Nasa's InSight spacecraft is about to endure "seven minutes of terror" and might end them dead on the Martian surface. The lander is the first spacecraft built to explore deep in the interior of Mars, digging down and trying to understand its core. But based on previous performance it may never get the chance. More Martian craft have got lost trying to make their way through the thin Martian atmosphere than have successfully landed. Even in recent years, spacecraft have regularly failed on their approach and smashed into the surface, not to be heard from again.