International Launch Services, American-Russian joint venture Company which offers Proton rockets launched from Baikonur Cosmodrome, announced on October 12, 2016, that they have signed first contract for their new launch vehicle.
ILS announced officially, that have signed first contract for using their planned medium version of Proton-M rocket. This launch vehicle is at the moment in the early phase of development, but according to ILS, it should be ready for its first commercial flight in 2019 (maiden flight is planned for 2018). First commercial flight was contracted to Eutelsat Communications and it is part of agreement signed one year ago and known as Multi-Launch Agreement (MLA). It was not unveiled, which satellite will be delivered on atop of Proton Medium, but it is sure that launch will be conducted in 2019-2020 timeframe; just as with Proton-M, Proton Medium will be also launched from Baikonur Cosmodrome. ILS signed also another agreement with Eutelsat Communications covering another launch, but this time with Proton-M rocket. This mission was already scheduled for 2018 and covers two spacecrafts delivered to orbit during single flight. First will be Eutelsat-5 West B communication satellite by Orbital ATK basing on GEOStar bus (contract for manufacturing this satellite was signed shortly before agreement with ILS). Payload was contracted to Airbus Defence and Space - satellite will be equipped with 35 Ku band transponders. Secondary payload will be MEV - Mission Extension Vehicle also created by Orbital ATK. It is vehicle designed especially for refueling satellites remaining in orbit to extend their operational life. Eutelsat is second customer for MEV, first was Intelsat, which signed contract with Orbital ATK on April 2016. Both satellites, Eutelsat-5 West B and MEV will be launched on atop of Proton-M with Briz-M upper stage.
Proton Medium is downsized Proton-M rocket by Khrunichev State Research and Production Space Center; in fact it is developed simultaneously in two variants – first one is light variant, which will be able to deliver to LEO up to 1.45 t of payload. Second variant is medium sized (this variant is contracted for Eutelsat) will be able to deliver up to 2.2 t. Comparing to Proton, Medium version has decreased payload capacity for 30%; rocket in both variants will be strongly based on Proton-M with wide utilization of its components and subsystems. Navigational equipment, avionics, onboard computers will be probably identical as used for Proton-M, but modified with new flight algorithms created for lighter rocket. Both variants of Proton-M will be based on two stages: lighter version will be equipped with four and heavier with six engines. Again for cost cutting, rocket will utilize proven RD-275M engines liquid fueled with N2O4/UDMH in the first stage and RD-0212 in the second stage. Light and Medium versions will be using Briz-M upper stages, just as Proton-M.