Scientists across China are pushing forward with a project to send a probe to Mars, possibly in four years, but the research is being done largely out of the public eye.
The technological challenges involved are much greater than those posed by the soft landing of the Chang-e 3’s rover on the moon in December, specialists involved in the programme say.
The environment is more harsh, and communicating with controllers back on earth more complex. But a successful touchdown on the Martian surface would bring China on par with the American leader in space exploration, they say.
One of the specialists involved in the programme is Professor Dong Zhibao, a desert engineering specialist with the Chinese Academy of Sciences. The government asked Dong last year to lead a team of more than a dozen researchers to scout the Tibetan Plateau for areas that could simulate conditions found on Mars.
The goal was to build a research facility where experts could test out how Mars rover technology and equipment reacted to extreme conditions, he said.
“It is a very difficult job. We are required to enter hostile areas probably never visited by a human before,” Dong said. “We are also under time pressure. The study must be concluded before the launch of the first Martian probe, which is likely to be in 2018.”
Dong said the plateau was an ideal stand-in for Mars. “Tibet is very cold, very dry with very low air pressure. It also has very strong winds and frequent dust storms,” Dong said. “Generally speaking, it has a hostile environment more similar to Mars than some famous sites overseas, such as Chile in South America or the Antarctic.
After analysing remote-sensing satellite data about the Tibetan Plateau, Dong’s team pinned down eight possible sites.
“We must visit all of them to obtain first-hand data. Some unmanned stations will be set up to monitor changes to the environment. But getting there is a headache. None of the sites are near any roads, as terrain must be free of any trace of people to ensure the best possible simulation,” Dong said.
The sites’ terrain is uneven and littered with sand and small rocks, ideal for researchers to try out soft landing mechanics, robotic rover manoeuvres and eventually astronaut field training.
But the construction and maintenance cost of Tibetan facility would be steep, requiring new roads, airports and other supporting facilities. “The best location for science often needs the highest budget,” he said.
Although China’s lunar landing went off without a glitch, Mars presents a more complex challenge. The US programme had its first success in 1964, when Mariner 3 carried out a fly-by of the planet and sent back 21 images. Twelve years later, Viking 1 became the first craft from earth to land on the Martian surface.
But more than half of all Mars missions, by the US, the former Soviet Union, Russia and Japan, have failed, including China’s Yinghuo-1 probe, which could not escape the earth’s orbit when a rocket burn on the Russian spacecraft carrying it failed in 2011. It eventually fell back into the atmosphere and disintegrated.
Professor Cao Qixin, a robotics specialist with Fudan University in Shanghai who is helping design a Martian rover, is well aware of the past failures but calls the planet the “ultimate arena for technical competition”.
Cao said his team was working on fundamental design issues, such as wheel design, the automatic navigation system, and energy generation and conservation technology.
“The Mars rovers of the US have taught us some valuable lessons,” Cao said. “We have learned, for instance, the importance of developing technology to counter dust storms as rovers had often lost contact in bad weather,” he said.
The rover would also need a sophisticated navigation system to negotiate the terrain on its own, due to the communication lag the operations team back on earth would face. And in the event of any unforeseen problems, the rover would have to be able to find its way back to the lander in order to re-establish a signal with the team.
Professor Shang Haibin, whose team at the Beijing Institute of Technology is receiving government funding to plot trajectories from the earth to Mars, said one of their main obstacles was a lack of first-hand data on Mars’ gravitational field.
Before any landing mission, China would likely send a probe to orbit the planet to gather crucial information about the strength of the field, he said.
That launch was widely expected to take place in 2018, when the two planets were best aligned for a flight that would require the least amount of energy.
But Shang was optimistic on China’s chances for success. “In some areas, we are already on par with the US. I think it is quite realistic now to think about meeting them on Mars,” he said.
A senior scientist with the China Aerospace Science and Technology Corporation said the government would not officially announce any Mars expedition until much of the programme was well in place.
“China does not want to start a space race with the US as the Soviet Union did. China’s strategy is to catch up quietly,” he said, declining to the named due to the corporation’s media policy.
“If China announced it was going to Mars immediately after the moon landing, the US might feel a threat and increase spending on its space projects.
“If there is a race between China and the US in space, it would be a turtle-rabbit race. The more arrogant the rabbit is, the better for the turtle.”