Japanese probe fails to land on asteroid

An unmanned Japanese space probe, on a mission to bring back the world's first rock samples from an asteroid, failed to land on its target on Sunday.

Japanese scientists said the Hayabusa descended to within 23 metres of the asteroid Itokawa, located about 290 million kilometres from Earth.

Officials from the Japan Aerospace Exploration Agency (JAXA) said they then lost contact with the probe for several hours and didn't think it completed its mission.

They later re-established contact but said they weren't sure what went awry and were still analyzing information sent by the probe to ground control.

The Hayabusa's navigational system was programmed to abort in a number of different conditions that might endanger the probe, the scientists said.

The Hayabusa which is Japanese for "falcon" was supposed to land briefly, shoot a metal pellet into the asteroid's surface and collect a sample of the material that was stirred up.

Scientists wanted to study its makeup because asteroids are thought to contain rocks that haven't changed for billions of years. They hope to find clues to the solar system's origin.

Japanese space officials are under pressure to produce results from the probe, especially after China recently successfully launched its second spacecraft carrying people.

Mission leader Junichiro Kawaguchi told a news conference in Tokyo that his team may try a second descent on Friday.

The 500-kilogram probe has already sent back numerous detailed photographs of the asteroid.

It was launched in May of 2003 and is expected to return to Earth in June 2007.