China is about to launch a trio of spacecraft to Mars — including a rover
Early on July 23rd, China is slated to launch its most ambitious space mission yet, sending a trio of spacecraft to Mars — including a rover to explore the planet’s surface. If successful, China will become the second nation to land and operate a rover on the Red Planet.
The mission is named Tianwen-1 — after the long poem “Tianwen,” which means “Questions to Heaven” — and it entails sending an orbiter, a lander, and a rover to Mars. The three spacecraft will launch on top of one of China’s most powerful rockets, the Long March 5, and then travel through deep space together to the Red Planet. While the orbiter studies Mars from above, the lander and rover will make the daring plunge to the surface. The lander is tasked with touching down gently on the ground in one piece, keeping the rover safe and providing a platform for the wheeled vehicle to roll out and explore.
Tianwen-1 is the latest in a long line of increasingly complex space projects that China has tackled over the last decade. The country became the first nation in history to land and operate a rover on the far side of the Moon last year. China remains focused on lunar exploration, with plans to launch a mission at the end of this year to bring back samples from the lunar surface.
Now, with Tianwen-1, China is embarking on what could be its first big interplanetary mission. It has even bolder projects planned for the future, such as visiting an asteroid and visiting Jupiter in the 2030s. “They’re definitely on a long-term quest for lunar and planetary Solar System exploration,” James Head, a planetary geoscientist at Brown University who has worked with scientists in the Chinese Space Program, tells The Verge.
Of course, Mars missions are no easy feat, and China’s first attempt to reach the Red Planet didn’t even make it beyond Earth. In 2011, the country attempted to send an orbiter to Mars called Yinghuo-1, piggybacking on a much larger Russian spacecraft bound for the planet called Phobos-Grunt. But the launch of the vehicle on a Ukrainian rocket ultimately failed, destroying Phobos-Grunt and the Chinese spacecraft.
China is handling both the launch and the spacecraft development for Tianwen-1. If the ambitious mission succeeds, China will become one of only a handful of countries to reach and orbit Mars. China’s goal of landing on the Red Planet during this trip is an even bigger move. Only the United States and the Soviet Union have ever landed on Mars, and only the US has successfully operated a rover on the planet. “It will demonstrate that China is a full-spectrum space power,” David Burbach, a professor at the Naval War College who studies China’s space program, tells The Verge, speaking in a personal capacity. “That they’re able to check all the boxes of what a major space power is able to do.”
As is the case with most Chinese missions, details surrounding this launch are relatively scarce. But China has provided some general information about the overall structure of the mission. The three spacecraft will spend about seven months journeying to Mars, reaching the planet sometime in February 2021. That month will also mark the arrival of the United Arab Emirates’ Mars orbiter, which launched on July 19th, as well as the arrival of NASA’s new Perseverance rover, which is set to launch on July 30th.
Once Tianwen-1 arrives, the trio will stay in orbit for about two to three months, while China surveys their potential landing site. “Basically they want to validate with their own data the characteristics of the site,” says Head, adding, “You build up confidence every day that you’re in Martian orbit until you reach a decision about when to proceed down to the surface.” China is aiming to land in an area of Mars known as Utopia Planitia, according to the mission’s chief scientist writing in Nature Astronomy. Utopia Planitia is the same region on Mars where NASA’s Viking 2 lander touched down in 1976.
Tianwen-1’s rover has a long list of scientific tasks ahead of it, including mapping out Martian geography, looking for any water-ice in the Martian soil, measuring the climate of Mars at the surface, and more. The rover is equipped with six instruments, including its most exciting tool, a ground-penetrating radar that may be able to identify different rocks and even search for reservoirs of water-ice underneath the surface.
To get to the surface, the lander and rover pair will perform an audacious seven- to eight-minute descent to the surface of Mars, according to China’s state-run media agency Xinhua News. The process will be similar to how NASA lands its spacecraft on Mars. First, the spacecraft will rely on Mars’ thin atmosphere to cushion their fall, slowing them down substantially after coming out of orbit. They’ll then deploy a parachute for about a minute and a half to slow down even further. Finally, the lander will ignite an onboard engine to hover over the surface for a few moments and then touch down gently.
Confirmation about the landing’s success or failure will likely rely on official word from China. “They make a very big deal when things succeed; they’re relatively quiet until it’s clear that they’ve succeeded,” says Burbach. “If it goes into orbit, they’ll make a big deal about that. If the landing is successful, I’m sure there will be a lot of attention to that.” As for the orbiter, it will serve as a relay, providing communications between Earth and the rover. It’ll also attempt to survey Mars from above with seven of its own instruments.
But first, the mission has to launch successfully. Airspace closures over the launch site at Wenchang Spacecraft Launch Site in southern China indicate the launch could occur around 12:45AM ET on July 23rd, according to Andrew Jones, a freelance journalist covering China’s spaceflight program. If the launch on the 23rd gets scrubbed, China will have until early August to try again. This launch will be just the fourth launch of the Long March 5, and its track record hasn’t been perfect. While its debut flight went relatively well in 2016, the second launch of the Long March 5 in 2017 ended in failure. China spent up to two years diagnosing the problem and redesigning the machinery in the engines responsible for the failure. Fortunately, the vehicle returned to flight successfully in 2019. If that launch had failed, it’s doubtful Tianwen-1 would have been able to go up this summer.
“This new rocket was designed to take them to the next level,” Jones tells The Verge. “So they’ll be able to launch a space station, carry out a lunar sample return mission and start sending missions to the [lunar] South Pole.” Jones added: “If this launch had failed, they would have a lot of explaining to do as to why basically all these big ambitious space missions which were planned would be delayed again.”
A successful mission would certainly bring even more prestige — and more attention — to China’s blossoming space program. In the US, it will likely renew heated discussions among lawmakers and space policy experts about China’s growing dominance in the space world. However, Burbach says a mission based on science should not be of concern to the US. “If you find a Chinese mission to Mars worrying, it means that you find it worrying that China is a competent science and engineering country, with a capable rocket program overall,” he says. He notes that China has done missions in space that have been cause for concern — such as conducting a test in 2007 to destroy a satellite, creating hundreds of pieces of debris. But a science mission is not something he worries about. “If anything I think it’s an opportunity to allow some additional cooperation with the Chinese technical community,” says Burbach.
While Tianwen-1 could further elevate China on the global stage, the country also sees these missions as a way to inspire youth in the country, according to Jones. “Engaging in these kinds of really challenging high technology areas is something which boosts the economy,” he says. “It also inspires people, just like with the Apollo missions, to get involved in STEM and to pursue these kinds of these kinds of careers that can lead into exploration and all kinds of areas of science and technology.”
Hopefully, if these spacecraft do succeed, we’ll also have a little more insight into Mars. “Every time we go to a different place on Mars we learn something completely new,” says Head. “That’s why it’s so important to have abundant surface exploration and rovers. It just provides a new area; it will be entirely new things, no doubt. And that will complement our overall picture of Mars.”
https://www.theverge.com/2020/7/22/21330251/china-tianwen-1-mars-mission-rover-lander-orbiter-long-march-5-launch