China’s Mars Mission Begins Orbit of the Red Planet

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China has landed on the moon three times, and even managed to bring one of its robotic lunar explorers back to Earth. Can it now pull off the challenge of landing on Mars?

The country’s space agency completed a key step toward that goal on Wednesday when Tianwen-1, the spacecraft the country launched last July, began its orbit of the red planet, according to state media reports. By accomplishing this feat, China completed its first successful journey to another planet in our solar system.

The spacecraft was also the second to arrive at Mars in two days, following a United Arab Emirates probe that began orbiting the neighboring world on Tuesday.

Tianwen-1 left Earth last summer, taking advantage of a period when Mars and Earth were closest to each other during their journeys around the sun. That allowed a relatively short transit between the two worlds.

To catch up with Mars, the spacecraft fired its engines on several occasions, correcting its course so it could approach the red planet at the correct angle. After the most recent engine firing on Feb. 5, the probe sent back pictures of the red planet from a distance of about 1.3 million miles.

On Wednesday at 7:52 p.m. in Beijing (6:52 a.m. Eastern time), the engine lit up again for 15 minutes, expending much of the spacecraft’s remaining fuel in a braking maneuver. That slowed it considerably, and allowed the probe to be captured by Martian gravity into an elliptical orbit. It will now circle at a safe distance, joining the cast of other robotic explorers in Martian orbit as it prepares for that later surface landing attempt.

In arriving at Mars, China far surpassed its last attempt at an interplanetary mission, which failed nearly 10 years ago, although through no fault of the country’s own. That Mars-bound spacecraft, Yinghuo-1, burned up in Earth’s atmosphere when the Russian rocket it was traveling on failed in flight.

But while the arrival at Mars was a new milestone for China’s space program, a bigger challenge for the Tianwen-1 mission is a few months away.

The orbiter carries a lander and a rover which will make the difficult transit to the surface. China says it will attempt to land on Mars as early as May, but it has not specified a date.

Its destination is Utopia Planitia, a large basin in the northern hemisphere that most likely was once impacted by a meteor, and which was visited by NASA’s Viking 2 lander in 1976. One goal of the Tianwen-1 mission is to better understand the distribution of ice in this region, which future human colonists on Mars could use to sustain themselves.

Landing on the red planet is perilous. Spacecraft descend at a high speed and the thin atmosphere does little to help slow the trip to the ground. Air friction still generates extreme heat that must be absorbed or dissipated. A number of Soviet, NASA and European missions have crashed. Only NASA has landed intact more than once.

The Chinese spacecraft will spend months orbiting Mars to check systems and pick a landing spot that will not be too treacherous.

Should it land in one piece, the rover will need a name. After nominations from people in China, a panel of experts selected 10 semifinalists. Among them, according to state media, are Hongyi, from a Chinese word for ambition and persistence; Qilin, a hoofed creature of Chinese legend; and Nezha, a young deity who is considered a patron of rebellious youth.

Since China launched its mission to Mars in July, it has been to the moon and back.

The Chang’e-5 mission lifted off in November, collected lunar samples and then brought them back to Earth for scientists to study. It was the first new cache of moon rocks since the Soviet Union’s last lunar mission in 1976.

China’s Chang’e-4 mission, the first to land on the moon’s far side, is still in operation and its Yutu-2 rover is still studying the lunar surface more than two years after it launched.

The first robotic probe to arrive at Mars this year was Hope, an orbiter from the United Arab Emirates’ emerging space agency. It arrived on Tuesday, and will embark on a study of the red planet’s atmosphere, helping planetary scientists understand the weather dynamics of Mars.

The third new visitor to Mars will be Perseverance, NASA’s newest rover. It launched a bit later than the other two spacecraft last July, and will skip Martian orbit, heading directly to the planet’s surface on Feb. 18.

The robotic explorer would be NASA’s fifth rover on Mars, and it is very similar to Curiosity, which is now exploring the Gale crater. The new rover carries a different set of scientific instruments and will explore the Jezero crater, a dried-out lake that scientists believe could be a good target to seek fossilized evidence of extinct Martian microbial life.

The mission will also attempt a new first on the red planet: flying a helicopter in the wispy Martian atmosphere. NASA’s Ingenuity helicopter will be dropped off by the rover not long after landing. Then it will attempt a number of test flights in air as thin as the upper reaches of Earth’s atmosphere, aiming to demonstrate that Mars can be explored through the air as well as on the ground.

It’s getting a bit crowded around the red planet.

In addition to the new arrivals, six more orbiters are currently studying the planet from space. Three were sent there by NASA: Mars Odyssey, launched in 2001, Mars Reconnaissance Orbiter, launched in 2005, and MAVEN, which left Earth in 2013.

Europe has two spacecraft in orbit. Its Mars Express orbiter was launched in 2003, and the ExoMars Trace Gas Orbiter lifted off in 2016 and is shared with Russia’s space program.

India operates the sixth spacecraft, the Mars Orbiter Mission, also known as Mangalyaan, which launched in 2013.

Two American missions are currently operating on the ground. Curiosity has been roving since 2012. It is joined by InSight, which has been studying marsquakes and other inner properties of the red planet since 2018. A third American mission, the Opportunity rover, expired in 2019 when a dust storm caused it to lose power.



Source : Nytimes