The Curiosity rover and other spacecraft are learning to think for themselves

It takes up to 24 minutes for a signal to travel between Earth and Mars. If you're a Mars rover wondering which rock to drill into, that means waiting at least 48 minutes to send images of your new location to NASA and then receive marching orders. It's a lot of idle time for a robot that cost $2.6 billion to build. That's why engineers are increasingly giving spacecraft the ability to make their own decisions. Space robots have long been able to control certain onboard systems--to regulate power usage, for example--but artificial intelligence is now giving rovers and orbiters the ability to collect and analyze science data, then decide what info to send back to Earth, without any human input.