Russia’s Proton rocket returned to service June 7, almost one year to the date from vehicle’s last flight, delivering a U.S. telecommunications satellite into geostationary transfer orbit.
The Proton last launched almost exactly one year ago, having been grounded by technical issues since then.
The first launch of Russia’s Proton rocket in nearly a year is now scheduled for June 7, a nine-day slip driven by a review of the ground systems at the rocket’s launch site.
Nearly every engine stockpiled for use on upper stages of Proton rockets has defects, investigation concludes
The head of state rocket engine manufacturer Energomash, said that 71 engines require "complete overhauls" to correct defects found.
International Launch Services is adding a larger payload fairing for its Proton rocket, but deferring development of one of two smaller versions of the vehicle announced last year.
International Launch Services, the commercial arm of Proton rocket manufacturer Khrunichev, says it still expects to complete all three launches planned for 2017 once Proton returns to flight.
Russian media reported that test firings found problems with engines used in the second and third stages of the rocket.
International Launch Services on Sept. 13 announced two new variants of its Proton rocket that will be sized to launch smaller geostationary satellites.
Europe’s Arianespace launch-service provider — the only one of the three principal commercial launch operators not grounded by rocket problems — might be able to add a supplemental heavy-lift Ariane 5 vehicle to its 2017 manifest if market conditions demand it, Arianespace Chief Executive Stephane Israel said Sept. 8.
An International Launch Services Proton rocket, in the first flight of its latest and potentially final series of upgrades, on June 10 placed the Intelsat 31 commercial telecommunications satellite into geostationary transfer orbit.
The head of Russia’s Roscosmos space agency on March 31 rebutted claims from amateur satellite watchers that the Proton rocket’s upper stage came apart in orbit March 14 shortly after releasing the Euro-Russian ExoMars satellite.
Managers of the Russian rocket are also using contract modifications, including schedule priority on Proton’s launch manifest for commercial missions and other benefits not directly related to prices.
The satellite is owned by the Russian Satellite Communications Co. of Moscow, which has suffered from Proton’s error-prone record in the past six years more than any other company.