In the latest setback for the Russian space program, one of two defense satellites failed to separate from the Soyuz carrier rocket's upper stage and is believed lost.

The Soyuz-2.1B rocket carrying two satellites was launched Dec. 5 from the Plesetsk cosmodrome in the Russian north-western Arkhangelsk region.

But TASS news agency, citing an unnamed source Monday, acknowledged that the Kanopus-ST satellite "was lost" after “one of the four locks holding the satellite malfunctioned.”

Related: International Space Station shifts orbit position after glitch, Russians say

This was the second launch of the Soyuz-2.1B three-stage carrier rocket that is used for placing payloads into low Earth orbit. The first launch took place in late December 2013, the Defense Ministry said in its statement, according to Reuters.

Earlier this year, the Russian space industry was rocked by several rocket launch failures.

A Proton rocket launched in May developed a problem in its third-stage engine eight minutes into the flight, resulting in the loss of a Mexican communications satellite.

Related: Space station crew: Russia's spinning supply ship total loss

That came just a month after the failure of the second main type of Russian booster rocket, the Soyuz, which suffered a breakdown in its third stage after its launch on April 28.

Related: Russian space capsule docks at International Space Station

An unmanned Progress cargo ship it was carrying was stranded in low orbit and soon fell to Earth over the Pacific, delayng the arrival of the scheduled supplies for a six-person crew at the International Space Station.