Following the success of the ERS satellites and Envisat, which addressed Earth science issues of a global nature, Earth Explorers are smaller research missions dedicated to specific aspects of our Earth environment whilst demonstrating new technology in space.
Earth Explorer missions focus on the atmosphere, biosphere, hydrosphere, cryosphere and the Earth's interior with the overall emphasis on learning more about the interactions between these components and the impact that human activity is having on natural Earth processes.
GOCE (Gravity Field and Steady-State Ocean Explorer)
Launched on 17 March 2009; mission ended in November 2013
How does the gravity field affect ocean currents and sea level?
GOCE is dedicated to measuring the Earth's gravity field and modelling the geoid with unprecedented accuracy and spatial resolution to advance our knowledge of ocean circulation, which plays a crucial role in energy exchanges around the globe, sea-level change and Earth interior processes. GOCE will also make significant advances in the field of geodesy and surveying.
SMOS (Soil Moisture and Ocean Salinity)
Launched on 2 November 2009
Is climate change accelerating the water cycle?
SMOS is observing soil moisture over the Earth's landmasses and salinity over the oceans. Soil moisture data are urgently required for hydrological studies and data on ocean salinity are vital for improving our understanding of ocean circulation patterns.
Launched on 8 April 2010
Are the ice caps shrinking?
CryoSat is acquiring accurate measurements of the thickness of floating sea-ice so that seasonal to inter-annual variations can be detected, and also surveying the surface of continental ice sheets to detect small elevation changes. Data from CryoSat will help determine regional trends in Arctic perennial sea-ice thickness and mass, and determine the contribution that the Antarctic and Greenland ice sheets are making to mean global rise in sea level. This satellite replaces the original CryoSat which was lost owing to a launch failure in 2005.
Launched on 22 November 2013
How fast is the Earth's magnetic shield weakening against solar radiation?
Swarm is a constellation of three satellites that will provide high-precision and high-resolution measurements of the strength and direction of the Earth's magnetic field. The geomagnetic field models resulting from the Swarm mission will provide new insights into the Earth's interior, further our understanding of atmospheric processes related to climate and weather, and will also have practical applications in many different areas such as space weather and radiation hazards.
ADM-Aeolus (Atmospheric Dynamics Mission)
Scheduled for launch in 2016
How does measuring the wind improve weather forecasting?
ADM-Aeolus will be the first space mission to measure wind profiles on a global scale. It will improve the accuracy of numerical weather forecasting and advance our understanding of atmospheric dynamics and processes relevant to climate variability and climate modelling.
EarthCARE (Earth Clouds, Aerosols and Radiation Explorer)
Scheduled for launch in 2018
To what extent do clouds and aerosols influence global warming?
EarthCARE is being implemented in cooperation with the Japanese Aerospace Exploration Agency (JAXA), and addresses the need for a better understanding of the interactions between cloud, radiative and aerosol processes that play a role in climate regulation.
Scheduled to launch around 2020
What is the state of Earth's forests and how are they changing?
By determining the amount of biomass and carbon stored in forests, the Biomass mission will provide crucial information about the state of our forests and how they are changing. This information will be used to further our knowledge of the role forests play in the carbon cycle.
Earth Explorer 8: As a result of the Call for Proposals released in October 2009 for the eighth Earth Explorer, the Florescence Explorer (FLEX) and CarbonSat missions are at the end of Phase A/B1. A User Consultation Meeting was held in September 2015. The final selection will be made at the end of November 2015.