The power satellites are presented as a solution for the future, because they are identical payload lighter than chemical propulsion. In fact, they carry much less fuel which limits their mass. In other words, a communication satellite 5 or 6 or 3 passes tons 4 tons with this technology! However, this is not as easy as it has the air ...
What must be understood is that the weight saving offers two choices for operators: either they use it to lower the cost of launch (a pitcher lowest), or they take the opportunity to increase the payload.
So until the announcement of the arrival on the market of ITS-12, it was thought that they would prefer that affect weight gain to lower launch costs and therefore guide the market power to satellites a unique range of models from March to April tonnes. http://enjoycoloring.com/tag/halloween/ A market segment that strongly dessert Arianespace and its dual launch strategy which favors the Falcon 9 launch vehicle to offers of abnormally low prices.
He had not reckoned on the 5.3 tons of ITS-12 throwing a real bombshell. SES took everyone off balance and offers, in fact, one of the world's most powerful satellites with energy 19 kW. If a chemical propulsion craft would pick the same payload, he was so big and heavy that no rocket in use today would be able to run it!
Going back to ITS-12 and 5.3 tonnes, only Proton and Arianespace are capable of launching such high loads transfer orbit geostationary. The current version of the Falcon 9 capped at 4.8 tonnes. All is not lost however, for the young American society that promises the coming years, a pitcher ( Falcon Heavy ) 20 tons of performance to geostationary transfer orbit.
Finally, note that power satellites do not have that benefit. More expensive to build than chemical propulsion, they have the main drawback within several months to reach the orbit. For example, according to the launcher to be used (Ariane 5 or Proton), ITS-12 will between three and six months to win the geostationary orbit.
