Directv satellite to be launched from floating platform in the Pacific

The Zenit-3SL launch vehicle will be launched with the DirecTV communication satellite on Tuesday within the Sea Launch programme.

The booster will be launched from the floating platform, Odissey, which will cast the anchor at 154 degrees West Longitude in the Pacific, the Russian representation of the Boeing corporation reports.

The self-propelled Odissey platform and the Sea Launch Commander are currently at the launching site.

The Zenit-3SL launch vehicle is to orbit a satellite weighing about 5.5 tons. DirecTV will be placed in geostationary orbit at 119 degrees West Longitude. This will be the second launch this year within the Sea Launch programme.

The DirecTV 7S satellite will expand the TV broadcasting zone of the DIRECTV company. The spacecraft was built by the US Space Systems/Loral company.

The Sea Launch company has been operating on the space launch market through a co-operative arrangement with the Boeing Launch Services and is one of the main service providers in orbiting heavy satellites.

It is more profitable to orbit satellites with the help of the Zenit-3SL launch vehicle launched from the floating platform on the equator than from Russian launching sites. This is the opinion of the spokesman for the Russian space corporation, Energia, which participated in the development of the boost unit for the Zenit rocket within the Sea Launch project.

"This is due to the fact that Baikonur (in Kazakhstan - has been leased to Russia for 49 years) launches at the latitude of 46 degrees inevitably require energy consuming manoeuvres for turning the launch angle into the equator angle," he explained.

According to the expert, the further the launching site is from the equator, the less possible it is to use the effect of the earth spin. If launched from the equator zone, the Zenit launch vehicle can place to the geostationary orbit a satellite weighing twice as much as if it were launched from Baikonur. "Hence the idea of creating a floating missile complex and conducting launches from the area located at 152 degrees Western Longitude," said the expert.

According to him, the Sea Launch complex allows placing satellites weighing up to three tons to the geostationary orbit, up to 6 tons - to the geosynchronous transfer orbit, and up to 11 tons - to low circumterrestrial orbits with the angle of about 90 degrees.