Published 20 May 2021 by Benjamin Skuse

Tianwen-1 Touches Down on Mars

Photo/Credit: Elen11/iStock

On 14 May 2021, the Chinese National Space Agency’s (CNSA) Tianwen-1 lander touched down on the Red Planet, surviving the now infamous ‘seven minutes of terror’ as it travelled from the top of Mars’ atmosphere to the ground.

A 5-tonne orbiter, lander and rover all-in-one package, Tianwen-1 (which means “questions to the heavens”) is China’s first solo outing to the Red Planet. Blasting off from Wenchang Satellite Launch Centre aboard a Chinese Long March-5 rocket on 23 July 2020, Tianwen-1 reached Mars’ orbit on 10 February. It then shrunk its orbit to 265 km and collected images of its target landing site Utopia Planitia in preparation for the release of its lander and Zhurong rover.

Tianwen-1 is one of three new arrivals to the Red Planet this year that took advantage of the biannual Mars launch window in 2020. Sweeping above the planet is the United Arab Emirates’ Hope orbiter. And trundling across the barren Martian landscape is NASA’s Mars 2020, consisting of the Perseverance rover and Ingenuity, a small helicopter that recently completed the first powered flight on another planet. They join two other operational missions on the surface (NASA’s InSight lander and Curiosity rover) and six orbiters (from India, ESA and NASA).

Obsession With the Red Planet

These and dozens of previous missions make Mars one of the most explored bodies in the Solar System. What is it about the Red Planet that holds such fascination for humanity? Common sense would suggest we would be more intrigued by our closest neighbour and one of the brightest points in the night sky – Venus. Yet Venus can’t hold a candle to Mars. Where Venus seems to be going through a hellish and never-ending dramatic global catastrophe, conditions on Mars are calmer and more familiar. Mars looks like the Atacama Desert painted red. It’s certainly easier to imagine life on Mars – either alien or as an outpost for humanity – than Venus, where any traveller would be crushed and boiled within seconds of setting foot on the planet.

Up until the 1960s, Mars was thought to be teeming with life, covered in vegetation and perhaps even Little Green Men. NASA’s Mariner 4 flyby in 1964 changed all that, revealing a cold and crater-pocked dead planet. However, scientific fascination has remained undimmed.

Though intelligent life on Mars is now out of the question, the Red Planet still remains one of our best bets for finding microbial life, ancient or otherwise, in the Solar System. It is also the obvious choice for our first tentative steps into deep space exploration. Mars is far from hospitable, but it is relatively close and the most similar planet to Earth, with a solid surface, calm weather, enough gravity and water and oxygen hidden in the landscape.

All-in-one Planet Surveyor

Tianwen-1 is studying the Red Planet in a variety of ways. The orbiter boasts seven instruments, such as a high-resolution camera, spectrometer, magnetometer and ice-mapping radar instrument to paint a picture of Mars from above. It also relays communications from the rover’s suite of six scientific instruments. These instruments study the topography, geology, soil structure, minerals, rocks and atmosphere of Mars to help solve one of the planet’s biggest mysteries: why did Mars’ ancient water evaporate?

Like Perseverance, the rover is also searching for hints of ancient life and simultaneously laying the groundwork for a future sample return mission planned for the end of the 2020s. Zhurong will gather rocky samples from the surface and set them aside so that future spacecraft can deliver them to Earth.

Collaboration is Key

Though less of an international affair than NASA’s Mars 2020 – whose Perseverance rover boasts instruments from France, Spain and Finland or the United Arab Emirates’ Hope orbiter, involving experts around the world from day one Chinese National Space Agency is seeing the benefits of close links with international partners on the Tianwen-1 mission.

To realise the dream of human beings on Mars international cooperation is needed. Photo/Credit: dottedhippo/iStock

For instance, ESA’s Estrack communication network assisted CNSA in pinpointing Tianwen-1′s position and trajectory during its journey to Mars. And ESA’s Mars Express probe will act as a backup communications relay between the Zhurong rover and Earth when it lands.

Elsewhere, the French Institute for Research in Astrophysics and Planetology has been involved in calibrating the rover’s spectroscopy instrument and the Austrian Research Promotion Agency has assisted in the development and calibration of a magnetometer installed on the orbiter.

Boots on Mars

Looking to the future, spacefaring countries like China and even private businesses such as SpaceX have big plans to return Martian soil samples and put humans on Mars by as early as the 2030s. Though competition has a role to play in galvanising innovation and accelerating development towards these ambitions, space thought-leaders say that such gargantuan feats can only be achieved through international collaboration – pooling resources, capacities and capabilities.

As Tianwen-1 and other successful Mars missions have already shown, working with international partners can reap considerable rewards. But to have any hope of setting foot on Mars, we will need to shed earthbound rivalries and biases – and instead share knowledge openly in the spirit of science without borders.

Benjamin Skuse

Benjamin Skuse is a professional freelance writer of all things science. In a previous life, he was an academic, earning a PhD in Applied Mathematics from the University of Edinburgh and MSc in Science Communication. Now based in the West Country, UK, he aims to craft understandable, absorbing and persuasive narratives for all audiences – no matter how complex the subject matter. His work has appeared in New Scientist, Sky & Telescope, BBC Sky at Night Magazine, Physics World and many more.