If it's the moon you want, then Yung's your man

PUBLISHED : Sunday, 29 April, 2012, 12:00am
UPDATED : Sunday, 29 April, 2012, 12:00am

A Chinese soup spoon was enough to get Yung Kai-leung thinking about how to design the perfect space-exploration tool, specifically one for scooping up moon rock.

'Why is a Chinese ceramic spoon so different from a Western metal spoon?' said Yung, with two decades of space engineering under his belt.

'A ceramic spoon is good for drinking soup because the material won't get too hot and is easy to scoop out from a deep bowl. A Western spoon is better for eating out of a flat bowl.' And so it is that one of the sophisticated devices set to be on board an unmanned Chinese rocket due to land in the moon in 2017 was inspired by a Chinese soup spoon.

Still in the prototype stage, its mission is to scoop up stones from the moon's surface into an airtight container to be transported about 380,000 kilometres back to earth.

Professor Yung is the associate head of Hong Kong Polytechnic University's department of industrial and systems engineering. And, following an agreement signed this month, he will be leading the research team to complete the third and final phase of China's first lunar exploration programme, which is all about collecting samples.

The second phase is landing, and will see the rockets Chang'e 3 and 4 - named after China's moon goddess - launched into space next year.

The first phase, which cost 1.4 billion yuan (HK$1.7 billion) alone, involved circling the target and was accomplished by two lunar orbiters - Chang'e 1, which ended its voyage with a controlled crash on the moon in 2009, and Chang'e 2, which left the moon to explore further into space and is currently 1.5 million kilometres above earth.

Yung's sampling device for the Chang'e 5 is attached to a folding four-metre robotic arm and it won't just scratch the surface - it is also capable of digging down two metres.

The professor said a firm grasp of materials was one of the most important skills required of a space engineer.

'When we are in space and not facing the sun, the temperature may drop to minus 180?C. Or the temperature can be as hot as 180?C. Some materials may stick together if it's too cold, and we call this cold welding,' he said.

Yung said the national space programme asked him and colleagues in the city to contribute because 'Hong Kong engineers are highly knowledgeable about materials and are better designers'.

Yung's space tools are manufactured using a combination of titanium alloys, aluminium alloys, ceramics and Teflon, making them light but sturdy.

As to precisely how the device extracts samples, the details will remain under wraps until further announcements from the space authorities.

Yung's team is also involved in the second phase; he developed a panoramic camera fixed to the top of the rocket which will track China's first moon rover as it explores the surface. The vehicle will be controlled back in China and is scheduled to roam the moon for three months, surveying the territory and assessing the atmosphere.

A flight model of the camera is undergoing simulation tests which involve it being pounded by radiation, electric shocks, vibration and dust.

'Foreign countries may have started lunar expeditions in the '50s and '60s, but the machinery we have developed now has made huge strides and is completely new,' said Yung.

Yung is a product of the Hong Kong Technical School, which later became PolyU. His career as a designer of precision instruments for space exploration began in 1995, when he helped create forceps - invented by dentist Dr Ng Tze-chuen - to pick up samples on planet surfaces. Ng had originally intended the forceps for dental surgery. The device was later used by Russian astronauts at the MIR space station.

In 2003, he helped develop a rock corer for Mars. It was on board the Beagle 2 Lander for the European Space Agency's ill-fated Mars Express Mission, with which mission control engineers lost contact six days before it was to enter the red planet's atmosphere.

Yung worked with the Russians again on a mission to collect, grind and sift soil from Phobos, the largest moon of Mars. However, the Russian spacecraft only reached 345 kilometres into the atmosphere before falling back to earth.

Yung is involved in another Russian mission, this time to the planet Venus - where temperatures can reach up to 450 degrees Celsius. A spacecraft is also due for lift-off in 2017.

Precision is the key to designing space tools, says Yung. Every detail has to be considered, and they must be flawless. 'Take the lubricant we use in the machinery, for example. It's a complicated science,' Yung said. 'We have to find out if the lubricant will have a chemical reaction to titanium or other materials at certain temperatures.'

The best lesson that Ng can give to budding engineers is to be observant. 'Engineering surrounds your daily life. Take examples of good design and add it to your own. Build on great things that have been done before,' Ng said.

That's something to think about over your next bowl of soup.


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