ESA: Eutelsat-9B satellite with its EDRS-A payload

The Eutelsat-9B satellite with its EDRS-A payload is shown in the anechoic test chamber of Airbus Defence and Space (EADS) in Toulouse, France. It completed its final antenna pattern tests today.

EDRS-A is a hosted package as the first of two nodes of the European Data Relay System set to be launched next year.

Also known as Europe’s SpaceDataHighway, EDRS will use cutting-edge laser technology to capture and relay information gathered by Earth-observing satellites.

By travelling via EDRS’s high-speed links and stationary position over Europe, the satellites’ data reach the ground in near-real time.

While EDRS-A’s Laser Communication Terminal is being checked for flight, the terminals on Copernicus’ Sentinel-1A and Alphasat telecom satellite are already fully operational in space, ready to demonstrate their ground-breaking capabilities for multi-gigabit optical communications in space.

On Friday, 28 November the first Earth observation image gathered by Sentinel-1A and relayed to a ground station at the DLR German Aerospace Center in Oberpfaffenhofen,

Germany, via Alphasat will be presented at an event at ESA’s European Space Operations Centre in Darmstadt, Germany.

ESA EADS Astrium Alphasat: Deploys Massive 11m Antenna

ESA's Alphasat, Europe's largest-ever telecom satellite, reached a temporary position in the geostationary ring last weekend, where it deployed its 11 m-diameter main antenna over the course of a day - marking ten days in orbit and completing one of the final steps towards starting services.

It will stay in this slot for several weeks while Inmarsat together with ESA continue testing the telecom payload, the backup units on the Alphabus platform and ESA's four hosted payloads.

Several major milestones have been met over the past few days, including rising to geostationary altitude after separation from its Ariane 5 launcher, and deploying its twin four-panel solar wings, spanning 40 m.

The panels rotate automatically, following the Sun, while Alphasat's sophisticated attitude control system tracks its position above Earth.

All of these milestones were assured by a team from EADS Astrium, the Alphasat prime contractor, managed by Inmarsat.

In a cooperative effort unprecedented in Europe, the team was supported by ESA and France's CNES space agency, as well as Thales Alenia Space for Alphabus platform operations.

Alphasat uses the first flight model of the new platform. The Alphabus line, developed by Astrium and Thales Alenia Space, under a joint contract to ESA and CNES, is Europe's response to market demand for increased broadcasting services.

It accommodates missions with up to 22 kW of payload power and mass up to two tonnes. As a high-power multipurpose platform, it gives European industry an unprecedented and unique position in the global telecom market.

Jena-Optonik's Astro APS startracker was the first hosted payload to be switched on, measuring the satellite's attitude.

Alphasat joins Inmarsat's award-winning I-4 satellite fleet, which has been powering global broadband connectivity for government and commercial customers in the L-band since 2009.

The new satellite with its new-generation advanced payload will provide additional mobile satellite communications capacity over Europe, the Middle East and Africa.

ESA Alphasat ready for launch

Ready for launch tomorrow, Alphasat – Europe's largest telecommunications satellite – will serve as a testbed for advanced space technologies at the same time as it works on its day job as part of the Inmarsat satellite fleet.

Developed through a public–private partnership with Inmarsat, the 6.6 tonne Alphasat is the first flight of the new 'Alphabus' European telecom platform.

At the same time Alphasat is also flying a quartet of 'technology development payloads' – a pair of them conspicuous in gold- and silver-coloured multilayer insulation here, against this face of the satellite's predominantly black covering.

The higher up of the two gold-wrapped packages is a Q/V-band payload to investigate the viability of higher frequencies for radio communications as existing frequency bands become progressively overcrowded.

Developed by Italy's ASI space agency, the payload was recently renamed for its late inventor, Aldo Paraboni.

Just above it is a black box housing an environmental testing and radiation sensor. Provided by Efacec in Portugal, the sensor tests electronic components and solid-state memory devices against space radiation.

To the right of this is an experimental startracker, a standard device for attitude control that images constellations to deduce a satellite's orientation.

Developed by Jena Optronik, this startracker incorporates 'active pixel sensor' technology – also the basis of modern digital and smartphone cameras – that combines decreased power requirements with increased robustness for smaller, more powerful imagers.

Below it, the second payload wrapped in gold insulation is an advanced laser communication terminal, capable of locking onto rapidly moving satellites in low orbits thousands of kilometres beneath Alphasat's fixed geostationary position and receiving up to 1.8 gigabits of data per second.

Developed by Tesat in Germany and furnished by Germany's DLR space agency, this terminal is trialling technology to be used for ESA's pair of European Data Relay System satellites later in the decade, establishing a data highway that will be employed in turn to relay results from ESA's Earth-observing Sentinel satellites to end-users.

ESA EADS Alphasat experiences Deep Space on Earth: Interspace

Tucked away in a vacuum chamber for several months, Europe's largest telecom satellite has faced the harsh conditions it will deal with once it is launched into space this summer.

Testing at Intespace in Toulouse, France, simulated conditions close to those Alphasat will experience in flight, including the intense cold of its transfer orbits in the early stages of the mission.

Not only was Alphasat's ability to control its temperature tested, but other features were also put through their paces to ensure everything can run under the extreme cold and hot conditions.

"If you were going to test a new car for extreme conditions, you would probably want to do the same thing: not only check the heating and air conditioning, but also make sure that the engine, brakes, ignition and radio work in low temperatures as well as high," explained Philippe Sivac, ESA's Alphasat acting project manager.

To monitor the satellite inside the large chamber, nearly 600 temperature sensors were attached in key locations. A satellite the size of Alphasat can also carry up to 400 flight thermal sensors.

Readouts are displayed in real time, together with the satellite's internal data to help build an overall picture for the team monitoring Alphasat around the clock.

Running Alphasat under very stable thermal situations showed that the thermal-mathematical model is well suited to predict the temperatures in orbit.

"Finally, the performance and functional tests show that all the electronics and software perform as expected even at extreme temperatures."