Efforts to resume contact with a Russian space mission to Mars stuck in Earth orbit after launch have failed and the probe must be considered lost, Interfax news agency reported Saturday.
"All attempts to obtain telemetric information from the Phobos-Grunt probe and activate its command system have failed. The probe must be considered lost," Interfax quoted a source in the Russian space sector as saying.
The source said Russia's space agency would announce the failure of the mission in the next few days.
The space agency had said earlier scientists had a window of only a few days to reprogramme the probe in a bid to send it on its route to Mars. If this does not happen, Phobos-Grunt would fall back to Earth early next month.
The mission went awry after launch Wednesday when the five-billion-ruble ($165 million) probe's engine failed to fire, leaving it orbiting the Earth rather than starting its journey towards the red planet.
The probe had the unprecedented mission to land on the Martian moon Phobos and bring a sample of its rock back to Earth, as well as launch a Chinese Mars satellite.
The mishap caps an inglorious list for Russia's space programme in the 50th anniversary year of Yuri Gagarin's first flight into space.
Three navigation satellites plunged into the sea after a failed launch in December and Russia has since lost new military and telecommunications satellites upon launch.
The accident also comes just days before Russia is due to resume manned space flights to the International Space Station that ground to a halt in August with the crash of a cargo craft.
Explore further: Red moon at night; stargazer's delight