Russia's doomed Phobos-Grunt mission is expected to re-enter the Earth's atmosphere between Jan. 6 to Jan. 19, but space officials allayed fears that the toxic fuel and radioactive materials will be pose danger when the vehicle makes it fiery plunge.

Some 20 to 30 fragments of the 13.2 metric tons (14.6 tons) spacecraft will survive re-entry, and the areas where the fragments will likely fall will be known only a few days before its plunge, according to the Russian space agency Roscosmos.

Recent estimates show that the probe's fragments could rain down anywhere along a broad swath between 51.4 degrees north to 51.4 degrees south, which would include most of land surface.

Phobos-Grunt carries with it 11 metric tons (12 tons) of highly toxic fuel and experts had warned that if the fuel has frozen, some could survive entry into Earth and pose a serious threat if it falls over populated areas.

Russian space officials, however, said that the toxic fuel, including 10 kilograms (22 pounds) of Cobalt-57, a radioactive metal contained in one of the craft's instruments, pose no danger since all fuel will burn on re-entry some 100 kilometers (330,000 feet) above the ground.

Several attempts to reestablish communication with the spacecraft had failed and this was the first time that Russian space officials acknowledged that the $170 million craft has been lost and will come crashing down.

The failed mission was the latest in a series of recent Russian launch failures that have raised concerns about the condition of the country's space industries.