China's Mars plan

Like many space-faring nations, China has seen Mars as the next destination ever since it landed on the moon. China plans to orbit Mars, land and deploy a rover, all in one mission around 2021.

No country has tried such a complex mission before, said Sun Zezhou, the chief designer of Mars probe. The United States, which has done most to explore the planet, required two separate missions before landing.

The probe will include an orbiter, a lander and a rover. After an interplanetary journey of 6 to 12 months, the probe will be positioned in orbit. The lander will then be separated, land on the surface and the rover begin its tour, while the orbiter surveys from above.

"All in one mission -- that's quite a bold attempt," Sun said after explaining the process.

BOLD ATTEMPT

The greatest challenge lies in the landing process, given that the weather on Mars is hard to predict, Sun said. "If we encountering a dust storm, the worst possible scenario, the rover can't touch down."

"Besides, the environment on Mars is so special that it is difficult for us to imitate on Earth, which makes it hard to practice," Sun said.

Mars is at least 55 million kilometers from Earth, which makes communicating with the probe another great challenge. One-way transmissions between Mars and the Earth could take as long as 20 minutes, so most of the time the rover will have to deal with things on its own. It must be smart enough to react to whatever it meets, Sun said.

ON JADE RABBIT'S SHOULDER

"We have less than five years till the launch, but we are confident. The probe is being developed by the team that completed the Chang'e-3 lunar probe," said Ye Peijian, of the Chinese Academy of Sciences.

"The successful lunar landing laid the foundation for Mars exploration," said Sun, the chief designer of Chang'e-3 that went to the moon at the end of 2013. "It's on the moon's shoulder that we set have our mission objectives at such high level."

ONE STEP AT A TIME

Reaching Mars is so complicated that few countries have attempted it, and even fewer have made it. Among more than 40 missions since the 1960s, about half failed.

China made one unsuccessful attempt in 2011 when a probe carried by a Russian rocket failed to complete the mission. Calls for speeding up China's own mission mounted after India reached the planet in 2014.

"Although we are not the first Asian nation to send a probe to Mars, we want to start at a higher level," said Ye. "It is only when China gets to Mars that we really enter the age of deep-space exploration,"

According to Sun, the mission will focus on exploring planet's overall environment.

"One step at a time," he said. "Complicated objectives like looking for extra-terrestrial life are not included in our plans this time."

Sun also gave a clue to the specific landing place. "Considering all factors including land forms, light, temperature etc., the latitude of the best landing place ranges from 5 NL to 30 NL," he said.

"As China continues further and further into deep space, it will play a bigger role in solving key frontier scientific questions," Sun added.

Source: XINHUA