China has sent astronauts into space. His robotic probes were on the moon and back. On Saturday (it will still be Friday in the United States) it will attempt to land on Mars, a difficult operation that has resulted in fiery failure many times for space programs that have tried.

With the arrival of Mars and the planet’s orbit in February, the country’s space program confirmed its place among the leading agencies exploring the solar system. But landing on the red planet is in a class of its own. If China succeeds in orbiting, landing and deploying a rover to Mars in a single mission, it will be an unusual achievement in the history of space travel.

The Chinese space agency announced a possible landing date in “early morning May 15,” Beijing time. This would happen in the early evening hours of May 14th.

The announcement also said the attempted landing could still take place on May 19, suggesting there are backup options in case something prevents the trip to the surface on Saturday.

The country’s state media services have not yet announced live coverage of the mission’s attempt to land. They recently started delivering more timely video of China’s space activity, such as live streams of the rocket launch that put a piece of the country’s space station into orbit. In addition, China’s space agency released records of its most recent successful robotic moon landing. We’ll be adding links to a stream of live video coverage as one becomes available.

The Tianwen-1 mission launched from Earth last July and aimed to use the time window every two years when Mars and Earth are closest together on their journeys around the Sun.

The mission consists of an orbiter, a lander and a rover.

The Tianwen-1 orbiter entered Mars orbit on February 10th. Since then he has been circling at a safe distance and preparing for the attempt to land.

The unnamed landing craft carries a rover named after a fire god Zhurong in Chinese folk tales. That name knocked out nine other semi-finalists announced in February.

The mass of Zhurong is about 240 kilograms, or about 530 pounds. That’s a bit fiercer than the Spirit and Opportunity rovers NASA landed on Mars in 2004, but only about a quarter of the mass of curiosity and perseverance of the two NASA rovers currently operating on Mars.

It may be days after touchdown that the rover rolls off the lander. Like Spirit and Opportunity, Zhurong is powered by solar panels. For endurance and curiosity, nuclear batteries convert the heat released by the decay of radioactive plutonium into electricity.

The rover’s seven instruments include cameras, ground penetrating radar, magnetic field detector and weather station.

This was not China’s first attempt at a mission to Mars. That was Yinghuo-1, which failed almost 10 years ago, though through no fault of the country’s own. This spaceship burned down in the Earth’s atmosphere when the Russian missile it was traveling on failed in flight.

His destination is Utopia Planitia or “Nowhere Land Plain”, a huge basin in the northern hemisphere that was most likely destroyed by a meteorite impact. The same region was visited by NASA’s Viking 2 lander in 1976.

The plains are part of the northern lowlands of Mars. If there was once abundant water on the red planet a few billion years ago, this region might have been underwater, part of an ocean that covers the upper part of the planet. The Planitia utopia is among the features proposed as two types of coastline that are remnants of such early Martian seas.

Some of the water from this hypothetical ocean could once have seeped underground and is still frozen there today. In 2016, scientists using a radar instrument on NASA’s Mars Reconnaissance Orbiter concluded that there was actually a lot of ice there – as much water as Lake Superior, which stretches over an area larger than New Mexico is.

One goal of the Tianwen-1 mission is to better understand the distribution of ice in this region that future human colonists on Mars could feed on.

In a virtual conference organized on Friday by Weibo, a popular Chinese social media platform, several scientists discussed the reasons for exploring Mars. One said that the evolution of the planet could teach lessons for changes on earth.

“The purpose is to better protect our earth itself,” Jiao Weixin, professor of geophysics at Peking University, told the forum. “I think this is the most basic purpose of our space exploration.”

Landing on the red planet is dangerous – NASA engineers describe it as seven minutes of terror when its rovers, most recently Perseverance, arrive.

Since Tianwen-1 is already in orbit around Mars, its entry speed is not quite as fast as that of Perseverance. Therefore, China’s lander will need a little extra terror to land – nine minutes – the Global Times reported on Friday, citing experts. The probe will also work on its own, as signal transmission between Mars and Earth currently takes 17 minutes and 42 seconds.

Spaceships are descending towards Mars at high speed, and the thin atmosphere is insufficient to slow down the journey to the ground. The shock waves of the air compressed by the speed capsule generate extreme heat that must be absorbed or dissipated. A number of Soviet, NASA and European missions have crashed.

Only NASA has reached the surface of Mars intact more than once. The landings of its largest rovers, Curiosity and Perseverance, have relied on parachutes to slow the spaceship, shields to divert heat from atmospheric friction, and intricate systems known as sky cranes. These were basically rocket-propelled jetpacks that carried the rovers under them and lowered them to the surface with cables before safely flying away from the landing zone.

For the Tianwen mission, a cone-shaped entry capsule will carry the lander and rover through the atmosphere. A heat shield protects the spaceship from overheated gases as it speeds through the atmosphere. Then the friction of the thin Martian air will help slow it down – by about 90 percent, Tan Zhiyun, a designer at the China Academy of Space Technology, told the Global Times, a Communist Party-controlled newspaper.

The heat shield is thrown off at a lower altitude. In the next step, the parachute and the upper nose-shaped part are thrown away. The four-legged lander, which fires a rocket engine, is similar in construction to the Chang’e-3 and Chang’e-4 lunar landers and hovers briefly as it searches for a safe spot and descends for a safe motorized landing.

China is on the other side of the moon with a robotic rover and recently put a large chunk of its next long-term space station into orbit. The country’s space program has many other goals as well. Read more about China’s space exploration plans here:

Claire Fu contributed to the research.