Hayabusa2 is now scheduled to blast off aboard Japan's main H-IIA rocket from Tanegashima Space Center in southern Japan at 1:22 pm (0422 GMT), the Japan Aerospace Exploration Agency said Saturday.
The agency had originally planned to launch the rocket on Sunday only weeks after a European spacecraft's historic landing on a comet captivated the world's attention.
But a forecast of thick cloud over the weekend forced the agency to delay the launch.
The 31 billion yen ($260 million) project is sending a probe towards the unpoetically-named 1999 JU3 asteroid in deep space.
It will blast a crater in the asteroid to collect virgin materials unexposed to millennia of solar wind and radiation, in the hope of answering some fundamental questions about life and the universe.