Tianwen-1 Closes In on Mars Orbit
Hundreds of millions of kilometers from Beijing, China’s first stand-alone interplanetary spacecraft is on track to enter the Martian orbit on Wednesday, ahead of a planned touchdown on the red planet later this year.
It has been nearly seven months since a rocket carrying the Tianwen-1 — a combined orbiter, lander, and rover — blasted off in July from the Wenchang Spacecraft Launch Site on the southern island province of Hainan.
The plan is for the craft to orbit Mars for three months before releasing the lander to descend to the surface, according to Wu Yanhua, deputy director of the China National Space Administration.
Tianwen-1 aims to research Mars’ climate, geology, and chemistry — and look for signs of otherworldly life. The craft had traveled over 465 million kilometers as of Friday night, when it sent its first satellite image of Mars back to Earth, according to China Aerospace Science and Technology Corporation, the main contractor for the country’s space programs.
Tianwen-1, whose name means “heavenly questions” and references a classical Chinese poem, is the country’s first solo Mars mission. The expedition also marks the latest development in the nation’s growing space program, which has transformed from a lightweight player into an elite spacefarer in a field historically dominated by the U.S. and the Soviet Union.
It’s not the only nation sending probes to Mars at present, nor the only upstart. The United Arab Emirates launched the first interplanetary mission in the Middle East from a space center in Japan days before Tianwen-1 on July 19. A week later, NASA bade bon voyage to the rover Perseverance, designed to scour the planet’s surface for signs of life after a projected Feb. 18 landing.
If the $8 billion mission is successful, Beijing will become the third global power to boast a Mars landing, nearly half a century after Washington and Moscow.
The question of who actually reached Mars first has been controversial. The Soviet Mars 2 and Mars 3 probes were the first to contact the Martian surface in 1971, but the first crashed on impact and the second failed after about 20 seconds. In 1976, NASA’s Viking Project, which included two pairs of orbiters and landers, became the world’s first successful lander program, beaming data back to Earth for years afterward.
But unlike both of those nations, whose forays evolved from early failures and fly-by probes to landings and trundling rovers, China will seek to condense all of these steps into a single mission. No nation before has combined a maiden solo trip to Mars with its first orbit, its first landing on the planet, and its first roving mission.
The Tianwen-1 mission is the latest in a bevy of attention-grabbing Chinese space expeditions, including the trailblazing Chang’e-4 spacecraft, which achieved a soft landing on the far side of the moon and sent out a rover to gather data and relay it back to Earth via satellite.
But it remains to be seen whether Tianwen-1 can replicate this success, as Mars landings fail more than half the time, according to astronomer Daniel Brown.
The Yinghuo-1 would have been the first Chinese spacecraft to orbit Mars, but its launch aboard a Russian rocket in late 2011 was unsuccessful, and both spacecraft disintegrated in January 2012 after failing to clear Earth’s orbit.
For Tianwen-1, the final and riskiest part of the mission — dubbed the “seven minutes of fear” by Chinese scientists — will come when the lander detaches from the orbiter. The orbiter will then move into another orbit above Mars and relay information back to Earth.
Meanwhile, the lander will plunge into the Martian atmosphere at 4.8 kilometers per second (10,737 mph) and try to withstand temperatures of thousands of degrees Celsius as it plummets toward the surface, one of the probe’s chief designers, Zhang Rongqiao, said in a July interview with state broadcaster CCTV.
The lander will deploy parachutes and reverse thruster engines to slow its descent and cushion the final impact. If everything goes to plan, it will release a golf cart-like rover to roam the Martian surface. The six-wheeled rover is equipped with large solar panels, cameras, and advanced radar that it will use to search for underground water deposits.
This is an original article written by Anniek Bao and Flynn Murphy of Caixin Global, and has been republished with permission. The article can be found on Caixin’s website here.
(Header image: A photo of Mars captured by the Tianwen-1 probe, released by the China National Space Administration, Feb. 5, 2021. People Visual)