MOSCOW, September 21 (RIA Novosti) - The launch of the Russian mission to one Mars' moons has been delayed until 2011, said Lev Zeleny, chief of the Institute of Space Research at the Russian Academy of Sciences.

"I can officially announce that the Phobos-Grunt mission has been postponed until 2011," he said.

He cited a tight schedule and the final testing of all systems as reasons for the delay. The launch of the mission was initially scheduled for 2009.

Phobos-Grunt is an unmanned lander that will spend several months studying the planet and its moons from orbit before landing on Phobos. Under the new schedule, the return vehicle with soil samples is expected to be back on Earth in 2012.