PASADENA, California: NASA's most ambitious and expensive Mars mission begins this weekend with the arrival on the planet of the smartest rover ever built.
It won't be easy. The touchdown for the rover called Curiosity is so risky it's been described as "seven minutes of terror." That's the time it takes to slow down from a blazing 13,000 mph (20,920 kph) to a complete stop with the help of a parachute, heat shield and rockets.
In a new twist, the rover will be lowered by cables from a hovering spacecraft.
Scientists on Earth won't know for 14 minutes whether Curiosity lands safely Sunday night.
If all goes well, Curiosity will spend two years trying to figure out if the Mars environment was once suitable for microbes.