The Success of China's Tianwein-1

Why We Need Tianwen-1

Water doesn’t currently exist on Mars' surface, but it used to. We know this from dramatic dry canyons and river channels seen from orbit, as well as minerals on the surface that only form in liquid water.

Around 3 billion years ago, something happened to Mars’ atmosphere, and most of the liquid water evaporated. But some of it may still be underground, safely shielded from harmful solar radiation that bombards the planet’s surface. Could those ancient pockets of water contain life?

China’s Tianwen-1 Mars mission launched on 23 July 2020 amidst the added challenge of the global COVID-19 pandemic. It will, among other things, search for pockets of water using radar mounted on the rover. The European Space Agency’s Mars Express spacecraft found evidence for subsurface water using radar from orbit, but this will be the first time a rover has searched from the ground. (NASA’s Perseverance rover also has a radar instrument; it will launch and land on Mars at about the same time as Tianwen-1.)

Tianwen-1 will give China valuable Mars experience and lay groundwork for a possible sample return mission planned for the end of the 2020s. Getting Martian samples back to Earth is a top priority for the scientific community. Despite the impressive advances made in placing miniature science instruments on spacecraft, only Earth-bound technology can date samples with absolute precision, reproduce scientific results, and verify the presence or absence of life in a sample.

Only NASA has successfully landed and operated spacecraft on Mars. More countries exploring Mars and our solar system means more discoveries and opportunities for global collaboration. Space exploration brings out the best in us all, and when nations work together everyone wins.

How Tianwen-1 Works

China’s first Mars mission, Tianwen-1 is uniquely ambitious. No nation has ever attempted to send an orbiter and rover to Mars on the first try. Getting from space to the Martian surface is a unique challenge that China will be facing for the first time. Mars landings require heat shielding, thrusters, and supersonic parachutes—a teeth-gnashing experience that NASA has dubbed the “7 minutes of terror.” The landing platform and rover are expected to touch down on Utopia Planet the vast Martian plain where NASA’s Viking 2 spacecraft landed in the 1970s, and the site of a shipbuilding yard in the Star Trek universe.

Tianwen-1 will arrive in Mars orbit as a single spacecraft; the rover's landing attempt is not expected until May. Once on Mars, the landing platform will extend a ramp, allowing the rover to roll gently onto the surface—similar to the way China’s Change rovers are deployed. The rover can communicate directly with Earth or use its orbiter for high-speed data relay. The orbiter has its own set of science instruments for studying Mars, including a high-resolution camera that should produce stunning images.

-Ritwik Sharma