SES's Astra 2G mounted to a Proton rocket. Credit: International Launch Services

PARIS — Satellite fleet operator SES’s Astra 2G satellite, whose Nov. 28 launch on a Russian Proton rocket was scrapped following a last-minute issue with the rocket’s Breeze-M upper stage, will now cede its place on the Proton launch manifest to Gazprom Space Systems of Moscow, according to Russia’s Roscosmos space agency.

As a result, Gazprom’s Yamal-401 telecommunications satellite is scheduled for launch Dec. 15, with the Astra 2G slated for a Dec. 28 launch date.

Despite its Russian pedigree, Gazprom’s Yamal-401, like SES’s for Astra 2G, is a commercial launch contract managed through International Launch Services of Reston, Virginia.

The rocket to be used for Astra 2G was on the launch pad with the satellite when a gyro on the Breeze-M stage gave errant readings two days before the scheduled liftoff. The rocket was removed from the pad and both the Breeze-M and the Astra 2G were taken off.

The gyro manufacturer in St. Petersburg, Russia, has subsequently tested the gyro in question and replaced it with a spare.

In a Dec. 8 statement, ILS said the Yamal-401 and Astra 2G launches had been advancing in parallel before the gyro problem at the Baikonour Cosmodrome spaceport in Kazakhstan.

“In principle, the Breeze-Ms are interchangeable, but having to reload and retest flight software would have resulted in additional days of delay,” ILS said in its statement. “So due to the readiness of the Yamal-401 mission, it logically moved ahead of Astra 2G, with both missions scheduled to launch this month.”

In addition to its conventional telecommunications payload, Astra 2G carries X- and military-Ka-band transponders that the Luxembourg government plans to use as part of a joint venture with SES called Govsat.

Luxembourg’s reservation of these military frequencies expires this month. With Astra 2G now delayed to Dec. 28, Luxembourg may be obliged to find a satellite already in orbit, carrying the same frequencies, and move it to the government-registered orbital slot to retain its rights.

Peter B. de Selding was the Paris bureau chief for SpaceNews.