Thales Alenia Space has started the development of Sentinel 1B and 3B Earth observation satellites in its Italian and French facilities. These contracts have been awarded to Thales Alenia Space in December 2009, worth 270 million euros, by the European Space Agency (ESA) as part of the Global Monitoring for Environment and Security (GMES) programme.

As prime contractor for Sentinel 1 and Sentinel 3 constellations, Thales Alenia Space is responsible for the design, development, integration and testing of these satellites.

Sentinel 1B and 3B satellites are the duplicate models of Sentinel 1A and 3A satellites that are currently under construction. The satellites are manufactured in the French facility of Cannes as well as in the Italian facilities of Rome and L'Aquila.

Reynald Seznec, President and CEO of Thales Alenia Space, highlights: "The award of the Sentinel 1 and 3 families granted our company an increasingly forefront role in one of Europe's most important environmental projects. They confirm the role and skills gained by Thales Alenia Space in the Earth observation domain."

Sentinel 1A and 1B satellites will image the Earth in swaths of 250 kilometres in diameter with a ground resolution between 5 and 25 metres. They will carry a C-band Synthetic-Aperture Radar (SAR) to provide users with continuous images, day and night, in all weather conditions.

mission objectives and services of Sentinel-1 are: mapping of urban areas and environmental impacts, monitoring of land surface motion risks, surveillance of marine environment, maritime security, monitoring of sea-ice zones, monitoring of forest and climate change.

Key technologies, such as T/R modules and Electronic Front Ends for C-band Synthetic Aperture Radar (SAR) Antenna as well as advanced Data Handling subsystem, are currently under development by Thales Alenia Space. Sentinel-1 satellites will be placed in sun-synchronous near polar orbit.

Luigi Pasquali, Thales Alenia Space Italy CEO, stressed: "The T/R modules, which are the core of the Sentinel 1 radar family, are carried out on our facility of L'Aquila, Italy. The radar T/R module array development on the COSMO-SkyMed constellation enables Thales Alenia Space to consolidate its leading position in the field of Earth observation satellites based on radar technology".

He adds: "Our company is strongly determined to pursue the realisation of this core radar SAR technology in our facility of L'Aquila."

Sentinel 3B, like Sentinel 3A, will be devoted to oceanography and land-vegetation monitoring, carrying two optical payloads (one for Ocean Colour Monitoring and one for measuring Sea Surface Temperature) and a high accuracy ocean altimeter.

It will determine parameters such as sea surface topography, sea and land surface temperature, ocean colour and land colour with high-end accuracy and reliability.

Sentinel 3 family will provide crucial data in areas such as climate change, sustainable development, environmental policies, European civil protection, development aid and humanitarian aid. Sentinel-3 satellites will be placed in a high-inclination, sun-synchronous polar orbit.

The GMES satellite family (Sentinel 1, 2 and 3) will consist of six satellites (two of each type). More specifically, Sentinel-1 satellites (namely 1A and 1B), will guarantee continuous operative availability of C-Band SAR data provided by Envisat and ERS.

In particular, Sentinel 1 family will significantly increase the constellation's performance in terms of review times, operative availability and data management for the extraction of products for end users. Sentinel-2 and Sentinel-3 families will monitor Earth and oceans.

Sentinel 4 and 5 satellites, dedicated to meteorological and climatology missions and focused on the atmosphere composition study, will complete the GMES satellite family.