Digging into China's first moon mission

A Chinese soup spoon inspired Professor Yung Kai-leung to design a robot tool to pick up rocks on the moon.

The device, still in the prototype stage, will be attached to a four-metre-long robotic arm and put on board China's unmanned Chang'e-5 rocket due to land on the moon in 2017.

If all goes to plan, it will scoop up stones from the moon's surface and put them in a container to be sent back to Earth.

Yung is the associate head of Hong Kong Polytechnic University's (PolyU) industrial and systems engineering department. His team has been given the job of collecting rock samples in the final phase of China's first moon exploration programme.

Yung approached the design task by asking himself a simple question: 'Why is a Chinese ceramic spoon so different from a Western metal spoon?'

'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.'

Yung then applied the principles to his design. Space authorities are keeping details of the device under wraps for now.

The professor said a strong understanding of materials was one of the most important skills for a space engineer.

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

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

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

Yung's team is also involved in the landing phase of the project. He has developed a camera that will track China's first moon rover as it explores the surface. The rover will roam the moon for three months.

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

Yung graduated from the Hong Kong Technical School, which later became PolyU.

His started designing precision instruments for space exploration in 1995, when he helped create forceps - invented by dentist Dr Ng Tze-chuen - to pick up samples on planet surfaces.

The device was later used by Russian astronauts at the Mir space station.

In 2003, Ng 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.

Yung worked with the Russians again on a mission to collect, grind and sift soil from Phobos, the largest moon of Mars. But 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 due for lift-off in 2017.

Precision is the key to designing space tools and they must be flawless, Yung said.

'Take the lubricant we use in the machinery, for example. It's a complicated science,' he 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.

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