Weather permitting, NASA will send its first spacecraft to Mars since 2013 early on Saturday morning. The InSight mission, designed to study the interior of the Red Planet, is the agency’s first Martian lander—a stationary vehicle as opposed to a rover—since the Phoenix spacecraft touched down on Mars in 2008.

We kind of take it for granted that everything on a mission like this will work. NASA really makes it look easy—the last eight rovers, landers, and orbiters it has sent to Mars have all pretty much met or exceeded expectations. But the road to Mars is littered with dozens of failures.

In fact, no other country has ever landed anything on the surface of Mars that survived for more than a few seconds. So with the world’s mixed record of success, here’s a look at a few potential pitfalls that InSight must avoid before it can burrow 5 meters into Mars and study the interior of the planet in-depth for the first time.