The European Space Agency (ESA) has ordered the first Sentinel Earth Observation satellite dedicated to the Global Monitoring for Environment and Security (GMES) program from Thales Alenia Space.

The €229m agreement was signed this week at the International Paris Air Show, and contracts Thales Alenia Space to design, develop and integrate a satellite that will carry a C-band Synthetic Aperture Radar, known as SAR.

Based on a PRIMA platform, developed by Thales Alenia Space for the Italian Space Agency, the satellite will weigh 2,280kg and will look at the Earth in strips of up to 700km with a ground resolution between five and 25m.

The Sentinel-1 satellite will be used in Earth observation missions co-funded by ESA and the European Commission, and is scheduled to be launched in 2011.

Separately, Saudi Arabian satellite operator Arabsat has awarded a contract to a partnership of Astrium and Thales Alenia Space to build its fifth generation satellites.

A contract for the first two satellites, Arabsat-5A and BADR-5, was signed in Riyadh, Saudi Arabia, last week.

The new satellites play a part in Arabsat’s expansion plans over the Middle East and North Africa over the next 20 years.

Astrium will supply platforms and integrate the satellites, while Thales Alenia Space will design and build the communications hardware. The team will also upgrade the ground control units for the expanded satellite fleet.

The Arabsat-5A, a Eurostar E3000 model, will have a launch weight of 4,800kg and a spacecraft power of 11kW at the end of its 15-year service lifetime.

The satellite will feature 16 active transponders in C-band and 24 in Ku-band. It will take over from the Arabsat-2B and provide a larger range of satellite communications services at 30.5 degrees east, such as television broadcasting, telephony and business communications over sub-Saharan Africa, North-Africa and the Middle East.

The BADR-5 will have a launch mass of 5,400kg and a spacecraft power of 14kW at the end of its lifetime. It will also have 56 active transponders in Ku-band and Ka-band, and its primary function will be to provide in-orbit back-up services for the BADR-4 and BADR-7.

Located at 26 degrees east, the BADR-5 will also support the expected boom of HD-TV and the development of interactive services.

Arabsat has chosen Arianespace and ILS/Proton to launch the satellites by 2010.