About the I-4 Satellites, Used by the Isatphone
The Inmarsat I-4 series of satellites are the most advanced mobilesatellite communication spacecrafts ever launched.
The I-4 constellation is made of three satellites that are part of the 11satellites owned and operated by Inmarsat.
The 11 Inmarsat satellites include the Inmarsat-2 and Inmarsat-3generations. All of the 11 satellites are in a geosynchronous orbit at 22,240 miles above the earth.
The first wholly owned satellites Inmarsat were the Inmarsat-2s launched in the 1990s. The first generation satellites to use spot beam technology were the Inmarsat-3s that were launched in the 1990s.
The I-4 satellites far exceed the power of the Inmarsat-3s by sixty times, creating a new benchmark for satellite communications.
The I-4 life expectancy should provide reliable service until 2020.
Space technology companies from the United Kingdom, Germany, France, Canada and the US invested in the I-4 program costing $1.5 billion
Inmarsat subcontracted European satellite manufacturer EADS Astium to buildthe three Inmarsat-4 satellites. The main body was constructed in Britain. The main body includes the bus which houses the onboard rocket engine and keeps the satellite in its geostationary orbit. The main body also includes the payload which is made up of the communication electronics which was assembled in Portsmouth, Hampshire.
The other main components of the satellite include the antenna, the 9 meter reflector and the 45 meter solar arrays. These components where manufactured in Germany, Canada and the US.
The Inmarsat-4 constellation has power enough to generate hundreds of high powered spot beams.
Each satellite can generate more than 200 narrow spot beams and 19 wide beams. These Beams can quickly be focused anywhere on earth to provide extra capacity when demanded.
The I-4 satellite’s powerful features include a very large body close to the size of a double-decker bus. Solar arrays with an immense wing span of 45 meters. A digital signal processor controls the beam forming, the antennas and the channel allocation. The 9 meter wide reflector when deployed unfurls in orbit like a giant flower. There are both chemical and plasma ion thrusters that keep the satellite in its geostationary orbit.
The I-4 constellation is the most power constellation to this date deployed in orbit providing broadband data and voice communications to areas void of terrestrial communications.