Not all rocks are created equal. It’s a mundane but inescapable fact that turns out to be particularly problematic if you’re designing a drill for a robot that will be poking holes in Mars.

But who really worries about such things? A team at NASA’s Jet Propulsion Laboratory, where the newest Mars rover is being readied for a 2020 launch to the red planet.

That’s who.

When it’s millions of miles away from Earth, the new rover will not only need to search for signs of ancient life, it will need to be prepared for all the alien rocks it meets. Especially because, unlike its cousin Curiosity, this next-gen robot won’t just be drilling holes in those