Ouyang Ziyuan's interest in the moon first came when he read about the catastrophic collisions when meteorites hit the Earth.

In the most famous collision some 60 million years ago, a meteorite hit the Earth causing a thick fog that obscured the sun. As a result, plants rapidly decayed, and dinosaurs that roamed the Earth ran out of food.

This is the most common explanation among the scientific community for the extinction of dinosaurs, although there are a number of other theories.

"Unlike other celestial bodies, the moon clearly shows thousands of craters. Observing and carefully studying the craters helps us better understand how we on Earth can escape this sort of disaster," said Ouyang, an academician of the Chinese Academy of Sciences (CAS), at a special lecture given to the 36th Scientific Assembly of COSPAR (Committee on Space Research), held in Beijing between July 16 and 23.

Since the late 1990s, Ouyang has been repeatedly lobbying the government to begin lunar exploration. The dream came true in 2004, when the Chinese Government announced a 1.4-billion-yuan (US$175 million), satellite-based lunar exploration programme called the Chang'e Project. Ouyang became the chief scientist for the programme.

As well as the pure scientific value, moon exploration could bring huge economic returns, Ouyang said.

It has huge reserves of metals such as iron. "Given the high costs of exploration, we may not be able to tap the moon through mines like on Earth, but it is worth trying, hopefully in the coming half century," Ouyang said.

Helium-3, an isotope of the element Helium, is an ideal fuel for nuclear fusion power, the next generation of nuclear power. Nuclear fusion creates four times as much energy as nuclear fission, the current form of commercialized nuclear power. Nuclear fusion does not produce environmental problems like radioactive nuclear waste.

"Currently nuclear fusion technology is not mature, but once it is commercialized, fuel supply will become a problem," Ouyang added.

It is estimated that reserves of Helium-3 across the Earth amount to just 15 tons, while 100 tons of Helium-3 will be needed each year if nuclear fusion technology is applied to meet global energy demands.

The moon on the other hand has reserves estimated at between 1 to 5 million tons.

"Each year three space shuttle missions could bring enough fuel for all human beings across the world," said Ouyang.

Compared with the huge potential benefits, China's 1.4 billion yuan (US$175 million) investment is quite low. The same amount of money builds 3 kilometers of subway in Beijing.

"However, we are maximizing every yuan to optimize public money," Ouyang said.

Mission possible

According to Ouyang, China's moon exploration will consist of three stages. In April 2007, a probe satellite Chang'e-I will lift off from Xichang Satellite Launch Centre in southwest China's Sichuan Province.

This mission will be followed by the landing of an unmanned vehicle on the moon around 2011, while in 2017 an unmanned mission will collect samples of lunar soil.

At the moment there is no clear timetable for a manned mission.

China, India and Japan have very similar timetables for their moon projects. The newly launched US moon landing project, with a set goal to send astronauts to the moon between 2015 and 2020, has adopted the same order as China's.

"This indicates we have very similar ideas on what should be done," Ouyang said.

Chang'e-I will orbit the moon for one year and its objectives are to sketch a three-dimensional lunar map, analyze 14 mineral elements in moon craters, measure the lunar surface by microwave radiation technology, and probe the environment difference between the Earth and the moon,

He admitted, however, that it is unrealistic to imagine China's first lunar probe will be totally innovative and surpass the earlier US and former Soviet Union's attempts in all aspects.

The current analysis of minerals in moon craters covers 5 elements, and we will try to improve the number to 14, Ouyang said.

"For the third target, our focus is to improve our understanding of Helium-3 reserves. The current estimate is between 1 million and 5 million tons, and we will try to improve a little, to see whether we can reduce the range, say, to between 1 million and 3 million," Ouyang said.

The chief lunar exploration scientist said international co-operation is essential.

"Due to the movement of the satellite, China's radars can get signals and data for no more than eight hours per day, so we will seek the assistance of international partners," said Ouyang.

He added China has already worked closely with Russia in the fields of space instruments, facilities and observation and control of spacecraft, and with the European Space Agency (ESA) in the fields of observation and control technologies.

According to Ouyang, Michael Griffin, head of the US National Aeronautics and Space Administration (NASA), will visit China in September to discuss concrete co-operation between the two countries in space technologies.

Some US space scientists have said the US should work together with China to explore the moon and deep space, said Ouyang.

"Our research data will be accessible to the world scientific community to enhance the global understanding of the moon," he promised.

Challenges remain

Ouyang said Chinese scientists and engineers have overcome many difficulties in the lunar project.

One engineering problem is how to always keep the solar energy battery of Chang'e-I facing the sun, its detection panel facing the moon and its antenna facing the Earth.

"This difficulty has troubled us for several months, but now we have solved it thanks to a new material," Ouyang revealed.

He said that launch time also used to be a big challenge. Due to the constant motion of the earth and the moon, there are only 35 minutes available in a month for launching a satellite into a lunar orbit.

"But if there is bad weather, we have to delay for one month," Ouyang said.

This has all changed as scientists have designed a new launch: The satellite will first stay in the Earth's orbit for up to two days before it switches into a lunar orbit, providing much greater flexibility.

Challenges also exist in the management and application of the project.

Zhang Shuangnan, a leading astrophysicist at Tsinghua University, said China's space programmes should ensure that all research institutes compete equally and fairly for research projects to improve efficiency and lower costs.

"China's space programmes used to be dominated by its space industry, and the participation of pure academic institutions like Tsinghua was very limited. In the future, the dominance must be broken," Zhang told China Daily.

Robert Nelson, a senior research scientist at NASA, said that due to a space programme's innate nature of concentrating all resources into just a few research teams, sharing data and research results among the scientific community has always been a challenge.

Responding to China Daily's concern, Ouyang said the lunar project considered these problems from the very beginning.

The project will set up a scientific committee consisting of up to 100 universities and institutes - including three in the Hong Kong Special Administrative Region and two in the Macao Special Administrative Region which have the capacity to perform research.

"Each university and institute can only have one delegate on the commission to avoid monopoly," said Ouyang.

"The committee will meet in September for the first time to decide the distribution of research and data across the scientific community. In this way we can ensure the wide participation in the research," he added.

(China Daily July 26, 2006)