After successfully undergoing a rigorous three-month testing programme, the innovative SMOS (Soil Moisture and Ocean Salinity) payload is about to make its journey from ESA's Test Centre in the Netherlands to France, where it will join the platform to form the satellite in preparation for launch next year.

After more than 10 years of research and development, the SMOS mission is adopting a completely new approach in the field of remote sensing by employing a novel instrument called MIRAS (Microwave Imaging Radiometer using Aperture Synthesis). By capturing images of microwave radiation emitted from the surface of the Earth at a specific wavelength, this novel instrument is capable of observing both the moisture in soil and salt in the oceans. MIRAS will be the first-ever 2-D interferometric radiometer in space and will provide much-needed data to learn more about the continual circulation of water between the oceans, the atmosphere and the land the Earth's water cycle, one of the most important processes occurring on the planet and a crucial component of the weather and climate.

Making sure the instrument will withstand the rigors of launch and the harsh environment in orbit is an extremely important part of the mission development. Therefore, with launch scheduled for next year, MIRAS had to undergo an extensive testing programme in ESA's Test Centre.

In balance

After delivery from the instrument prime contractor EADS-CASA in Spain, the testing programme started with determining the instrument's 'mass properties'. This included precisely measuring its overall weight, locating the centre of gravity and the inertia around its three principle axes. These values are crucial for both tuning the launcher trajectory and as input for the satellite's Attitude and Orbit Control System.

Noise

The instrument module consists of a central structure and three deployable arms. These arms were folded up for the
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Contact: Achim Hahne
Achim.Hahne@esa.int
31-715-653-609
European Space Agency
8-Jun-2007