MOSCOW, September 13. /TASS/. The first stage engine for Russia's Sarmat ballistic missile has passed fire tests, so the missile’s pop-up tests may be held at the end of the year, a source in the defense-industrial complex has told TASS.

"The last series of fire tests was successful. The technical glitches identified earlier have been eliminated," he said.

Currently, work is in progress on technical documentation. It is to be completed in November. According to the most optimistic forecasts Sarmat’s pop-up tests will be carried out in November or December," the source said.

Even in that case, he added, the missile may begin to be flight-tested no earlier than the end of the first quarter of 2017, because at the moment the research and development program is no less than seven months behind time.

TASS has no official confirmation if this is really so.

Sarmat is expected to replace the missile R-36M2 Voyevoda. The new missile’s payload is expected to grow to ten tonnes (against approximately 8.75 tonnes of its predecessor). Sarmat is scheduled to go operational at the end of 2018.