Russia has launched a risky bid to scoop up rock and dust samples from the Martian moon Phobos and bring them back to Earth for study.
The dusty debris should provide fresh insights into the origin of the 27km-wide moon that many scientists suspect may actually be a captured asteroid.
The mission is called Phobos-Grunt - "grunt" means "soil" in Russian.
Shortly after taking off however, there were reports that the spacecraft had veered off course. The Russian space agency said an engine designed to keep the probe on track failed to start, according to Russia's Interfax news agency.
But there are hopes the rocket can still be brought back on course. The venture is also significant because it is carrying China's first Mars satellite.Yinghuo-1 is a 115kg probe that will ride piggyback and be released into an observation orbit around the Red Planet.