As part of its Earth Observation Envelope Programme (EOEP), the European Space Agency (ESA) announces an opportunity for scientists from the Earth Observation (EO) community in ESA Member States, Canada and Slovenia to prepare proposals for ideas to be assessed as potential Earth Explorer Core Missions. These missions will be used to conduct research in the field of EO and/or to demonstrate the potential of new innovative EO techniques of relevance to both the scientific and the application-oriented user communities.

The Earth Observation Envelope Programme is a rolling programme designed to lead European efforts in EO from space. The Research Mission element of the programme consists of a series of missions addressing critical Earth science issues. In the past, eight Earth Explorer missions have been selected for implementation, namely four Earth Explorer Core Missions, GOCE (Gravity field and steady-state Ocean Circulation Explorer), Aeolus (Atmospheric Dynamics Mission), EarthCARE (Clouds, Aerosols and Radiation Explorer), Biomass (forest carbon mission); and four Earth Explorer Opportunity Missions1, CryoSat (polar ice monitoring), SMOS (Soil Moisture and Ocean Salinity), Swarm (Earth’s magnetic field and environment), and FLEX (Fluorescence Explorer).

The motivation behind this Call is the Agency’s wish to engage the scientific community as far as possible in determining and advancing the content of the Earth Observation Envelope Programme. The Agency wants to achieve a clear appreciation of the science community's views on what mission ideas will provide the highest scientific return and the best response and solution to scientific and societal challenges (c.f., Earth Observation Science Strategy for ESA: A New Era for Scientific Advances and Societal Benefits, ESA SP-1329/1 and ESA’s Living Planet Programme: Scientific Achievements and Future Challenges – Scientific Context of the Earth Observation Science Strategy for ESA, ESA SP-1329/2, European Space Agency, Noordwijk, the Netherlands, 2015).

Taking into account the experience from previous calls, and in line with the spirit of the programme, the Agency is soliciting ideas for missions to be implemented as ESA-led Earth Explorer Core missions. Mission candidates will be selected from the proposed ideas on the basis of their innovation and scientific excellence. The total cost of the mission should not exceed 400 M€ to ESA (at 2017 economic conditions). However, proposals with more cost-effective solutions are strongly encouraged.

A response to the Call may be made by scientists from ESA Member States, Canada and Slovenia, or teams of scientists, where proposing teams may also include scientists from non-ESA member states.

1Nowadays referred to as "Fast-track" missions.

Release of the call 25 September 2017
Deadline Letter of Intent (LOI) and List of core scientific team 15 December 2017, 12:00 hrs (noon) CET
Proposal submission deadline 2 March 2018, 12:00 hrs (noon) CET
Announcement of results End of September 2018