Proton | UR-500 | 8K82 | SL-9
2019-5-30 · Proton modifications for 2011 . In the first decade of the 21st century, developers planned a new series of upgrades to the Proton M rocket and its Briz-M upper stage to increase its payload to geostationary transfer orbits from 6,150 kilograms to 6,300 kilograms.
