Two years ago today, NASA’s Perseverance rover made a white landing on the surface of another world. On February 18, 2021, a rocket-powered sky crane lowered the car-sized Perseverance and its tiny companion Ingenuity helicopter to the floor of the Martian crater Jezero before flying for an emergency landing to a safe distance.

Since then, Perseverance and Ingenuity have been extremely busy, like their rulers around the world. But the two-year milestone gives everyone the opportunity to take a step back and evaluate how successful the missions have been so far.

“Anniversaries are a time to reflect and celebrate, and the Perseverance team does a lot of both,” Perseverance project scientist Ken Farley of the Cal Institute of Technology in Pasadena said in a statement from NASA on Friday, February 17.

“Perseverance researched and collected data on hundreds of interesting geological features, collected 15 rock cores and created the first specimen repository on another world,” Farley added. “We hope to refresh this number soon, with the next science campaign known as Top Fan kicking off on February 15.”

Farley said sample collection is one of the main goals of the Perseverance mission. The rover drills through rock cores and collects Martian regolith (dirt and gravel), material that a joint NASA and European Space Agency (ESA) campaign plans to return to Earth as early as 2033. So far, Perseverance has filled 18 out of 38 titanium sample tubes. As Farley notes, two of the fifteen rock cores contain regolith, and one is an “atmosphere sample” obtained after the rover’s initial drilling failed. (The rover also has five “witness tubes” designed to help the mission team determine whether any sealed sample tubes contain contamination from Earth.)

The basic sample return architecture requires ESA to launch the Earth Return Orbiter (ERO) in 2027 and NASA to send a rocket-equipped SRL (Sample Retrieval Lander) to Mars the following year. If all goes according to plan, it will transport the Perseverance sample to the SRL, which will land on the 28-mile-wide (45 kilometers) Jezero. An onboard SRL rocket will then launch the Martian material into orbit, where it will be captured by ERO and pulled back to Earth.

That said, there’s no guarantee that Perseverance will be healthy by the end of the 2020s – and that’s where the warehouse comes in. As a backup, the rover recently dropped 10 sample tubes in an area of ​​the lake that the mission team called Three Forks. If necessary, two Ingenuity-like helicopters taking off at the SRL will collect the storage tubes one at a time and return them to the all-terrain vehicle for launch.

Once the Perseverance samples reach Earth, they will be analyzed by scientists in well-equipped laboratories around the world. Most of these researchers will look for signs of ancient life on Mars, as the Lake was once a habitable environment; Billions of years ago there was a large lake and river delta here.

The six-wheeled robot conducts its own search for life inside Jezero, but such tasks are difficult; Mission team members said confirming the existence of life on Mars may be beyond the capabilities of a lone robot with a limited scientific payload.

Operation Perseverance will soon elevate it from the crater floor to the top of an ancient delta, into an environment the rover has yet to explore. Creativity was not expected to contribute greatly to Perseverance’s mission; The 4-pound (1.8-kilogram) helicopter is a technology demonstrator designed to demonstrate that aerial exploration is possible on Mars despite the planet’s thin atmosphere.

The tiny helicopter did just that, completing its first five-flight mission. He then continued to fly on an extended mission where he served as Perseverance’s spotter. (Perseverance is now also exploring as part of an extended mission; its main mission took a Martian year, which is about 687 Earth days.) Ingenuity has now completed 43 flights, passing the Red Planet, covering about 5.5 miles (8.9 kilometers). land Perseverance travels even better than its air counterpart; the rover read 9.05 miles (14.57 km) on the odometer since landing. And some of their other tricks are really impressive.

For example, mission team members said Friday that the rover had captured more than 166,000 images of Mars with various cameras. Perseverance’s geospatial radar has completed 676,828 underground probes to date, and the SuperCam instrument has fired its rock-absorbing laser 230,554 times.

Persistence and creativity aren’t the only NASA robots exploring the Martian surface.

About the same size as Perseverance, the Curiosity rover has been exploring the 96-mile (154 km) wide Gale Crater since August 2012. Shortly after landing, Curiosity discovered that Gale contained a potentially habitable system of lakes and rivers over long distances in the distant past.