what it was and he has not heard it since returning

The sound of a 'hammer hitting an iron bucket' left China's first astronaut feeling nervous and worried during his maiden voyage into space.

Astronaut Yang Liwei made the revelations in a recent interview while talking about the strange noises while aboard the Shenzhen 5 spaceship during a 21 hour mission in 2003.

Although Liwei said he didn't hear the mysterious sound after returning to Earth, other astronauts aboard the Shenzhou 6 and Shenzhou 7 have also reported hearing a similar, if not the same, banging.

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The sound of a 'hammer hitting an iron bucket' left China's first astronaut feeling nervous and worried during his maiden voyage into space. Yang Liwei (pictured) said he heard strange noises while aboard the Shenzhen 5 spaceship during his 21 hour mission in 2003

Liwei manned the Shenzhou 5 on October 16, 2003 and stepped out of the re-entry module during the a 21-hour mission and into the last frontier – making him the 241st human in space.

And although he should be celebrating this honor, Liwei is still haunted by what he heard aboard the vessel.

'A non-causalsituation I have met in space is a knock that appeared from time to time,' he told Xinhua recalling the experience.

'It neither came from outside nor inside the spaceship, but sounded like someone is knocking the body of the spaceship just as knocking an iron bucket with a wooden hammer'.

CHINA'S PLANS FOR ITS OWN SPACE STATION China could start building its space station starting as early as next year, Xinhua quoted Zhou Jianping, chief engineer of the manned spaceflight program, as saying. 'Once the lab mission comes to an end, China will start building our own space station,' Zhou was quoted as saying. The station would be more economically efficient than the International Space Station and use 'more data', he said. China will launch a 'core module' for the station some time around 2018, a senior official said in April, part of a plan for a permanent manned space station in service around 2022. China was prevented from participating in the International Space Station, mainly due to US concerns over the security risks of involving the increasingly assertive Chinese military in the multinational effort. Advertisement

Liwei (pictured) moved around the ship and closer to the porthole to see if he could find its origin. But nothing seemed to be out of the ordinary inside and outside of the craft. Those aboard the Shenzhou 6 and Shenzhou 7 have also reported hearing a strange banging noise

The sound made Liwei very nervous, but he moved around the ship and closer to the porthole to see if he could find its origin.

But nothing seemed to be out of the ordinary inside and outside of the craft.

Following the 21 hour flight, Liwei returned home and tried to mimic the noises he heard with instruments - hoping the space agency's technicians could solve the puzzle.

However, no one has yet to determine what could have caused such a noise and Liwei has not heard it since returning to Earth.

Those aboard the Shenzhou 6 and Shenzhou 7 have also reported hearing a strange banging noise.

Liwei manned the Shenzhou 5 on October 16, 2003 (pictured) and stepped out of the re-entry module during the a 21-hour mission and into the last frontier – making him the 241st human in space

Liwie said,'Before entering space, I have told them that the sound is a normal phenomenon, so there is no need to worry.'

Liwei was born in Liaoning province's Suizhong County in 1965, became the first person sent into space by the Chinese space program in 2003.

This year China has been firmly establishing its place in the space race, by unveiling the world's largest radio telescope, launching a space lab in preparation for a space station and unveiling plans to send a mission to Mars.

In October, the Asian country announced that they have plans for a new space plane that could fly up to 20 passengers to the edge of space each day.

China's plane would be a vertical take-off and landing aircraft, the magazine reported. The researchers presented two ideas.

The first design weighs in at 10 tonnes and has a wingspan of 19.6 feet (6 meters).

This year, China has been firmly establishing its place in the space race. Now it seems the country also has its eyes on commercial spaceflight. Designs of a new space plane that could fly up to 20 passengers to the edge of space each day, have been revealed (pictured)

This smaller version should be able to fly five people to an altitude of 62 miles (100 km), where space officially begins, letting passengers experience two minutes of weightlessness.

The second design was for a scaled up 100-tonne version, with a 40 foot (12 meter) wingspan, could fly 20 people to 80 miles (130 km), giving four minutes of weightlessness.

A ride in this space plane is expected to