Japan will send a space probe on a six-year mission to mine a distant asteroid.

The Y31 billion ($A327.2 million) project comes just weeks after a European spacecraft's historic landing on a comet captivated the world's attention.

Hayabusa2 is set to blast off aboard Japan's main H-IIA rocket from Tanegashima Space Centre on Sunday.

It will head towards the unpoetically-named 1999 JU3 asteroid in deep space.

About the size of a domestic fridge, Hayabusa2 is expected to reach the asteroid in mid-2018 and will spend around 18 months studying the surface.

In a galactic first, Hayabusa2 will drop an "impactor" that will explode above the asteroid's surface and fire a metal bullet into the crust at a speed of 7,200 kilometres an hour - six times the speed of sound on Earth.

The bullet is expected to create a small crater that will enable the probe 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.

"The asteroid is carbonaceous and we may find organic matter and water, the stuff of life," Hitoshi Kuninaka, project leader at the Japan Aerospace Exploration Agency (JAXA), said in an interview on the agency's website.

Analysing the extra-terrestrial materials could help shed light on the birth of the solar system 4.6 billion years ago and offer clues about what gave rise to life on Earth, he said.