Slated to launch on a Long March 5 rocket from Wenchang, China in July, the Tianwen-1 mission will attempt to deploy an orbiter above Mars, as well as deposit a lander and rover on the Martian surface. Credit: CNSA.

China is poised to launch the world’s first Mars expedition in July that will accomplish three major goals with one probe.

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, reported.

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 will conduct scientific investigations on Martian soil, geological structure, environment, atmosphere and water.

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 report said.

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 report said.

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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, the report said.

According to Space News, the Tianwen-1 orbiter will be equipped with a high-resolution camera comparable to HiRise on board NASA’s Mars Reconnaissance Orbiter.

It also carries a medium-resolution camera, subsurface radar, mineralogy spectrometer, neutral and energetic particle analyzers and a magnetometer. The orbiter will also play a relay role for the mission rover.

The roughly 240-kilogram solar-powered rover is nearly twice the mass of China’s Yutu lunar rovers, Space News reported. It will carry a ground-penetrating radar, multispectral camera, a Laser Induced Breakdown Spectroscopy instrument and payloads for detecting the climate and magnetic environment.

The rover has a mission design lifetime of three Earth months. The rover will receive a name through a public vote closer to launch. 

China has outlined two landing areas, with a candidate landing site in Utopia Planitia. The landing ellipse is understood to be around 100 x 40 kilometers, Space News reported.

Site selection was driven by a range of factors including flight system engineering constraints and the challenges of entry, descent and landing (EDL) on the Red Planet, and the science goals of the mission.

The Tianwen-1 spacecraft is expected to reach Mars around February 2021. However, the rover landing attempt may not take place immediately, Space News reported.

There are suggestions that the landing segment of the mission will be conducted months later, in April. This would allow mapping and observation of the landing site, despite the availability of high-resolution NASA imagery from HiRise.