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N° 62–2001: New spacecraft to preserve our planet and the environment

30 October 2001

Three hundred leading scientists in the field of climate and environmental research using Earth Observation satellites meet this week in Granada (Spain) to push forward the European Space Agency's Living Planet programme aimed at advancing our understanding of the interactions between the atmosphere, the oceans, and the land, to enable mankind to understand the Earth as an integrated system.


It all started in 1996, when the Earth Explorers missions were set on their way, and it continued in 1999, when the first two pioneering spacecraft missions- currently under development- were selected; one addressing the Earth's Gravity field and global ocean circulation (GOCE), the other studying the global dynamic wind-field in the lower atmosphere (Aeolus-ADM). And the story goes on today as, for the second cycle, ESA has again chosen Granada as the venue for the important decision on which satellite missions will fly next.

The Earth Explorers are the research driven component of ESA's Living Planet programme seeking to advance the understanding of the different Earth system processes, in developing our knowledge about the Earth, preserving our planet and its environment and managing life on Earth in a more efficient way. In the long term, the programme also contributes to applications such as the management of the Earth's environment and its resources as well as mitigation of natural and human-induced hazards.

The Earth Explorers consist of two mission types, the Core and the Opportunity missions. Core missions are large research/demonstration missions led by ESA. Opportunity missions are small research/demonstration missions providing the means for a more rapid response to new ideas and can either be led by ESA or by other organisations.

On 30 and 31 October in Granada, the new suite of Explorer-Core Mission candidates, proposed by Europe's leading scientific experts, will be evaluated by peer review panels - building the base for a recommendation that they later be launched into orbit. Five satellite missions have been defined and proposed. Three of them, based on their scientific excellence, will be recommended to go forward for feasibility studies. Two are planned to be launched after a further selection process. The mission candidates are:

ACECHEM (atmospheric Composition Explorer for CHEMistry and climate interaction). A combination of spectrometers will investigate how human-induced chemical alterations to the lower atmosphere (troposphere) and upper atmosphere (stratosphere) may go on to cause climate change.

EarthCARE (Earth Clouds, Aerosol and Radiation Explorer). Instruments, including radar, lidar, imager, radiometer, and spectrometer will peer closely at the interaction between clouds, aerosol and radiation to better understand their impact on climate. This is a joint European - Japanese candidate mission.

SPECTRA (Surface Processes and Ecosystem Changes Through Response Analysis). A high-performance imaging spectrometer and a thermal imager will study the relationship between vegetation and climate change across the worlds entire ecosystems.

WALES (Water vapour and Lidar Experiment in Space) A Lidar - a laser-based device that works on the same principle as radar does - will map atmospheric water vapour concentrations.

WATS (Water vapour and temperature in the Troposphere and Stratosphere). A flotilla of small satellites will measure tropospheric and stratospheric humidity and temperature by checking how GPS radio signals are bent by passage through them.

These Earth Explorer missions all build on the experience gained with their larger predecessors ERS-1 and 2, launched in 1991 and 1995 respectively, which provided us with a wealth of data giving major insight into climate processes particularly involving oceans and ice sheets. They will also follow up Envisat, the largest and most comprehensive environment and climate research satellite ever built, which is ready to be launched in January 2002. The Core Explorers are very specific dedicated science missions, much smaller than their predecessors, weighing not more than two tons and keeping to an overall budget of maximum 400 Meuro, from start of development until end of operations.

The recommendations of the peer review teams will be passed on to ESA's Earth Science Advisory Committee and to the Agency's Earth Observation Programme Board later in November. After that, the candidate missions retained will undergo full feasibility studies and finally ESA should start building the satellites for two out of three missions studied.

More detailed information can be found on ESA's new Living Planet webpages launched earlier in October:

For more information, please contact :

Dr Mike Rast

Earth Sciences Division

Tel.: +31.71.565.4465

Fax: +31.71.565.5675


For further information:

Dr Mike Rast, ESA/ESTEC

Tel: +31.71.565.4465

Fax: +31.71.565.5675