A Japanese spacecraft rocketed toward Mars on Tuesday on an unprecedented quest to explore its mysterious moons and bring back samples.

Five of the world's space agencies joined forces for the five-year mission that will attempt to land a robotic prospector plus a rover on Phobos, the larger and closer of Mars' two pint-sized moons.

The Japan Aerospace Exploration Agency, which is leading the bold sampling effort, launched the spacecraft before dawn from the country's main spaceport on Tanegashima Island.