ESA Calls for Proposals for Medium-size Mission

American Astronomical Society: This announcement is on behalf of Luigi Colangeli of the European Space Agency: The European Space Agency's Director of Science and Robotic Exploration solicits from the broad scientific community proposals for the competitive selection of mission concepts to be candidate for the implementation of a medium-size, or M-class, mission (M4) for launch in 2025. Interested parties planning to submit a proposal are requested to send a letter of intent by 12 noon CEST on 1...