Proton Makes Successful Return to Flight

Proton launches EchoStar XXI satellite. (Credit: Roscosmos)

Russia’s workhorse Proton booster made a successful return to flight early Thursday after being grounded for one day short of a year.

A Proton rocket roared off the pad at Baikonur Cosmodrome with the EchoStar XXI communications satellite. Officials say the spacecraft was delivered to its proper orbit and is functioning as designed.

Proton has been grounded since June 9, 2016. While launching the Intelsat 31 communications satellite, the Proton’s second stage under performed. The third stage fired longer than planned to get the spacecraft to its intended orbit.

An investigation found that lower quality materials had been substituted during engine production. The manufacturing problem also affected engines made for Soyuz boosters.

The quality control problems have lowered Russia’s launch rate. The Proton flight was only the sixth launch as we approach the mid-point of 2017. That figure includes two Soyuz rockets launched from ESA’s spaceport in French Guiana.

Russian officials said this week there are four additional Proton launches planned this year, two for commercial customers and two for the Russian government.