Mission in July to place rover on Mars' surface

China plans to launch a Long March 5 carrier rocket in July to send a spacecraft toward Mars that will land a rover on the red planet, according to the program's major contractor.

China Aerospace Science and Technology Corp, a State-owned space conglomerate, said in a statement sent to China Daily on Tuesday that the Tianwen 1, or Quest for Heavenly Truth 1, mission will fulfill three scientific objectives-orbiting the red planet for comprehensive observation, landing on the Martian surface and sending a rover to roam the landing site. It will conduct scientific investigations on Martian soil, geological structure, environment, atmosphere and water.

If Tianwen 1 succeeds, the mission will become the world's first Mars expedition accomplishing all three goals with one probe, the company said.

Tianwen is a long poem by famous ancient poet Qu Yuan of the Kingdom of Chu during the Warring States Period (475-221 BC). He is known for his patriotism and contributions to classical poetry and verses, especially through the poems of the Chu Ci anthology, also known as Songs of Chu.

In the mission's first step, a Long March 5, the nation's biggest and most powerful rocket, will blast off at the Wenchang Space Launch Center in Hainan province to transport the robotic probe to the Earth-Mars transfer trajectory before the spacecraft begins its self-propelled flight toward Mars' gravity field.

The farthest distance between the Earth and Mars is about 400 million kilometers while the nearest is 55 million km, depending on their position in orbit. A probe will travel about seven months before reaching Mars' atmosphere.

The space contractor said the probe consists of three parts-an orbiter, lander and rover-and they will separate in Mars' orbit. The orbiter will remain in orbit and the lander-rover combination will make an autonomous descent and landing.

The rover, set to be the world's seventh of its kind and the first from Asia, has six wheels and four solar panels and will carry six scientific instruments. It will weigh over 200 kilograms and work about three months on the planet, according to Sun Zezhou, the probe's chief designer at the China Academy of Space Technology.

Bao Weimin, director of science and technology at China Aerospace Science and Technology Corp and an academician of the Chinese Academy of Sciences, said the biggest challenge will be the descent and landing.

To understand and prepare for those difficulties, engineers carried out a key experiment in November to verify the design and capability of the lander-rover combination. A test model tied to a 140-meter metal tower conducted hovering, descent and obstacle-evading operations in a simulated Martian gravitational environment at Asia's largest test site for extraterrestrial landings.