|Organization||China National Space Administration (CNSA)|
|Purpose||Robotic Interplanetary mission|
|First flight||Tianwen-1, July 23, 2020, 04:41 UTC|
|Last flight||Tianwen-1, July 23, 2020, 04:41UTC|
|Launch site(s)||Wenchang Spacecraft Launch Site|
|Launch vehicle(s)||Long March rockets|
The Planetary Exploration of China (PEC; Chinese: 中国行星探测; pinyin: Zhōngguó Xíngxīng Tàncè), also known as Tianwen (Chinese: 天问; pinyin: Tīanwèn; lit. 'Questions to Heaven'), is the robotic interplanetary spaceflight program conducted by the China National Space Administration (CNSA). The program aims to explore planets of the Solar System, starting from Mars, and will be expanded to Jupiter and more in the future.
The program was initially known as the Mars mission of China at the early stage. It was later announced as Planetary Exploration of China in April 2020. The series of missions was named Tianwen.
The first mission of the program, Tianwen-1 Mars exploration mission, began on July 23, 2020. A spacecraft, which consisted of an orbiter, a lander, and a rover, was launched by a Long March 5 rocket from Wenchang. The Tianwen-1 was inserted into Mars orbit in February 2021 after a seven-month journey, followed by a successful soft landing of the lander and Zhurong rover on May 14, 2021, making China the second country in the world who successfully soft-landed a fully operational spacecraft on Mars surface after the United States.
China began its first interplanetary exploration attempt in 2011 by sending Yinghuo-1, a Mars orbiter, in a joint mission with Russia. Yet it failed to leave Earth orbit due to the failure of Russian launch vehicle.
On December 13, 2012, the Chinese lunar probe Chang'e 2 made a flyby of the asteroid 4179 Toutatis in an extended mission. With a distance of over 7 million kilometers away from Earth, Chang'e 2 became China's first interplanetary probe which tested the limit of China's deep space communication capability.
On November 14, 2019, CNSA invited some foreign embassies and international organizations to witness hovering and obstacle avoidance test for Mars Lander of China's first Mars exploration mission at the extraterrestrial celestial landing test site. It was the first public appearance of China's Mars exploration mission.
On April 24, 2020, Planetary Exploration of China was formally announced by CNSA, along with the name "Tianwen" and emblem of the program. The first mission of the program, the Mars mission to be carried out in 2020, was named Tianwen-1.
The first mission of the program, Tianwen-1 Mars exploration mission, was launched on July 23, 2020. The Tianwen-1 was inserted into Mars orbit in February 2021 after a seven-month journey, followed by a successful soft landing of the lander and Zhurong rover on May 14, 2021. The Zhurong rover was deployed onto the Martian surface from its landing platform and began its exploratory mission on May 22. On June 1, CNSA released multiple high-resolution images taken on Martian surface, confirming the success of the mission.
On June 12, 2021, CNSA announced the future plans for near-Earth asteroid sample return, Mars sample return and Jupiter system exploration.
The program's name "Tianwen", which literally means "questions to heaven", derived from the eponymous poem by the famous ancient poet Qu Yuan of the state of Chu during the Warring States period (475–221 BC). The name represents the Chinese people's relentless pursuit of truth, the country's cultural inheritance of its understanding of nature and universe, as well as the unending explorations in science and technology.
The emblem of PEC and its missions consist of eight planets in the Solar System and their orbits in the shape of the Latin letter 'c', referring to China, cooperation, and the cosmic velocity required to undertake planetary exploration.
Wenchang Spacecraft Launch Site is China's newest space vehicle launch facility. It is the only launch site in China capable of launching China's most powerful rocket Long March 5, which offers the maximum payload capacity into deep space.
Tianwen-1, the first mission of PEC, was launched from Wenchang.
The facility consists of six 140-meter tall cranes and one central platform, which is connected with the cranes by 36 cables. The movement of the platform provides simulation of the Mars gravity environment to the lander hung below it. The ground of is paved with special material, which can be manipulated to form the shapes of pits or slopes.
The extraterrestrial celestial landing test site is used to test the lander's capability of hovering, obstacle avoidance and slowing down.
As China's first independent Mars exploration mission, Tianwen-1 set out to accomplish three major goals simultaneously: orbiting, landing on, and roving Mars via a single set of spacecraft. On July 23, 2020, the Tianwen-1 spacecraft stack, consisting of an orbiter, a lander, a rover, a deployable and a remote camera launched from Wenchang, marking the beginning of the mission.
After a 202-day journey through interplanetary space, Tianwen-1 inserted itself into Martian orbit on February 10, 2021, thereby becoming China's first Mars orbiter. During this long journey, it deployed the deployable camera in September 2020 whose imagery confirmed the successful launch and Mars transit phase of the spacecraft. Subsequently, it performed several orbital maneuvers and began surveying target landing sites on Mars in preparation for the coming landing attempt.
On May 14, 2021, the lander and the Zhurong rover separated from Tianwen-1's orbiter. After experiencing Mars atmospheric entry that lasted about nine minutes, the lander and rover made a successful soft landing in the Utopia Planitia region of Mars. With the landing, China became the second country to operate a fully functional spacecraft on Martian surface, after the United States.
On May 22, 2021, the Zhurong rover deployed onto the Martian surface from its landing platform and began its exploratory mission. During its deployment, the Rover's instrument, Mars Climatic Station (MCS), recorded the sound, acting as the second Martian sound instrument to record Martian sounds successfully after Mars 2020 Perseverance rover's microphones. During this journey it deployed the remote selfie camera on 1 June, 2021, whose imagery confirmed the successful landing of the rover and lander.
On December 17, 2020, China successfully completed the Chang'e 5 lunar sample return mission. During the press conference after the mission, Wu Yanhua, the vice administrator of CNSA, disclosed that a Mars sample return mission will be carried out as planned later in the decade.
According to Wang Xiaojun, head of the state-owned China Academy of Launch Vehicle Technology, China plans to send its first crew to Mars and planning base for regular crewed missions, primary launches to Mars are planned for 2033, 2035, 2037, 2041 and will shift to sustaining presence on mars in near future.
China is planning a mission to Jupiter and possibly to the Jovian moon Callisto. One of two possible mission architectures ("Jupiter Callisto Orbiter" and "Jupiter System Observer") would likely be launched in 2029 and arrive at the Jovian system in 2035, after one Venus flyby and two Earth flybys.
|Launch site||Launch vehicle||Spacecraft||Orbital insertion date
|Landing location||Operational time||Status||Notes|
|Tianwen-1||July 23, 2020
|Wenchang||Long March 5||Tianwen-1 orbiter||February 10, 2021
|Tianwen-1 lander||May 14, 2021
||3 hours||Success||No scientific payload on lander. Reaches end of designed lifespan after landing.|
|Zhurong rover||155 days||Operational||Deployed onto the Martian surface on May 22, 2021.|