Tianwen 1 Mars mission to land soon
Tianwen 1, China’s first independent Mars mission, is set to land its rover on the red planet between Saturday and Wednesday and will deploy a rover on Martian soil in the coming days if everything goes according to plan.
If it touches down safely on the reddish sphere and works as planned, the Tianwen 1 rover, recently named Zhurong after an ancient Chinese god of fire, will be the sixth such vehicle deployed on Mars, following five predecessors launched by the United States. It will also give Chinese scientists their first opportunity to closely observe Mars, which was first recorded in the country on oracle bone inscriptions in about 1300 BC.
The selected landing site for Zhurong is in the southern part of the Utopia Planitia, a large plain within Utopia, the largest known impact basin in the solar system.
The rover is 1.85 meters high and weighs about 240 kilograms. It has six wheels and four solar panels, can move at 200 meters an hour on the Martian surface, and carries six scientific instruments, including a multispectral camera, a meteorological sensor and ground-penetrating radar.
If the semi-autonomous craft functions efficiently, it will work for at least three months and undertake comprehensive surveys of the planet. Its success will mark the completion of all of Tianwen 1’s mission objectives — orbiting Mars for comprehensive observation, landing on the planet and deploying a rover to conduct scientific operations — also making Tianwen 1 the first Mars expedition to accomplish all three goals with one probe.
The Tianwen 1 probe, named after an ancient Chinese poem, was launched by a Long March 5 heavy-lift carrier rocket on July 23 from the Wenchang Space Launch Center in the southernmost island province of Hainan, kicking off China’s planetary exploration program.
Consisting of two major sections — an orbiter and a landing capsule — the spacecraft traveled more than 470 million kilometers before entering a Martian orbit on Feb 10, when it was 193 million km from Earth. Because the two celestial bodies keep moving in their own orbits, a Mars-bound spacecraft must fly in a carefully designed, curved trajectory to catch up with the red planet.
Depending on the two planets’ orbits, the distance between Mars and Earth ranges from 55 million km to 400 million km. The red planet is now about 318 million km from Earth.
On Feb 24, Tianwen 1 entered a preset parking orbit above Mars. The spacecraft was programmed to maintain that orbit for about three months to examine the preset landing site before releasing its landing capsule to descend through the Martian atmosphere and touch down on the surface.
Up in the Martian skies, the orbiter will continue circling the red sphere for mapping and measurement tasks with seven scientific instruments, including a high-resolution imager and magnetometer. It will also relay signals between ground control and the rover.
Tianwen 1 is the world’s 46th Mars exploration mission since October 1960, when the former Soviet Union launched the first Mars-bound spacecraft. Only 19 of those missions were successful.
Lunar accomplishments
Back in 1970, the year China launched its first satellite into space, some scientists suggested that the government should begin the country’s lunar exploration program.
However, their suggestion was turned down by Premier Zhou Enlai out of considerations of technological, technical and financial difficulties.
In February 2003, the government said it was ready to start a lunar program and appointed three scientists to head the project team.
In January 2004, the first phase of the Chang’e program was officially approved, marking the formal opening of China’s lunar exploration mission.
After nearly four years of preparations, the first spacecraft stemming from the program — Chang’e 1 — was launched on Oct 24, 2007, from the Xichang Satellite Launch Center in Sichuan province. It was tasked with verifying China’s lunar probe technologies, obtaining lunar images and performing scientific surveys.
Since then, the country has made remarkable strides in lunar exploration in an incremental manner.
Chang’e 3, lifted in December 2013, was the first Chinese spacecraft to soft-land on the moon and also the first craft to touch down on lunar soil since the Soviet Union landed its last lunar probe on the moon in August 1976. It released the first Chinese lunar rover, Yutu, on the moon.
Chang’e 4, launched in December 2018, landed on the far side of the moon, becoming the first spacecraft to closely observe the little known “dark side of the moon”. The probe also deployed a rover named Yutu 2.
The most significant event in China’s space field in 2020, and also one of the world’s most notable space activities that year — the Chang’e 5 robotic mission — was launched on Nov 24 at the Wenchang launch center and successfully landed on the moon on Dec 1.
The landmark mission brought 1,731 grams of lunar rocks and soil back to Earth on Dec 17, achieving a historic accomplishment about 44 years after the last lunar substances were brought back from our nearest celestial neighbor.
The 23-day mission made China the third country that has retrieved lunar samples, after the US and the former Soviet Union.
Chang’e 5’s orbiter is now flying around Lagrange Point 1 — which is located between the Earth and the sun and is an ideal position for monitoring solar activities — for extended scientific operations.
China plans to use the Chang’e 6 mission to collect samples from the moon’s south pole or even the celestial body’s far side, space officials have said.