Vehicle Description
The Proton-M features modifications to the lower stages to reduce structural mass, increase thrust, and fully utilise propellants. A closed-loop guidance system is used on the first stage, which allows more complete consumption of propellant. This increases the rocket's performance slightly compared to previous variants, and reduces the amount of toxic chemicals remaining in the stage when it impacts downrange. It can place up to 21 tonnes (46,000 lb) into low Earth orbit. With an upper stage, it can place a 3 tonne payload into geosynchronous orbit, or a 5.5 tonne payload into geosynchronous transfer orbit. Efforts were also made to reduce dependency on foreign component suppliers.
Most Proton-M launches have used a Briz-M upper stage to propel the spacecraft into a higher orbit. Launches have also been made with Block-DM upper stages, namely the Block DM-2 when launching GLONASS spacecraft, and a scheduled launch with two Yamal satellites, using a Block DM-3. As of 2009, no Proton-M launches have been made without an upper stage, however this configuration is manifested to launch the Multipurpose Laboratory Module and European Robotic Arm of the International Space Station, currently scheduled to be launched together in 2013.
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