Mission Status


BREAKING NEWS! The ESA Science Programme Committee (SPC) has adopted Ariel in the meeting held on 12 November 2020. The mission adoption was the last study phase milestone before proceeding to mission implementation.

See the news release: Ariel moves from blueprint to reality.


The path from the M4 call for proposals until mission adoption is summarised in the figure below:



Everything inside the green rectangle in the figure above has been accomplished. Currently (autumn 2020) ARIEL is in the final phase of the Definition Study (phase B1 - red rectangle in the figure above) currently undergoing the Mission Adoption Review (MAR), as part of the activities ultimately leading towards the next major mission miletone, the Mission Adoption planned for November 2020. In bulletform text:

  • 2014 August: The Call for proposals for the M4 mission was issued by ESA.
  • 2015 January: The ARIEL proposal was submitted to ESA. It was one of 27 proposals competing for the M4 opportunity.
  • 2015 June: After programmatic and scientific assessment three proposals were downselected to undergo industrial studies. The first phase (phase 0) was Concurrent Design Facility (CDF) studies conducted in ESA/ESTEC in the summer of 2015.
  • 2016-17: Assessment Study (phase A), industrial studies supported ESA and proposal teams. Each proposal was studied in parallel by two industral consortia in competition. For ARIEL these were Astrium Defence and Space (ADS) in Toulouse, France, and Thales Alenia Space (TAS) in Cannes, France.
  • 2018 March: ARIEL was selected by the ESA Science Programme Committee (SPC) as the M4 mission. The ARIEL payload module will be provided by the ARIEL Consortium. The selected mission is described in the 'Asessment Study Report', normally referred to as the 'Yellow Book'.
  • 2018-19: Definition Study (phase B1), industrial studies by ADS and TAS supported ESA and the ARIEL Consortium, who continue to work on the payload module.
  • 2020: The mission proposed for adoption is described in the 'Definition Study Report', normally referred to as the 'Red Book', publicly issued in November 2020. The Mission Adoption Review (MAR) was underway in the second quarter 2020, and the Mission Adoption by the SPC was planned for its November 2020 meeting.
  • ​​​​​​​2020 November 12: The ESA Science Progamme Committee (SPC) adopted Ariel; see Ariel moves from blueprint to reality.

With a successful mission adoption achieved the actual implementation of the mission will start in 2021, with launch by an Ariane 62 launcher planned for 2029, followed by a nominal 4 year inflight mission, with a possible extension to 6 years inflight.