission implementation. PLATO successfully completed the Phase A in Jun 2011.

Following the non-selection of PLATO in October 2011 for the M1 or M2 launch opportunities, the ESA Science Programme Committee (SPC) endorsed the solicitation of a proposal to the PLATO Mission Consortium to be a candidate for the M3 launch opportunity in 2022–2024. The PLATO Mission Consortium responded with a proposal for the provision of the payload and science ground segment components formulated in the M3 mission framework, which was accepted by ESA. A major change was the transfer of the leading role from France to Germany, with Prof. Heike Rauer (DLR) as PLATO Principal Investigator. The submitted science case and mission design are summarised in the Assessment study report (ESA/SRE(2013)5). On February 19th 2014 PLATO has been selected by the ESA SPC  for the M3 slot, according to the proposal made by he ESA executive that followed the recommendation by the ESA Space Science Advisory Committee.

The mission Definition study (re)started subsequently, involving three concurrent industrial contracts with Airbus DS, OHB and Thales Alenia Space, for the definition of the mission profile, the satellite, and parts of the payload module. In addition, ESA performed the study of its science ground segment contribution and, together with e2v, of the CCDs procurement. The PLATO Mission Consortium carried out the study of the payload and of their contributions to the science ground segment. The Definition phase concluded with the successful Payload, Science Ground-segment and Science Performance System Requirement Review (PSRR) and Mission Adoption Review (MAR) finalized in May 2016. In June 2016, the SPC approved the PLATO Science Management Plan.

As a result of the MAR recommendations and the mission adoption cost assessment, the mission baseline configuration was redefined to include a payload with 24 normal and 2 fast cameras and four years of nominal science operations, with the requirement that the satellite be built and verified for an in-orbit lifetime of 6.5 years accommodating consumables for 8 years.

PLATO has been adopted  in the ESA Science Programme in Jun 2017.

Current Status:

• Payload: Phase B2 ongoing.
• Satellite: Phase B1 completed in April 2017; selection of Prime ongoing; KOM planned 1 May 2018