With multiple countries now on their way to the Red Planet, 2020 is the year of Mars. The United Arab Emirates kicked things off by launching its first Mars probe on July 19. China launched its own probe to the planet four days later. Then on Thursday, the US launched another mission to Mars.
The missions from China and the US are the only ones with rovers that will land on Mars. (The UAE’s Hope mission only sent an orbiter that will monitor the planet from space.) This is also China’s first Mars mission, and it differs greatly from what the US sent up. Here’s a look at how they compare.
China’s rover has a much shorter mission. It’s designed to operate on the planet for three Martian months, or roughly 92 Earth days. Mission team members say that if landed, the rover will map the geological structure of Mars, investigate the surface soil and water-ice distribution, and measure the Martian climate, among other things.
What are they made of?
Weighing 240 kilograms (529 pounds), China’s 1.8-meter-tall (5.9 feet) rover is much smaller than Nasa’s 2.2-meter-tall (7.2 feet) Perseverance rover, which weighs 1,025 kilograms (2,260 pounds). Based on the successful design of Nasa’s previous Mars rover, 2011’s Curiosity, Perseverance is equipped with more parts than China’s.
Perseverance has a robotic arm that helps it extract samples from Mars’ surface and a range of cameras. Nasa also added two microphones for the first time. China’s rover appears to be less complex, with six instruments that include two cameras and no microphones.
Both rovers have six wheels, but the lighter Chinese rover is faster, boasting a speed of 200 meters per hour (0.12 miles per hour). Perseverance moves at 152 meters per hour (0.09 miles per hour). Nasa admits that this is slow by Earth’s standards, but it calls the rover a “standout performer” on Mars.
How are they powered?
China’s Mars rover is solar-powered, with four wing-like solar panels on the top of the vehicle. While Nasa also used solar panels in past Mars missions, the agency found problems with it. One issue is the planet’s dust storms, which can cover the panels and prevent the rover from getting enough solar energy needed for the mission. So Nasa gave its rovers an upgrade.
Perseverance uses a radioisotope power system called Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). In other words, it’s a nuclear-powered rover. Curiosity is also powered by an MMRTG, which can last 14 years. Nasa says this gives the rover greater mobility over a range of latitudes and altitudes, allowing engineers to more flexibly operate it.
Perseverance is also carrying something else: a tiny four-pound helicopter called Ingenuity. It’s a test to see if powered flight is a viable option in the thin Martian atmosphere. If Ingenuity works, it could herald the next step in humanity’s quest to understand the Red Planet.