The second satellite in ESA’s Earth Explorer series – the Soil Moisture and Ocean Salinity (SMOS) mission – and the second demonstration satellite under ESA’s Project for Onboard Autonomy (Proba-2) were launched into orbit last night from northern Russia.
The satellites were launched atop a Rockot launch vehicle provided by Eurockot GmbH. Liftoff from the Plesetsk Cosmodrome in northern Russia took place at 01:50 UTC (02:50 CET) on Monday 2 November.

Both satellites are currently circling the Earth on their respective sun-synchronous orbits, at an altitude of some 760 km in the case of SMOS and 725 km in that of Proba-2. The Proteus mission control centre operated by the Centre National d’Etudes Spatiales (CNES) in Toulouse, France, is in control of SMOS on behalf of ESA, while the Proba control centre, at ESA’s tracking station in Redu, Belgium, has taken over Proba-2.
Proba-2 is planned to reach operational status in two months’ time. The highly innovative payload onboard SMOS will take longer to check and calibrate, and the spacecraft will enter fully operational mode within six months.
SMOS will play a key role in the monitoring of climate change on a global scale. It is the first ever satellite designed both to map sea surface salinity and to monitor soil moisture on a global scale. It features a unique interferometric radiometer that will enable passive surveying of the water cycle between oceans, the atmosphere and land. SMOS is a 658-kg satellite developed by ESA in cooperation with France’s CNES and Spain’s Centro para el Desarrollo Tecnológico Industrial (CDTI). It is based on the Proteus small satellite platform designed and built by Thales Alenia Space and its payload is composed of a single instrument, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), developed by EADS CASA Espacio.

SMOS is the second satellite launched under the Earth Explorer programme conducted by ESA to foster the acquisition of new environmental data for the science community. It follows the Gravity and steady-state Ocean Circulation Explorer (GOCE), also launched on a Rockot, in March 2009.

Travelling piggyback on the launch of SMOS, Proba-2 is a follow-on to the highly successful Proba-1 satellite launched in 2001. It will demonstrate 17 advanced satellite technologies –such as miniaturised sensors for ESA’s future space probes and a highly sophisticated CCD camera with a wide angle view of about 120º – while carrying a set of four science instruments to observe the Sun and study the plasma environment in orbit.  With a launch mass of 135 kg, Proba-2 is a much smaller satellite, “but like its predecessor Proba-1, it is aimed at demonstrating a wide range of technologies, both for future satellite systems and for space science instruments. Among these is a demonstration model of a miniaturised startracker developed for ESA’s BepiColombo mission to Mercury and the future Solar Orbiter probe.

Source: ESA.