Russia launched three Glonass-M navigation satellites March 2 as part of an ongoing effort to replenish its version of the United States’ constellation of GPS satellites.

The trio of Glonass-M satellites — the second such batch to launch in less than three months — were lofted into orbit by a Proton M rocket that blasted off from BaikonurCosmodrome’s Site 81 at 3:19 a.m. local time.

Several hours after liftoff, Russian space officials  confirmed that the satellites reached their orbit and all systems on board the new spacecraft were working normally.

Not counting the three newly launched satellites, Russia has 18 operational Glonass satellites, three in the process of activation, and two temporarily out of service, according to a Russian space agency Web site. Three more Glonass satellites are slated to launch Aug. 10.

The three latest Glonass-M satellites were supposed to have launched last October, but officials postponed deployment after a Glonass satellite already on orbit had to be shut down due to the failure of an on-board signal generator. The failure prompted the return of the yet-to-be-launched Glonass-M satellites to the manufacturer, ISS Reshetnev of Krasnoyarsk, Russia’s biggest satellite builder. The satellites launched March 2 — two refurbished satellites and one new satellite — were shipped to Baikonur between late January and early February.

Nikolai Testoedov, the head of ISS Reshetnev, told the semi-official Interfax-AVN news agency in a recent interview that  last summer’s in-flight problem was traced to an imported electronic chip in an on-board component supplied by Russian Space Systems, the country’s chief developer of spacecraft avionics.

Proton’s March 2 launch was the rocket’s third flight this year. The heavy-lift rocket is due to launch again March 20 carrying the Echostar 14 telecommunications satellite for Englewood, Colo.-based Echostar Communications. The launch was booked through International Launch Services of Reston, Va.