Thursday, July 25, 2013 was a very exciting day for the group I work with at Astrium as it saw the launch of Alphasat -- the largest European telecom satellite ever built -- from French Guiana on an Arianne 5 launcher.
This is the first mission for the new Alphabus satellite platform (commonly called a bus). But most importantly for my group at Astrium, it hosts the Alphasat payload, which is the most advanced telecommunications processor developed in Europe, and which will be used by Inmarsat to extend the range of services already offered. This satellite is the most sophisticated Inmarsat and GEO mobile mission ever. Since I've been involved with this project since I started working here, this was a pretty exciting moment for me.
The payload includes a number of these Alphasat processors.
The Alphasat payload generates a number (in excess of 400) of small spot beams. These are reflected via a large reflector mounted above the satellite onto the Earth. The area serviced by the satellite is illustrated in the figure below. The satellite can also provide a number of regional beams and a global beam. To achieve all of this, the payload processor performs two terra operations per second.
Alphasat cell coverage.
Mobile terminals within a cell can communicate with the satellite, which then communicates back to a base station. The base station then connects to the PSTN (public switched telephone network) or data services, thereby completing the link (click here to see a video depicting this process).
The payload consists of eight processors, which provide either forward (station-to-mobile) or return (mobile-to-station) links, thereby supporting bi-directional communications.
Over the next few weeks, the satellite will be moved into the correct orbit and start to be brought into operation. As the satellite undergoes its initial in-orbit verification, I am sure everyone involved in the project will be watching with great excitement.
Click here to discover more about this project.