The Mars exploration mission will be another milestone for China's deep-space project, after its lunar orbiter and lander programs. But Zhang Rongqiao, the chief architect of the mission, says it will be a very challenging one.

While China has come a long way, it's still relatively new to Mars exploration.

Over the past five decades, there have been as many as 43 exploration missions to Mars, conducted by the United States, Russia, India, Japan and the European Space Agency. However, only the US managed to both orbit and land on the Red planet -- a task China aims to achieve on its first go.

"Through years of analysis of Mars exploration, and taking into consideration our current technology and the international trends, we've decided to divide our mission into two steps. Step one is to orbit Mars. Step two is to bring back samples. That will be accomplished in 2030," Zhang said.

However, the window for a launch is a small one, because both the Earth and Mars orbit the sun.

"We can not postpone it. You only get one chance every 26 months. If you delay, you have to wait another two years. Now we plan to launch in July or August, 2020. Only four years from now. We have a very tight schedule," Zhang said.

However, the chief designer is happy with the mission's progress to date.

"The Mars voyager entered the stage of finalizing its layout planning in September, 2014. After 20 months of theoretical expounding and experimenting, the layout plan has moved into the stage of finalizing the prototype, through separate production and manufacturing units, and testing. This stage lasts about two years. Judging by its progress, the engineering of the Mars voyager is moving relatively smoothly against various difficulties," Zhang said.

The mission will be China's boldest and most challenging attempt in space exploration to date.