10pm ET Friday Update: In what can aptly be described as a tremendous success, China has become only the second nation to soft land a spacecraft on the surface of Mars.
— CGTN (@CGTNOfficial) May 15, 2021
Chinese media report that the Zhurong rover is expected to roll off the lander within the next three Martian days to begin its exploration of the red planet.
Original post: As early as Friday evening in the United States, China will attempt to set its Tianwen-1 lander down on the surface of Mars. After weeks of speculation, the China National Space Administration confirmed that the country will seek to land the mission, including its “Zhurong” rover, sometime between 23:00 UTC on Friday, May 14 and May 19.
Named after an ancient fire god in Chinese mythology, the Zhurong rover has a mass of about 240 kg. This means the Chinese rover is comparable in size to the Spirit and Opportunity rovers that NASA landed on Mars in January 2004.
There is a lot of intrigue surrounding the high-risk mission. Before this mission, China had never sent a spacecraft to Mars. In this single spacecraft, the country packed both an orbiter and a modest-sized lander with a rover. Moreover, no country other than the United States has successfully soft-landed a spacecraft on Mars or deployed a rover. Other countries have tried and failed multiple times.
So will China succeed? I’ve informally asked experts in planetary science and missions what the chances of success are for the landing. Most of these sources are based in the United States or Europe, so they don’t have deep insight into China’s space program, at least not deep enough to have a probabilistic risk assessment of the landing attempt.
That said, the consensus among my sources is that the landing probably has slightly better than a 50 percent chance of total success, meaning the lander touches down softly and the Zhurong rover is able to wheel away and do some meaningful science. It is designed for a nominal mission of 90 days, but it may last longer.
The Tianwen-1 spacecraft arrived in orbit on February 10, 2021, and has spent the last three months collecting images of the area where it is due to land, the large Utopia Planitia impact basin. This relatively smooth site in the Martian mid-latitudes is where NASA landed the Viking 2 mission in 1976.
If Zhurong survives the entry through the Martian atmosphere using a combination of parachutes and a powered descent, it will be able to explore an interesting area that may once have been covered by an ocean. The rover will study the soil and the nature of the rocks on the surface and search for signs of water or ice below the surface with its ground-penetrating radar. The mission will also test technologies needed for a potential Mars sample return mission late in the 2020s.
Typically, China does not provide a live feed or video of its space operations. Given the high-profile nature of the Zhurong landing, that may change with this mission. This post will be updated if a feed becomes available.