Three Earth Explorer candidates go forward
ESA has selected three new Earth Explorer mission candidates—ECO, Keystone and CryoRad—to move to the next preparatory phase, a milestone toward ESA's twelfth Earth Explorer satellite mission.
The decision was taken by ESA's Programme Board for Earth Observation, which considered both scientific relevance and programmatic factors. It followed a July User Consultation Meeting where four mission concepts were scrutinized by the scientific community. ESA's Advisory Committee for Earth Observation then advised on scientific merit and ranked the concepts as ECO, Keystone, CryoRad and Hydroterra+.
ECO would target the global mean Earth Energy Imbalance (EEI), described by ACEO representative Rene Forsberg as the most fundamental climate variable and widely recognized as the most important longstanding knowledge gap in quantifying ongoing climate change. It would also assess the effectiveness of climate mitigation measures. Acknowledging EEI's scientific and societal relevance, ESA and its Member States gave the challenging ECO concept the chance to be investigated further under Earth Explorer 12.
Keystone would provide the first global direct observations of atomic oxygen, together with co-located measurements of temperature, wind and relevant atmospheric constituents in the 50–250 km altitude range, addressing fundamental knowledge gaps in this underexplored part of the atmosphere. As an additional benefit, it would detect metal from space debris entering the atmosphere, which is projected to increase exponentially in the future.
CryoRad was recognized for compelling objectives: directly measuring temperatures and basal conditions within the polar ice sheets. Those measurements would support understanding of ice-sheet dynamics and improve assessments of future global sea level.
ESA Director of Earth Observation Programmes Simonetta Cheli said that over the past two years each of the four mission concepts had been studied extensively, and each represents an ambitious approach to advancing Earth science and innovation. She noted they align with the FutureEO programme and have the potential to deliver new insights into the complex, interconnected processes shaping the planet.