PARIS — The launch of the three European Space Agency (ESA) Swarm satellites designed to study the Earth’s magnetic field has been delayed again, to mid-year at the earliest, due to an inquiry into the Jan. 15 malfunction of the Breeze-KM upper stage of the Rockot vehicle, the rocket’s commercial service provider said Jan. 24.

Swarm’s launch already had been delayed following the February 2011 failure of a Rockot vehicle, a mishap that was traced to the same Breeze-KM stage. The failure resulted in the loss of a Russian government science satellite, and the rescheduling of Swarm’s launch from mid-2012 to spring 2013.

In its most recent mission, the Rockot vehicle, based on the former SS-19 ballistic missile and now produced by Moscow-based Khrunichev Space Center for satellite launches, successfully placed three Russian communications satellites into low Earth orbit following a launch from the Plesetsk Cosmodrome in northern Russia. But after releasing the satellites into their correct orbit, the Breeze-KM shut down before performing its planned post-deployment maneuver.

The maneuver is designed to put the rocket upper stage into a lower orbit to reduce the time it remains in space as another piece of orbital debris. With the lower orbit, it would fall back into Earth’s atmosphere sooner. This kind of maneuver is now being asked of all launch vehicle operators as part of a growing international consensus on the need to reduce the amount of space debris.

A different version of the Khrunichev-built Breeze stage is used aboard Russia’s heavy-lift Proton rocket, and that hardware is subject to a separate Russian government inquiry after a glitch in December, the third involving Proton in 16 months. In addition to the launcher issues, the three Swarm satellites have had to take a back seat to Russian government launches in the Rockot manifest.

Peter Freeborn, marketing manager for Eurockot Launch Services GmbH of Bremen, Germany, a German-Russian joint venture that markets Rockot launches, said Jan. 24 that one more Russian government launch, this one for the Roscosmos space agency, is scheduled before Swarm. Freeborn said a Russian government inquiry into the Jan. 15 problem is under way and that Eurockot expected word soon on the vehicle’s availability for 2013. He said it is reasonable to assume that the Russian government flight will be conducted in time for a Swarm launch sometime this summer, but that no firm word could be given until the inquiry is completed.

ESA Director-General Jean-Jacques Dordain told a Jan. 24 press conference that the ESA satellites have been ready “for some time now” and that the agency wants to have Swarm in operation in time to observe this year’s expected solar maximum, which is when the normal 11-year cycle of solar activity reaches its zenith. The solar maximum had been expected in 2011, then in 2012.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.